Age-Specific Search Strategies for Medline Background Many clinicians and researchers are interested in patients of a specific age -LRB- childhood , geriatrics , and so on -RRB- . Searching for age-specific publications in large bibliographic databases such as Medline is problematic because of inconsistencies in indexing , overlapping age categories , and the spread of the relevant literature over many journals . To our knowledge , no empirically tested age-specific search strategies exist for Medline . Introduction Clinicians and researchers seeking research reports for specific age categories , including generalists and those who are engaged in clinical specialties such as adult medicine , geriatric medicine , pediatric medicine , neonatal medicine , or obstetrics , need to target their literature searches so that the information they retrieve is relevant to their patient population . Difficulty in finding pertinent evidence contributes to the challenges health professionals have in keeping up-to-date and practising evidence-based medicine -LSB- 1-7 -RSB- . Finding age-specific evidence in Medline is a difficult task for several key reasons . In large bibliographic databases such as Medline , optimal search retrieval for individual topics is hampered by the overwhelming amount of available information that is not pertinent to the question . When users search in Medline they have the potential to retrieve articles from any of the approximately 4800 journals that are currently indexed in the database . The size of this general purpose biomedical database coupled with imperfections in indexing -LSB- 1-3 -RSB- lead to a high risk of missing articles that are relevant to the topic of the search while at the same time retrieving many articles that are off target . Effective ways to refine the search may be helpful for those wanting to keep up-to-date and for those looking for an answer to a specific patient care question . Searching in Medline for a specific patient population by selecting `` age-specific '' journals will not help because studies relevant to any age group are scattered through a wide range of journals , including general journals that cater to no particular age group . Moreover , in Medline , the indexing practices used to identify the ages of those involved in a study are so liberal that they create a very imprecise representation of the age categories of the participants within the study . Medline indexers apply all relevant age-specific index terms to an article regardless of how many participants fall within that category . Thus , if just one patient or participant in the study falls into a particular age category , that age-specific medical subject heading -LRB- MeSH -RRB- term will be applied . For example , if a researcher was interested in intercultural communication in family medicine around issues of newborn care , the study by Harmsen and colleagues -LSB- 8 -RSB- might be retrieved using the following index terms : infant , newborn ; ethnic groups ; communication ; and family practice . However , looking at the patient population studied , only 0.9 % of the participants were children under the age of 12 years -- likely very few of these were newborns . The study included participants from many age categories , resulting in eight age-specific index terms being assigned to this article -LRB- infant , newborn ; infant ; child , preschool ; child ; adolescent ; adult ; middle aged ; and aged -RRB- . For searchers who are interested in communication around newborn issues , this article is likely not useful even though the indexing indicates that it is potentially relevant . These age-classification problems are compounded by the less than optimal search strategies used by clinicians , including their lack of knowledge about how to narrow searches without missing relevant information , and their uncertainty about when to stop searching -LSB- 9,10 -RSB- . To assist clinicians searching for studies on age-specific patient populations , we have developed and tested Medline search strategies for detecting studies for specific age categories as well as tested age-specific search terms pertinent to five age-related clinical specialties . In this paper , we report on the evaluation of the retrieval performance of age-specific search strategies in Medline compared with a manual review -LRB- the `` gold standard '' search -RRB- of each article in every issue of 161 journals in the year 2000 . Search strategies are useful tools when searching in large electronic databases . We previously developed search strategies for use in Medline to detect clinically relevant scientifically sound articles in the areas of causation , prognosis , treatment , and diagnosis -LSB- 11-15 -RSB- . After publishing our initial work on search strategy development -LSB- 15 -RSB- , we were approached by neonatologists and gerontologists to develop age-specific search strategies because they expressed frustration with the inefficiency of the current system for finding content specific to their patient population . Using only the age-related MeSH terms when searching can be time-consuming because retrievals can be very large and imprecise . To our knowledge , no empirically developed age-specific search strategies have been previously reported for Medline . Methods The study compared the retrieval performance of age-specific search terms and phrases in Medline -LRB- accessed using Ovid -RRB- with a manual review of each article in every issue of 161 journal titles for the year 2000 . The 161 journals were chosen over several years in an iterative process based on a hand search review of over 400 journals . The journals were recommended by clinicians , librarians , editors , and publishers and were chosen based on Science Citation Index impact factors and ongoing assessment of their yield of studies and reviews of scientific merit and clinical relevance -LSB- 16 -RSB- in the production of 4 evidence-based medicine secondary journals -LRB- ACP Journal Club , Evidence-Based Medicine , Evidence-Based Nursing , and Evidence-Based Mental Health -RRB- . The 161 journals include content for the disciplines of internal medicine -LRB- eg , Annals of Internal Medicine -RRB- , general medical practice -LRB- eg , BMJ , JAMA , and Lancet -RRB- , mental health -LRB- eg , Archives of General Psychiatry , British Journal of Psychiatry -RRB- , and general nursing practice -LRB- eg , Nursing Research -RRB- . Six research assistants hand searched the 161 journals for the year 2000 and collected data on age of the study participants according to our hand search categories defined in Table 1 . This data collection was part of a larger study in which the research assistants applied methodological criteria to each article in each issue to determine if the article was methodologically sound for seven purpose categories -LRB- eg , treatment and diagnosis -RRB- . All purpose category definitions and corresponding methodological rigor have been outlined in previous papers -LSB- 4,17 -RSB- . Research staff were rigorously calibrated for applying all these criteria , including the age classification of study participants , and interrater agreement for application of all criteria exceeded 80 % beyond chance κ = 0.81 ; 95 % CI = 0.79-0.84 -RRB- -LSB- 4 -RSB- . Table 1 Comparison of hand searching and Medline MeSH classification of age categories Hand Search Category Our Definition Medline MeSH Term Category MeSH Definition Fetus Fetus - - Newborn Birth to 1 month Infant , newborn Birth to 1 month Infant > 1 month to < 24 months Infant 1 to 23 months Preschool 2 years to < 6 years Child , preschool 2 to 5 years Child 6 years to < 13 years Child 6 to 12 years Adolescent 13 years to < 19 years Adolescent 13 to 18 years Adult 19 years to < 45 years Adult 19 to 44 years Middle age 45 years to < 65 years Middle aged 45 to 64 years Aged 65 years to < 80 years Aged 65 to 79 years Aged 80 ≥ 80 years Aged , 80 and over 80 years and over ND Nondiscernible - - MeSH terms and textwords related to age -LRB- eg , infant , child , adult -RRB- were downloaded from Medline and were treated as `` diagnostic tests '' for detecting studies with an age-specific population as determined by a hand search of the literature from 161 journals -LRB- the gold standard -RRB- . The hand search data were obtained by reading each issue completely . The downloaded Medline data from the 161 journals included the retrieval sets for each of the individual terms . After these two data sources were obtained -LRB- ie , the Medline downloads and the hand search review -RRB- , a database was created that included the matched merged content from these two sources . These Ovid retrieval sets were then manipulated by our own set of programs to calculate our outcome measures -- the operating characteristics of each age-specific searching term -LRB- eg , sensitivities , specificities , and precision -RRB- for individual terms and for combinations of terms . When we merged the two data sets -LRB- Medline and hand search -RRB- , we determined the match . If Medline included an item that was not indexed , we went back to the journal and scored it . If we had scored an item that was not in Medline , we removed it from the merged database . Therefore , the final merged database included only items that had hand search scores and Medline indexing . This merged database was used to develop the age-specific search strategies -LSB- 17 -RSB- . Borrowing from the concepts of diagnostic test evaluation and library science , we determined the sensitivity , specificity , precision , and accuracy of single - and multiple-term Medline searches . We considered these operating characteristics as the indicators of search term performance . Sensitivity for a given age-specific topic is defined as the proportion of relevant articles -LRB- ie , articles with the desired age-specific content -RRB- that are retrieved ; specificity is the proportion of nonrelevant articles -LRB- ie , articles that are outside the desired age-specific content -RRB- not retrieved ; precision is the proportion of retrieved articles that are relevant -LRB- a library science term that is equivalent to `` positive predictive value '' in diagnostic test evaluation -RRB- ; and accuracy is the proportion of all articles that are correctly classified -LRB- ie , overall proportion of relevant articles retrieved and nonrelevant articles not retrieved -RRB- . Our hand search of the 161 journals indexed in Medline led to the classification of all articles in these journals for age-related content . Search terms were then tested to determine their performance in retrieving age-relevant articles while eliminating those that were nonrelevant . An automated process -LRB- which we developed and implemented using a computer program -RRB- was used to calculate the operating characteristics -LRB- performance -RRB- for each single and combination term in Medline . Formulae for calculating the operating characteristics -LRB- ie , sensitivity , specificity , precision , and accuracy -RRB- of searches are shown in Table 2 . Table 2 Formulae for calculating the sensitivity , specificity , precision , and accuracy of searches for detecting age-specific articles * Hand Search Detection of Search Terms Meets Criteria Does Not Meet Criteria Detected a b Not detected c d a + c b + d * Sensitivity = a / -LRB- a + c -RRB- ; precision = a / -LRB- a + b -RRB- ; specificity = d / -LRB- b + d -RRB- ; accuracy = -LRB- a + d -RRB- / -LRB- a + b + c + d -RRB- . All articles classified during the manual review of the literature , n = -LRB- a + b + c + d -RRB- . Individual search terms with sensitivity > 25 % and specificity > 75 % for a given age category were incorporated into the development of search strategies that included two or more terms . All combinations of terms used the Boolean `` OR . '' For the development of multiple-term search strategies to either optimize sensitivity or specificity , we tested all two-term search strategies with sensitivity of at least 75 % and specificity at least 50 % . To construct a comprehensive set of search terms , a list of MeSH terms and textwords was initially generated , and input was sought from clinicians and librarians in the United States and Canada through interviews with known searchers , requests at meetings and conferences , and requests to the National Library of Medicine . These experts were asked which terms or phrases they used when searching for age-specific studies , as well when searching for studies in specific purpose categories . Search terms could be MeSH terms , including publication types and subheadings , or textwords specific to age in titles and abstracts of articles . Various truncations were also applied to the textwords , phrases , and MeSH terms . We compiled a list of 543 age-specific terms -LRB- Multimedia Appendix -RRB- . All terms were tested in Medline using the Ovid Technologies searching system . Age categories for the hand search were modeled from the MeSH terms used to index age content . A comparison of hand search categories and MeSH term definitions is shown in Table 1 . The major difference between the hand search age categories and the MeSH terms is in how they were applied . During the hand search , we classified the age of study participants in primary studies or review articles in the following way : select one age category , if possible , or up to three to represent where ≥ 50 % of participants fell . This procedure is intended to more accurately represent the focus of age-category research of clinical relevance than the comprehensive indexing of all participants ' ages provided by the Medline index terms -LRB- which may be more pertinent for nonclinical purposes -RRB- . We defined five age-specific specialty areas by collapsing our hand search age categories -LRB- see Table 1 -RRB- and through discussions with clinicians from each specialty area about which definition most appropriately reflected the age of their patients in clinical practice : geriatric medicine -LRB- ≥ 65 years of age -RRB- , adult medicine -LRB- 19 to < 65 years of age -RRB- , pediatric medicine -LRB- > 1 month to < 19 years of age -RRB- , neonatal medicine -LRB- birth to 1 month -RRB- , and obstetrics -LRB- fetus -RRB- . Results Tables 3 to 7 show the operating characteristics of top-performing combinations of terms with best sensitivity , best specificity , and best optimization of sensitivity and specificity while minimizing the difference between the two , for detecting studies on geriatric medicine , adult medicine , pediatric medicine , neonatal medicine , and obstetrics in Medline in 2000 . Search strategies are reported using Ovid 's search engine syntax for Medline -LRB- mp = multiple posting -- term appears in title , abstract , or subject heading ; sh = subject heading -LSB- MeSH term -RSB- ; tw = textword -- word or phrase appears in title or abstract ; : = truncation ; pt = publication type ; exp = explode -- a search term that automatically includes closely related MeSH terms ; tu = therapeutic use as a subheading ; xs = exploded subheading -RRB- . Geriatric Medicine The single term `` exp adult '' yielded the best sensitivity -LRB- 96.4 % -RRB- with a specificity of 55.9 % for retrieving articles about geriatric medicine . However , by using the next best sensitivity combination , `` aged.sh . OR age : . tw . '' , a small sacrifice in sensitivity -LRB- 1 % absolute decrease -RRB- resulted in a much better specificity compared with the most sensitive term -LRB- absolute increase 14.4 % -RRB- and improved precision -LRB- absolute increase 5.2 % -RRB- and accuracy -LRB- absolute increase 13.3 % -RRB- . As expected , precision improved slightly when specificity was maximized -LRB- absolute increase 8.6 % -RRB- . The term that yielded the best optimization of sensitivity and specificity , `` aged.sh . '' , resulted in 93.6 % sensitivity and 82.7 % specificity . Table 3 Combination of terms with the best sensitivity , best specificity , and best optimization of sensitivity and specificity for detecting studies about geriatric medicine -LRB- ≥ 65 years -RRB- in Medline in 2000 Search Strategy * Operating Characteristics † Sensitivity , % -LRB- 95 % CI -RRB- -LRB- n = 3309 -RRB- Specificity , % -LRB- 95 % CI -RRB- -LRB- n = 45719 -RRB- Precision , % ‡ -LRB- 95 % CI -RRB- Accuracy , % -LRB- 95 % CI -RRB- -LRB- n = 49028 -RRB- Best sensitivity -LRB- exp adult -RRB- 96.4 -LRB- 95.8-97.1 -RRB- 55.9 -LRB- 55.5-56.4 -RRB- 13.7 -LRB- 13.2-14.1 -RRB- 58.7 -LRB- 58.2-59.1 -RRB- Next best sensitivity -LRB- aged.sh . OR age : . tw . -RRB- 95.4 -LRB- 94.7-96.1 -RRB- 70.3 -LRB- 69.8-70.7 -RRB- 18.9 -LRB- 18.2-19.4 -RRB- 72.0 -LRB- 71.6-72.3 -RRB- Best specificity -LRB- aged , 80 and over.sh . OR of age.tw . -RRB- 63.3 -LRB- 61.7-65.0 -RRB- 84.0 -LRB- 83.7-84.4 -RRB- 22.3 -LRB- 21.5-23.1 -RRB- 82.6 -LRB- 82.3-83.0 -RRB- Next best specificity -LRB- aged.sh . -RRB- 93.6 -LRB- 92.8-94.5 -RRB- 82.7 -LRB- 82.4-83.1 -RRB- 28.2 -LRB- 27.3-29.0 -RRB- 83.5 -LRB- 83.1-83.8 -RRB- Best optimization of sensitivity and specificity -LRB- aged.sh . -RRB- 93.6 -LRB- 92.8-94.5 -RRB- 82.7 -LRB- 82.4-83.1 -RRB- 28.2 -LRB- 27.3-29.0 -RRB- 83.5 -LRB- 83.1-83.8 -RRB- * Search strategies are reported using Ovid 's search engine syntax for Medline -LRB- if a single search term is shown , this term outperformed two - and three-term combinations -RRB- . Best sensitivity while keeping specificity ≥ 50 % ; Best specificity while keeping sensitivity ≥ 50 % ; Best Optimization of Sensitivity and Specificity is based on lowest possible absolute difference between sensitivity and specificity ; exp = explode , a search term that automatically includes closely related indexing terms ; sh = subject heading ; : = truncation ; tw = textword -LRB- word or phrase appears in title or abstract -RRB- . † Total database has 49028 articles , of which 3309 articles are relevant to geriatric medicine and 45719 are irrelevant to geriatric medicine . ‡ n varies by row . Adult Medicine The three-term strategy `` adult.mp . OR middle aged.sh . OR age : . tw . '' yielded the best sensitivity -LRB- 94.9 % -RRB- and had a specificity of 64.5 % for retrieving articles about adult medicine . When specificity was maximized -LRB- 85.2 % -RRB- with the single term `` middle aged.sh . '' , sensitivity lowered to 72.3 % , but precision improved to 62.1 % -LRB- absolute increase 14.8 % -RRB- and accuracy improved as well -LRB- absolute increase 9.8 % -RRB- . The best optimization of sensitivity and specificity occurred with the combined terms `` middle aged.sh . OR of age.tw . '' , with values approaching 79 % . Table 4 Combination of terms with the best sensitivity , best specificity , and best optimization of sensitivity and specificity for detecting studies about adult medicine -LRB- 19 to < 65 years -RRB- in Medline in 2000 Search Strategy * Operating Characteristics † Sensitivity , % -LRB- 95 % CI -RRB- -LRB- n = 12307 -RRB- Specificity , % -LRB- 95 % CI -RRB- -LRB- n = 39721 -RRB- Precision , % ‡ -LRB- 95 % CI -RRB- Accuracy , % -LRB- 95 % CI -RRB- -LRB- n = 49028 -RRB- Best sensitivity -LRB- adult.mp . OR middle aged.sh . OR age : . tw . -RRB- 94.9 -LRB- 94.5-95.3 -RRB- 64.5 -LRB- 64.4-64.9 -RRB- 47.3 -LRB- 46.6-47.8 -RRB- 72.1 -LRB- 71.7-72.5 -RRB- Best specificity -LRB- middle aged.sh . -RRB- Next best specificity -LRB- adult.sh . -RRB- 72.3 -LRB- 71.5-73.1 -RRB- 75.3 -LRB- 74.6-76.1 -RRB- 85.2 -LRB- 84.8-85.5 -RRB- 81.4 -LRB- 81.0-81.8 -RRB- 62.1 -LRB- 61.3-62.8 -RRB- 57.6 -LRB- 56.8-58.4 -RRB- 81.9 -LRB- 81.6-82.3 -RRB- 80.0 -LRB- 79.5-80.3 -RRB- Best optimization of sensitivity and specificity -LRB- middle aged.sh . OR of age.tw . -RRB- 78.7 -LRB- 78.0-79.4 -RRB- 77.9 -LRB- 77.4-78.3 -RRB- 54.4 -LRB- 53.7-55.1 -RRB- 78.1 -LRB- 77.7-78.5 -RRB- * Search strategies are reported using Ovid 's search engine syntax for Medline -LRB- if a single search term is shown , this term outperformed two - and three-term combinations -RRB- . Best sensitivity while keeping specificity ≥ 50 % ; Best specificity while keeping sensitivity ≥ 50 % ; Best Optimization of Sensitivity and Specificity is based on lowest possible absolute difference between sensitivity and specificity ; mp = multiple posting -- term appears in title , abstract , or subject heading ; sh = subject heading ; : = truncation ; tw = textword -LRB- word or phrase appears in title or abstract -RRB- . † Total database has 49028 articles , of which 12307 articles are relevant to adult medicine and 39721 are irrelevant to adult medicine . ‡ n varies by row . Pediatric Medicine The three-term strategy `` child : . mp . OR adolescent.mp . OR infan : . mp . '' yielded the best sensitivity of 98.0 % with a specificity of 81.2 % for retrieving articles about pediatric medicine . When specificity was maximized -LRB- 97.1 % -RRB- with the single term `` children.tw . '' , a striking trade-off in sensitivity occurred as it was lowered to 58.2 % -LRB- absolute decrease 39.8 % -RRB- . Yet , as expected , precision improved -LRB- absolute increase 30.9 % -RRB- . The three-term strategy `` adolescent.tw . OR children.tw . OR child , preschool.sh . '' yielded the best optimization of sensitivity and specificity -LRB- 89.3 % and 87.3 % , respectively -RRB- . Table 5 Combination of terms with the best sensitivity , best specificity , and best optimization of sensitivity and specificity for detecting studies about pediatric medicine -LRB- > 1 month to < 19 years -RRB- in Medline in 2000 Search Strategy * Operating Characteristics † Sensitivity , % -LRB- 95 % CI -RRB- -LRB- n = 2845 -RRB- Specificity , % -LRB- 95 % CI -RRB- -LRB- n = 46183 -RRB- Precision , % ‡ -LRB- 95 % CI -RRB- Accuracy , % -LRB- 95 % CI -RRB- -LRB- n = 49028 -RRB- Best sensitivity -LRB- child : . mp . OR adolescent.mp . OR infan : . mp . -RRB- 98.0 -LRB- 97.4-98.5 -RRB- 81.2 -LRB- 81.1-81.4 -RRB- 24.6 -LRB- 23.8-25.4 -RRB- 82.4 -LRB- 82.1-82.8 -RRB- Best specificity -LRB- children.tw . -RRB- 58.2 -LRB- 56.4-60.0 -RRB- 97.1 -LRB- 97.0-97.3 -RRB- 55.5 -LRB- 53.7-57.2 -RRB- 94.9 -LRB- 94.7-95.1 -RRB- Best optimization of sensitivity and specificity -LRB- adolescent.tw . OR children.tw . OR child , preschool.sh . -RRB- 89.3 -LRB- 88.1-90.4 -RRB- 87.3 -LRB- 87.0-87.6 -RRB- 30.3 -LRB- 29.3-31.3 -RRB- 87.4 -LRB- 87.1-87.7 -RRB- * Search strategies are reported using Ovid 's search engine syntax for Medline -LRB- if a single search term is shown , this term outperformed two - and three-term combinations -RRB- . Best sensitivity while keeping specificity ≥ 50 % ; Best specificity while keeping sensitivity ≥ 50 % ; Best Optimization of Sensitivity and Specificity is based on lowest possible absolute difference between sensitivity and specificity ; mp = multiple posting -- term appears in title , abstract , or subject heading ; : = truncation ; tw = textword -LRB- word or phrase appears in title or abstract -RRB- ; sh = subject heading . † Total database has 49028 articles , of which 2845 articles are relevant to pediatric medicine and 46183 are irrelevant to pediatric medicine . ‡ n varies by row . Neonatal Medicine Best sensitivity -LRB- 95.3 % -RRB- was achieved by the three-term strategy `` infan : . mp . OR child : . mp . OR gestation : . tw . '' , with a specificity of 83.6 % for retrieving articles about neonatal medicine . An expected trade-off occurred in sensitivity -LRB- absolute decrease 41.7 % -RRB- with the most specific term , `` infants.tw . '' -LRB- 98.7 % -RRB- . However , precision increased to 38.2 % -LRB- absolute increase 30.8 % -RRB- and accuracy reached 98.2 % . The three-term strategy `` infan : . mp . OR gestation : . tw . OR neonatal.tw . '' yielded the best optimization of sensitivity and specificity , reaching values of 93 % -LRB- which were the highest among all five specialties -RRB- . Table 6 Combination of terms with the best sensitivity , best specificity , and best optimization of sensitivity and specificity for detecting studies about neonatal medicine -LRB- birth to 1 month -RRB- in Medline in 2000 Search Strategy * Operating Characteristics † Sensitivity , % -LRB- 95 % CI -RRB- -LRB- n = 663 -RRB- Specificity , % -LRB- 95 % CI -RRB- -LRB- n = 48365 -RRB- Precision , % ‡ -LRB- 95 % CI -RRB- Accuracy , % -LRB- 95 % CI -RRB- -LRB- n = 49028 -RRB- Best sensitivity -LRB- infan : . mp . OR child : . mp . OR gestation : . tw . -RRB- 95.3 -LRB- 93.7-96.9 -RRB- 83.6 -LRB- 83.3-83.9 -RRB- 7.4 -LRB- 6.8-7.9 -RRB- 83.8 -LRB- 83.4-84.1 -RRB- Best specificity -LRB- infants.tw . -RRB- Next best specificity -LRB- infants.tw . OR neonatal.tw . -RRB- 53.6 -LRB- 52.6-60.2 -RRB- 67.7 -LRB- 64.0-71.1 -RRB- 98.7 -LRB- 98.6-98.8 -RRB- 98.2 -LRB- 98.0-98.3 -RRB- 38.2 -LRB- 34.9-41.0 -RRB- 33.7 -LRB- 31.0-36.0 -RRB- 98.2 -LRB- 98.0-98.3 -RRB- 97.8 -LRB- 97.6-97.9 -RRB- Best optimization of sensitivity and specificity -LRB- infan : . mp . OR gestation : . tw . OR neonatal.tw . -RRB- 92.5 -LRB- 90.5-94.5 -RRB- 92.6 -LRB- 92.4-92.8 -RRB- 14.7 -LRB- 13.6-15.7 -RRB- 92.6 -LRB- 92.4-92.8 -RRB- * Search strategies are reported using Ovid 's search engine syntax for Medline -LRB- if a single search term is shown , this term outperformed two - and three-term combinations -RRB- . Best sensitivity while keeping specificity ≥ 50 % ; Best specificity while keeping sensitivity ≥ 50 % ; Best Optimization of Sensitivity and Specificity is based on lowest possible absolute difference between sensitivity and specificity ; mp = multiple posting -- term appears in title , abstract , or subject heading ; : = truncation ; tw = textword -LRB- word or phrase appears in title or abstract -RRB- . † Total database has 49028 articles , of which 663 articles are relevant to neonatal medicine and 48365 are irrelevant to neonatal medicine . ‡ n varies by row . Obstetrics The combination of terms `` gestation : . tw . OR fetal.tw . OR pregnancy.tw . '' produced the best sensitivity of 82.0 % , with a very high specificity of 97.1 % for retrieving articles about obstetrics . The maximization of specificity -LRB- reaching almost 99 % -RRB- with the single term `` gestation : . tw . '' yielded a 1.8 % increase in specificity but with a marked trade-off in sensitivity , which decreased to 52.0 % -LRB- absolute decrease 30 % -RRB- . Table 7 Combination of terms with the best sensitivity , best specificity , and best optimization of sensitivity and specificity for detecting studies about obstetrics -LRB- fetus -RRB- in Medline in 2000 Search Strategy * Operating Characteristics † Sensitivity , % -LRB- 95 % CI -RRB- -LRB- n = 516 -RRB- Specificity , % -LRB- 95 % CI -RRB- -LRB- n = 48512 -RRB- Precision , % ‡ -LRB- 95 % CI -RRB- Accuracy , % -LRB- 95 % CI -RRB- -LRB- n = 49028 -RRB- Best sensitivity -LRB- gestation : . tw . OR fetal.tw . OR pregnancy.tw . -RRB- 82.0 -LRB- 78.7-85.3 -RRB- 97.1 -LRB- 97.0-97.3 -RRB- 23.4 -LRB- 21.4-25.3 -RRB- 97.0 -LRB- 96.9-97.1 -RRB- Best specificity -LRB- gestation : . tw . -RRB- 52.0 -LRB- 47.6-56.3 -RRB- 98.9 -LRB- 98.8-99.0 -RRB- 33.6 -LRB- 30.2-36.7 -RRB- 98.4 -LRB- 98.3-98.5 -RRB- Best optimization of sensitivity and specificity -LRB- pregnancy.tw . OR fetal.tw . OR age : . tw . -RRB- 80.7 -LRB- 77.2-84.0 -RRB- 79.3 -LRB- 78.9-79.7 -RRB- 4.0 -LRB- 3.6-4.4 -RRB- 79.3 -LRB- 79.0-79.7 -RRB- * Search strategies are reported using Ovid 's search engine syntax for Medline -LRB- if a single search term is shown , this term outperformed two - and three-term combinations -RRB- . Best sensitivity while keeping specificity ≥ 50 % ; Best specificity while keeping sensitivity ≥ 50 % ; Best Optimization of Sensitivity and Specificity is based on lowest possible absolute difference between sensitivity and specificity ; : = truncation ; tw = textword -LRB- word or phrase appears in title or abstract -RRB- . † Total database has 49028 articles , of which 516 articles are relevant to obstetrics and 48512 are irrelevant to obstetrics . ‡ n varies by row . Discussion Our study shows that selected age-specific search strategies can achieve high retrieval of studies for age-specific populations . Our age-specific search strategies performed differently among the five specialties we investigated . The highest sensitivity and specificity were achieved for pediatric medicine -LRB- 98 % and 81.2 % , respectively -RRB- and neonatal medicine -LRB- 95.3 % and 83.6 % , respectively -RRB- . This finding may be a result of these age groups being more precisely defined and that studies tend to be narrowly focused on them . Search strategies within obstetrics yielded a higher specificity -LRB- 97.1 % -RRB- than sensitivity -LRB- 82 % -RRB- , indicating that this strategy was better at filtering out nonrelevant age-specific articles than retrieving them . The best performing strategy for optimizing sensitivity and specificity was achieved within neonatal medicine -LRB- 92.5 % and 92.6 % , respectively -RRB- . In all cases , precision was low , a consequence of searching in large multi-purpose databases . Future research is focusing on potential ways to improve precision without compromising sensitivity , for example , by searching in journal subsets . A possible limitation to our study is the generalizability of our findings to other publication years as our data was collected in the year 2000 . We believe , however , that our search strategies are robust because no major changes have been made to age-specific MeSH terms since the year 2000 . Moreover , we have previously shown that search strategies developed in 1990 were robust when searching in 2000 -LSB- 18 -RSB- . Another potential limitation of our study is that our interrater agreement for classifying age content did not reach 100 % . However , exceeding the level of agreement achieved in our study -LRB- > 80 % beyond chance -RRB- is rarely done in diagnostic studies . The scope of journals investigated in our journal subset could be a limitation , but we have no indication that these search strategies would perform differently in other journal subsets aside from the precision values reported . Precision is affected by the prevalence of on-target articles within the database . Thus , our precision figures are presented as estimates of search strategy performance . The utility of age-specific filters will vary according to the needs of clinicians and researchers who must weigh the consequences of using a sensitive or specific search . Although a sensitive search will not miss many relevant articles , such searches are less precise and entail time-consuming sorting through irrelevant articles . The narrower yield of a specific search will capture many relevant articles and take less weeding , but it has greater potential for missing key articles . Search Examples To illustrate the use of age-specific search strategies , if a geriatrician was looking for information about current treatment strategies for Huntington disease , she might begin her search by entering the content term `` Huntington disease '' in Medline , which would yield 5907 articles -LRB- Table 8 -RRB- . Table 8 Example : best sensitivity -LRB- keeping specificity ≥ 50 % -RRB- search strategies for detecting treatment studies in geriatric medicine -LRB- patients ≥ 65 years of age -RRB- in Medline -LRB- 1996 to July week 3 , 2005 -RRB- Search Strategy * Content Term Boolean Operator Best Sensitivity Combination Strategy for Treatment Studies Boolean Operator Best Sensitivity Combination Strategy for Geriatric Medicine Number of Articles Huntington disease - - - - 5907 Huntington disease AND clinical trial.mp . OR clinical trial.pt . OR random : . mp . OR tu.xs . - - 901 Huntington disease AND clinical trial.mp . OR clinical trial.pt . OR random : . mp . OR tu.xs . AND exp adult † 483 * Search strategies are reported using Ovid 's search engine syntax for Medline . mp = multiple posting -- term appears in title , abstract , or subject heading ; : = truncation ; pt = publication type ; tu = therapeutic use as a subheading ; xs = exploded subheading ; exp = explode -- a search term that automatically includes closely related indexing terms . † Outperformed two - and three-term combinations . However , sifting through such a large number of articles would be time-consuming and many of these articles would not be relevant to treatment studies in geriatric medicine . By combining the content term `` Huntington disease '' with the most sensitive combination of terms for treatment studies -LRB- clinical trial.mp . OR clinical trial.pt . OR random : . mp . OR tu.xs . -RRB- , the search can be narrowed to 901 articles . Further , by adding the most sensitive strategy for geriatric medicine -LRB- exp adult -RRB- to this search string with the Boolean operator AND , the search is refined to 483 articles , which is much more manageable than the original 5907 articles retrieved from searching the content term only . A sensitive search such as this would be an efficient beginning for researchers interested in conducting systematic reviews . A more specific approach may be especially useful for physicians who do not have time to process an exhaustive search . In the above example , by combining the content word `` Huntington disease '' with the most specific search strategy for treatment studies -LSB- 12 -RSB- , `` randomized controlled trial.mp . OR randomized controlled trial.pt . '' , and the most specific search strategy for geriatric medicine , `` aged , 80 and over.sh . OR age.tw . '' , the search yields five articles -LRB- Table 9 -RRB- . This is a dramatic reduction in the number of articles retrieved by searching the content term alone -LRB- 5907 articles -RRB- , but key articles can be missed . Table 9 Example : best specificity -LRB- keeping sensitivity ≥ 50 % -RRB- search strategies for detecting treatment studies in geriatric medicine -LRB- patients ≥ 65 years of age -RRB- in Medline -LRB- 1996 to July week 3 , 2005 -RRB- Search Strategy * Content Term Boolean Operator Best Specificity Combination Strategy for Treatment Studies Boolean Operator Best Specificity Combination Strategy for Geriatric Medicine Number of Articles Huntington disease - - - - 5907 Huntington disease AND Randomized controlled trial.mp . OR randomized controlled trial.pt . - - 46 Huntington disease AND Randomized controlled trial.mp . OR randomized controlled trial.pt . AND aged , 80 and over.sh . OR of age.tw . 5 * Search strategies are reported using Ovid 's search engine syntax for Medline . mp = multiple posting -- term appears in title , abstract , or subject heading ; pt = publication type ; sh = subject heading ; tw = textword -LRB- word or phrase appears in title or abstract -RRB- . Conclusion Selected age-specific search strategies can enhance the retrieval of studies for clinicians and researchers who need information relevant for a well-defined age-category patient population . The optimal trade-off between sensitivity and specificity should be determined according to the needs of the searcher .

O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O 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