dataesr/scientific-paragraphs-categorization huggingface dataset:
Participants People aged 65 years and over who were hospitalised, living in the community, or in institutions, in a developed country were included. Participants could not have kidney failure, cardiac (heart) failure, had not recently been prepared for surgery or undergone surgery, but may have had other chronic or acute illnesses, such as stroke, fracture, diabetes or infection. For mixed populations of older people that included participants aged under 65 years, we excluded participants aged less than 65 years where we had access to the full dataset; but, where only summary data were available, the study was only included where the proportion of those under 65 years was less than 10%. In the same way, when using published data we excluded studies with more than 10% of participants having one or more of the following: kidney failure, cardiac failure or a recent operation; and when using full study datasets, participants diagnosed with any of these conditions (according to individual study criteria) were excluded from analysis.
Selection of studies Titles and abstracts were scanned and all potentially relevant studies obtained in full text. Full text articles in languages other than English were translated. Study inclusion eligibility was assessed independently in duplicate, and disagreements resolved by a third author. We wrote to authors of all studies that appeared to have collected data on at least one reference standard and at least one index test, and in at least 10 people aged 65 years and over, even where no comparative analysis has been published, requesting either that the original authors supply the relevant 2 x 2 table or the original dataset so that we could create 2 x 2 tables. The latter was preferable because it enabled the review authors to remove data relating to any participants aged under 65 years, or with heart failure or kidney disease, and provided the potential to explore e ects of di erent cut points for index tests that provided continuous data.
Data extraction and management A data extraction form, including validity criteria, was developed for the review and tested by all data extractors (LH, AA, NA, AC, DG, AH, SR, AS, SW) on two or three included studies. We   1 ). Data driven cut points were set as the median in the dataset, plus a value higher than the median and lower than the median. The higher cut point was chosen as the point midway between the median and highest value present in the dataset, and the lower cut point as the point midway between the median and the lowest value present. Before analyses were finalised the proposed cut-o s for each included index test were circulated around the review authors for comments (without the results of any of the analyses) and the cut-o s for several index tests were adjusted according to suggested references and accepted levels (details for each cut-o found in Table  1 ).
Library Once the cut-o s were finalised we calculated sensitivity, specificity, positive and negative predictive values (PPV and NPV), positive and NLRs (PLR and NLR) and diagnostic odds ratio (DOR) for each 2 x 2 table. We conducted bivariate random-e ects meta-analyses in Stata/ IC (StataCorp) using metandi for index tests where there were at least four studies or datasets on a single index test and the studies all shared a cut-o for test positivity, so that datasets could be pooled (Reitsma 2005) to construct sensitivity and specificity summary estimates, and summary ROC curves. We assigned the same approach for index tests with continuous outcome data for each of the three cut-o points investigated. Where meta-analyses would not run in STATA we increased the number of integration points, until the meta-analysis would run (Table  2 ).
Cochrane Database of Systematic Reviews We directly compared index tests that fulfilled the minimum criteria of sensitivity ≥ 60% and specificity ≥ 75% where two or more were measured in a single study (direct comparison). We planned that the tests would be compared at their best cut-o point, that is, the point that provided the best discrimination, its threshold nearest to the upper le quadrant of the ROC curve. We also planned bivariate meta-regression to explore including a binary covariate for index test to understand whether the expected sensitivity and specificity or both di ered between index tests (Macaskill 2010). For the review we had to pre-specify three cut-o s for each test with a continuous measure (as above). As this is an area where there is little previously published research the danger was that we chose unhelpful cut-o s and missed a cut-o with useful sensitivity and specificity.
Sensitivity analyses We planned to assess the e ect of four quality items: acceptable delay between tests; incorporation avoided; partial verification avoided; and withdrawals explained; on the results by using each quality assessment item as a covariate in bivariate regression. These four items were chosen for sensitivity analyses because they were not explored within the investigations of heterogeneity and were potentially troublesome even though we had access to full datasets for most included studies. However, given the small number of included studies for each test this bivariate regression was considered inappropriate.
Results of the search The final searches were run in April 2013 (for MEDLINE, EMBASE and CINAHL) (Figure  1 ). A er duplicates were removed from the 6888 records retrieved, 205 records were identified as possibly being relevant, and the full texts of these articles were assessed. Of these, 78 were found not to be relevant to this review. The remaining 134 articles related to 121 studies. We attempted to contact study authors to obtain further information, including whether relevant reference test or index test data were available, and if so, seeking datasets for inclusion in this review. As a result of this process we excluded 90 studies, leaving 24 studies for inclusion in the review. We also identified three ongoing studies (two through database searching, and one through contact with authors).
Methodological quality of included studies The methodological quality of included studies is set out in Characteristics of included studies, and summarised in Figure  2. Representative spectrum assessed whether participants were older people living in the community independently or in care, and whether there was consecutive or random recruitment. We assessed six studies at low risk of bias (included older people living in the community and recruitment was consecutive or random), 13 were at high risk of bias (so participants were not living in the Cochrane Library Trusted evidence. Informed decisions. Better health. Cochrane Database of Systematic Reviews We assessed that 13/24 included studies had a low risk reference standard (serum or plasma osmolality directly observed). Delay between index and reference standard tests is of particular importance in dehydration; hydration status can alter over the course of a few hours.
Our assessment found that 23 studies were at low risk from di erential verification (studies at low risk used the same reference standard in all participants); one was unclear. Furthermore, 22 studies were at low risk of incorporation of index tests into the reference standard, and two were at high risk. There were 20 studies that had reference standard results interpreted blind to index test results, so were at low risk of reference standard results being interpreted according to the index test results; one was at high risk and three at unclear risk. There were 18 studies at low risk from index test results being interpreted according to reference standard test results; six were unclear. We found that 22 studies (including all of those where a dataset was provided) were at low risk of interpreting index or reference tests with reference to other relevant clinical data; two were unclear.
Combining several tests We planned to carry out an exploratory analysis to assess the value of combining the best three index tests where the each had some predictive ability of their own, and individual studies included participants who had all three tests. There were no relevant three tests, but we did carry out an exploratory analysis to combine missing drinks between meals and expressing fatigue in the Kajii 2006 study dataset (Table  5 ). Combining two tests so that a person had to both miss some drinks between meals and express fatigue to be labelled as dehydrated, the test was both sensitive at 0. 71 (95% CI 0. 29 to 0. 96) and specific 0. 92 (95% CI 0. 83 to 0. 97), with PLRs of 9. 14 and NLR of 0. 31. From a pre-test probability of 10% the probability of dehydration with a positive test jumped to 50%, and fell to 3% with a negative test.
Summary of main results We aimed to determine the diagnostic accuracy of state (one time), minimally invasive clinical symptoms, signs and tests (collectively referred to as tests) to be used in screening for waterloss dehydration (and current dehydration) in older people by systematically reviewing studies that have measured a reference standard and at least one index test in people aged 65 years and over. There are few published studies of the diagnostic accuracy of state, minimally invasive clinical symptoms, signs and tests to screen for water-loss dehydration, so to complete the review we sought, analysed and included raw datasets that measured a reference standard and at least one index test in people aged 65 years and over. We found three studies with published diagnostic accuracy data and a further 21 datasets that we analysed and included (using individual participant data).
Library Trusted evidence. Informed decisions. Better health. Cochrane Database of Systematic Reviews point, and no post-hoc ROC plot where estimates of sensitivity were ≥ 60% and specificity ≥ 75%. These tests that should not be used individually included fluid intake, USG, urine colour, urine volume, heart rate, dry mouth, feeling thirsty and BIA assessment of ICW or ECW. Missing drinks between meals and expressing fatigue were both assessed in a single study, and using a combination of these two tests improved the diagnostic utility of the assessment of impending dehydration, suggesting that combining tests may be a useful strategy to develop a diagnostic tool in future. No tests were clearly useful in diagnosing current water-loss dehydration (serum osmolality > 300 mOsm/kg).
Cochrane Database of Systematic Reviews Another potential weakness of the review is that we carried out a large number of analyses, increasing the probability of spurious raised sensitivity and specificity (although not many encouraging results were seen despite the large number of analyses). An advantage of assessing clinical symptoms, signs and tests of waterloss dehydration (including those with either impending or current dehydration, so using the cut-o for the reference tests of ≥ 295 mOsm/kg) is that it could be expected that any marker of impending dehydration would also work as a marker of current dehydration (cut-o > 300 mOsm/kg). When we found that missing drinks between meals appeared to be a good a marker of waterloss dehydration in Kajii 2006 (sensitivity 100% and specificity 77%) as well as of current dehydration (sensitivity 100% and specificity 71%) this encouraged us to feel that this may be a useful marker of dehydration.
While e ort was made to ensure that all relevant studies were included, we are aware of several datasets that exist (or existed) but could not be included because original data could not be supplied. In many cases original datasets could not be found or shared for a variety of reasons including loss over time, computer problems that lost data or made data unreadable or institutional rules that precluded sharing of data Although several of these papers refer to the same individual datasets, it was likely that further studies were not located. Because most publications (including those actually included in the review) were not focused on diagnostic accuracy it is possible that this level of missing data did not reflect any particular publication or data bias in the included data, but this is not certain.
Library Trusted evidence. Informed decisions. Better health. Cochrane Database of Systematic Reviews and duplication of promising tests is also underway (Hooper 2012a). Other types of assessments (such as ultrasound to assess inferior vena cava or right ventricular diameter), have been suggested to have some diagnostic ability in hypovolaemia of people of mixed ages in emergency departments (de Lorenzo 2012; Zengin 2013). However, water-loss dehydration is primarily intracellular dehydration, rather than hypovolaemia, so is unlikely to be assessable in the same way. Datasets are being created in which composite tools or classification trees for assessment of impending dehydration may be developed (Hooper 2012a). We hope to incorporate these results into future updates of this review.
Cochrane Database of Systematic Reviews We need to improve our understanding of the comparability of serum osmolarity and osmolarity (using di erent formulae), as well as changes in weight, to improve our understanding of the comparability of di erent reference standards in older adults. Even more fundamentally we need to better understand how serum osmolality, osmolarity and weight change, as indicators of dehydration, are linked to future health and wellbeing of older people. Once a useful test or composite tool for detection of impending or current water-loss dehydration has been identified and verified (by duplication in similar and less similar populations of older people), its place in the clinical and non-clinical setting needs to be considered. In community settings such a test or tool may be used as an indicator to initiate support to improve drinking and/ or assess medications to improve hydration.
Follow-up Flow • 3/24 did not complete the study so were excluded. Of 21 older participants, reviewers omitted none (dataset did not show participant ages, so although data for one male participant was aged 63 years he could not be removed), all were healthy and none had low serum osmolality (< 275 mOsm/kg) • Method: classified as normal, mildly impaired and coma (no further details of how this was tested) • Timing: as heart rate timing Dry oral mucosa (292 participants) • Method: finger was placed inside cheek or the linguo-maxillary sulcus and assessed as wet or dry • Timing: as heart rate timing Skin turgor, subclavicular (306 participants), anterior forearm (302 participants), anterior thigh (303 participants), sternum (304 participants) • Method: assessed at each of four sites, and positive at each site when fold lasted for ≥ 3 seconds after 3 seconds of pinching • Method: standard method, 9 item instrument, scored from 0 to 30 (where 30 is normal cognition) • Timing: all on same day Neecham confusion scale (308 participants) • Method: standard method, scored from 0 to 30 (where 24 or less suggests delirium) • Timing: all on same day CAM (308 participants) • Method: standard method, 9 operationalised criteria for delirium • Timing: CAM on separate day to other assessments Vigilance A (data not in dataset).
Follow-up Flow • Of 3554 beds in 45 long-term care facilities, 13 facilities participated. 311 eligible participants were randomly selected to participate. Reviewers excluded 3 of these from analyses, 1 for being aged < 65 years, 2 for having serum osmolarity < 275 mOsm/L Notes Data on body temperature, heart rate, blood pressure and vigilance A not presented in dataset, so not useable in analyses. Data on CAM were assessed as any positive measure over 4 weeks, so not necessarily at a time point near the reference standard, so not included in analyses Eaton 1994  (Continued)  Clinical features and settings • Setting: intensive care, surgical higher dependency and neurosurgical high dependency units • Method: scores frequency and severity of eye discomfort, eye dryness and frequency of watery eyes during the evening of a typical day in the last month, with each scored 0 (never experience) to 5 (extremely severe), the highest possible score is 25.
Follow-up Flow • Of 36 recruited participants all appeared in the dataset, 2 were removed as they had renal failure or oedema, and 6 were removed as their serum osmolality was < 275 mOsm/kg, so 28 were included. All 28 had BIA data, but only 17 had MMSE and CAM data Notes • USG and urine colour were assessed in some participants, but as none had raised serum osmolality the data could not be used. CAM was assessed in some participants, but confusion was assessed as absent in all participants in whom it was assessed, so the data could not be used.
Cochrane Database of Systematic Reviews • Method: participant asked to stick out tongue, assessed by touch as damp, mildly dry, moderately dry or severely dry • Timing: within 1 hour of blood sample for serum osmolality Tongue furrowed (31 participants) • Method: participant asked to stick out tongue, assessed by touch as un-furrowed, mildly furrowed, moderately furrowed or severely furrowed • Timing: within 1 hour of blood sample for serum osmolality Skin turgor, back of hand (31 participants) • Method: skin on back of unaffected hand pinched then released, time taken for skin to return to normal timed (in seconds) • Timing: within 1 hour of blood sample for serum osmolality Capillary refill time, fingernail (31 participants) • Method: nail bed of middle finger of unaffected hand pressured until the nail is blanched, release pressure and time return of normal colour (in seconds) • Timing: within 1 hour of blood sample for serum osmolality.
Follow-up Flow • Of 981 people admitted to ICU 90 had hypernatraemia, of whom 69 developed it on the ward so were eligible. 24 were excluded due to missing data by the study authors. Of the remaining 45 participants 37 were aged at least 65 years, and 34 had both serum osmolality and fluid intake data. 34 participants are included in most analyses, but urine osmolality data were available for 27 participants only.
Index and comparator tests All data used were taken from the 30 min recovery period (when mean serum osmolality was highest) Urine volume (10 participants) • Method: urine collected at 30 min after exercise ceased, multiplied up to volume over 24 h • Timing: serum osmolality blood sample taken at the same time as urine collection Thirst (10 participants) • Method: self-completed VAS thirst rating, VAS of 180 mm; 0 mm "not thirsty at all", 125 mm "extremely thirsty" • Timing: serum osmolality blood sample taken at the same time as VAS completion.
Cochrane Database of Systematic Reviews Reduced skin turgor on back of hand (11 participants) • Method: assessed by pinching the middle of the back of the hand, and subjectively deciding whether obviously altered, by examiner. Not formally timed. • Timing: immediately after the race and before drinking any fluids Unable to spit (11 participants) • Method: asked to spit into a cup, marked as able to or not • Timing: immediately after the race and before drinking any fluids Feels thirsty (11 participants) • Method: asked whether they feel thirsty • Timing: immediately after the race and before drinking any fluids.
There were 151 patients in the original dataset provided to the reviewers; aged < 65 years (63), kidney disease (10), cardiac insufficiency (33), in shock (1), invalid weight data, as stayed in ICU longer than 7 days (2), surgical procedure while in hospital (15). This le 27 participants to contribute data to the systematic review Notes Cochrane Database of Systematic Reviews BIA resistance at 50kHz (22 participants) • Method: measured on le and right sides using a Real Time Analyzer, RJL Systems, average of le and right measurements used for each participant • Timing: tests completed within 1 to 3 days of admission or in the outpatient centre at time of routine office visits TBW by BIA at 50kHz (22 participants) • Method: measured on le and right sides using a Real Time Analyzer, RJL Systems, average of le and right measurements used for each participant • Timing: tests completed within 1 to 3 days of admission or in the outpatient centre at time of routine office visits ECW by BIA at 50kHz (22 participants) • Method: measured on le and right sides using a Real Time Analyzer, RJL Systems, average of le and right measurements used for each participant • Timing: tests completed within 1 to 3 days of admission or in the outpatient centre at time of routine office visits Follow-up • Of 82 volunteers, 63 participants were included in the published data.
Cochrane Database of Systematic Reviews • Timing: time between blood sample and assessment of eyes unclear Skin turgor (29 participants) • Method: assessed by internal medicine residents, abnormal when anterior chest skin returned to its normal position slowly after being pinched between examiners thumb and forefinger • Timing: time between blood sample and assessment of skin unclear Capillary refill time (27 participants) • Method: assessed by internal medicine residents, slow when normal colour took more than 2 seconds to return after distal phalanx of patient's middle finger was compressed for 5 sec when level with the patients heart • Timing: time between blood sample and assessment of finger unclear.
Cochrane Database of Systematic Reviews • Method: asked (in a paper-based questionnaire, with verbal instructions) whether was experiencing the symptom, and if "yes" asked to state severity on 100 mm VAS (with no symptoms marked as 0), severe symptoms at top of scale. Symptoms included balance problems, headache, nausea, dry mouth, muscle weakness, tiredness, thirst, dizziness. • Timing: time 0 (baseline) before infusion, the same time as serum osmolality blood sample obtained Follow-up • 168 patients were asked whether they would like to participate, of whom 102 were excluded as they did not meet the inclusion criteria  (79)  or did not give informed consent or presented logistic problems. Of the 66 participants recruited, 41 were aged at least 70, the remaining 15 participated in the younger group (not analysed here).
Yes Financial support was provided through the regional agreement on medical training and clinical research (ALF) between Stockholm County Council and Karolinska Institutet and an unrestricted grant by Masimo Inc. , Irvine, CA. (Masimo Inc produce the spectrophotometric adhesive sensor used to monitor haemoglobin concentration, peripheral perfusion index, oxygen saturation, and pulse rate). These measures were not relevant to our review Sjöstrand ED 2013  (Continued)  Clinical features and settings Cochrane Database of Systematic Reviews • • Timing: time 0 (baseline) in IV arm of intervention study, the same time as serum osmolality blood sample obtained Participant expression of symptoms (13 participants) • Method: asked whether was experiencing the symptom, and if "yes" asked to state severity on 100 mm VAS (with no symptoms marked as 0), severe symptoms at top of scale.