korea became an  aging society  in 2000 , and in 2008 , the prevalence of individuals aged 65  years or older was 10.3  % . in 2018 , korea will become an  aged society  when 14.4  % of its population comprise the elderly , and a  super - aged society  by 2026 [ 1 , 2 ] . to overcome this situation , the korean government introduced a new social insurance scheme for long - term care ( ltc ) in july 2008 . the ltc insurance program provides social services for elderly people with a few functional limitations . the purpose of this insurance system was to meet the markedly increased demand for elderly healthcare as a result of a rapidly aging population , elevated expectations for healthcare , and a change in the pattern of medical conditions in the elderly from acute illness to chronic disability . this insurance uses the ltc grade for denoting how much help is required for an elderly person in their daily lives . after the implementation of ltc insurance , the number of nursing facilities in korea also increased sharply from 1717 locations ( 68,581 people ) in 2008 to 3751 locations ( 116,782 people ) . researchers have documented the widespread incidence of inappropriate medication use in elderly persons and reported an estimated prevalence from 4.8 to 45.6  % [ 511 ] . the proper use of medicines and monitoring for adverse effects are important factors in the treatment of elderly patients . aging is associated with a reduction in first - pass metabolism and therefore an increase in the bioavailability and distribution of drugs , which increases the risk of adverse effects ; these risks grow exponentially when a number of different drugs are used . because of the potentially serious consequences of exaggerated or incorrect prescriptions , screening tools have been created to detect inadequacies in drug prescriptions . in 2012 , the american geriatrics society ( ags ) and an interdisciplinary panel of experts in geriatric care and pharmacotherapy reached a consensus on the 2012 ags beers criteria . fifty - three medications or medication classes encompass the final updated criteria , which are divided into three categories : potentially inappropriate medications ( pims ) or classes to avoid in older adults ; pims or classes to avoid in older adults with certain diseases and syndromes that the listed drugs can exacerbate ; and medications to be used with caution in older adults . elderly nursing home residents regularly receive complex multi - drug therapy because of the presence of both acute and chronic diseases . for this reason , there have been few reports dealing with the prevalence of pim prescriptions or their adverse effects on elderly patients in south korea [ 14 , 15 ] . to our knowledge , there have been no reports on the prevalence of pim prescriptions in south korea ltc facilities using the 2012 version of the beers criteria . hence , we evaluate the frequency of inappropriate medication use in elderly patients admitted to nursing homes in korea by applying the newly revised 2012 ags beers criteria . a retrospective cross - sectional survey study was performed in patients aged 65  years or older , which produced a sample of 824 people admitted to 20 nursing facilities in northwest korea from january 2012 to february 2012 . we excluded four patients who did not take any medications , 259 patients with incomplete medical records , and 32 patients who were not included in any ltci programs . we assessed the patients age , sex , co - medication , comorbidity , activities of daily living ( adl ) , length of stay , grade of ltc insurance for seniors , and the bed size and business type of the ltc care facilities . the ltc grade is based on standards of five areas of physical functions ( adl ) , cognition , behavioral changes ( behavioral problems ) , demand on nursing care , and need for rehabilitation , and judgment standards made in consideration of service necessary according to the state of functions . on a checklist with a maximum score of 100 , a score of 55 and over makes an individual eligible for insured care . categories of ltc grade are defined as follows : grade 1 ( most severe)the elderly person has one of the following handicaps : he or she can not go to or get out of bed unaided ; experiences behavioral difficulties , impaired judgment , and frequent memory loss as a result of severe brain injury ; or completely needs full assistance with all the activities of daily life and records a ltc acknowledgment score of at least 95 ; grade 2 ( severe)the elderly person can not eat , defecate nor dress themselves unaided ; has impaired judgment and memory loss due to dementia ; needs considerable help in moving or moving in a wheelchair ; spends most parts of daily life in bed and records an ltc acknowledgment score of at least 75 but less than 95 ; grade 3 ( moderate)the elderly person partially needs considerable ltc protection ; some degree of help for eating , dressing / undressing , using the toilet , looking after himself or herself , performing household tasks , and performing their everyday activities outside the home ; and records an ltc acknowledgement score of at least 55 but less than 75 ; no grade ( mild)the elderly person needs some help in one or two activities of daily life , including bathing and dressing / undressing and records an ltc acknowledgment score of less than 55 . prescriptions were assessed for the use of pims according to the 2012 ags beers criteria . we focused on evaluating 34 pims to avoid in older adults and one of the categories in the 2012 update to the ags s beers criteria . drug  disease interactions and drugs to be used with caution in geriatric patients were also assessed using the beers criteria . anti - cholinergics include brompheniramine , carbinoxamine , chlorpheniramine , clemastine , cyproheptadine , dexbrompheniramine , dexchlorpheniramine , diphenhydramine ( oral ) , doxylamine , hydroxyzine , promethazine , and triprolidine . cardiovascular medications include alpha blockers , alpha agonists , guanabenz , guanfacine , methyldopa , reserpine ( > 0.1  mg / day ) , anti - arrhythmic drugs ( class ia , ic , iii ) , and amiodarone . central nervous system drugs include tertiary tricyclic antidepressants , antipsychotics , barbiturates , and benzodiazepines . we calculated the descriptive statistics to illustrate characteristics of the study population by comparing persons on pims with those not on pims . the distributions of baseline descriptive statistics are expressed as proportions and means with standard deviations . in the case of categorical variables , cross - tabulations with chi - square tests were used in comparing the differences . for continuous variables , the statistically significant difference in means was determined by the independent t test . concurrent pim use was defined as the number of pim prescriptions within an individual incidence year . logistic regression analysis was performed to identify the risk factors for pim exposure where pim use ( 0 or 1 ) was the dependent variable and the independent variables included age , sex , adl , length of stay , number of comorbidities , number of co - medications , and grade of ltc insurance . use of pims has been consistently associated with female sex , higher number of medications , higher number of chronic diseases , and older age [ 1621 ] . all statistical analyses were performed using spss 18.0 for windows ( spss inc . , chicago , il , usa ) . this study recruited 529 patients ; 221 of these did not use a pim , while the remaining 308 patients were currently taking pims . significant differences between those prescribed and those not prescribed a pim were found for sex , age , deductible class , number of different medications used , number of chronic conditions , total healthcare costs in the previous year , and number of concurrent pims . the average number of medications in the pim group was 4.0    2.3 , while the non - pim group s average number of medications was 6.4    2.9 ( p  <  0.001 ) . in addition , the average number of comorbidities was 3.3    1.4 in the pim group and 3.8    1.5 in the non - pim group ( p  <  0.001 ) . the number of patients whose ltc insurance for seniors was grade 3 was relatively higher in the pim group than it was in the non - pim group . the six most commonly prescribed classes of medicines within the anatomical therapeutic chemical classification system were as follows : central nervous system ( n  =  930 ; 36.4  % ) , alimentary tract and metabolism ( n  =  553 ; 21.6  % ) , cardiovascular system ( n  =  388 ; 15.1  % ) , blood and blood - forming organs ( n  =  236 ; 9.2  % ) , respiratory system ( n  =  115 ; 4.5  % ) , and musculoskeletal system ( n  =  72 ; 2.8  % ) . table  2 presents the number of pims prescribed in ltc facilities.table  1general characteristics of the residents in long - term care facilitiesvariablesnon - pims [ n  =  221 ( % ) ] pims [ n  =  308 ( % ) ] 
 p valueage ( years)81.6    8.980.2    8.40.067sex ( male)64 ( 29.0%)59 ( 19.2%)0.080number of co - medications4.0    2.36.4    2.9<0.001 
 03105 ( 47.5%)51 ( 16.6% )  4582 ( 37.1%)112 ( 36.4% )  6732 ( 14.5%)103 ( 33.4% )  82 ( 0.9%)42 ( 13.6%)number of co - morbidities3.3    1.43.77    1.5<0.001 
 0270 ( 31.7%)58 ( 18.8% )  352 ( 23.5%)90 ( 29.2% )  461 ( 27.6%)66 ( 21.4% )   538 ( 17.2%)94 ( 30.5%)number of adls1.2    1.21.3    1.20.405  adl  bathing8 ( 3.6%)7 ( 2.3%)0.357  dressing52 ( 23.5%)62 ( 20.1%)0.348  eating132 ( 59.7%)209 ( 67.9%)0.054  toileting58 ( 26.2%)87 ( 28.2%)0.611  walking22 ( 10.0%)42 ( 13.6%)0.200length of stay ( months)28.4    25.926.7    29.20.494grade of long - term care insurance for senior  138 ( 17.2%)31 ( 10.1%)0.008 
 283 ( 37.6%)100 ( 32.5% )  3100 ( 45.2%)177 ( 57.5%)bed size of long - term care facilities  < 2954 ( 24.4%)74 ( 24.0%)0.950 
 305966 ( 29.9%)96 ( 31.2% )  60101 ( 45.7%)138 ( 44.8%)business type of long - term care facilities  corporation159 ( 71.9%)223 ( 72.4%)0.908 
 private operator62 ( 28.1%)85 ( 27.6%)values are presented as number ( % ) 
 pim potentially inappropriate medication , adl activities of daily living 
 p value applied to row 47 inclusive 
 p value applied to row 912 inclusive 
 p value applied to row 2022 inclusive 
 p value applied to row 2325 inclusive 
 p value applied to row 2627 inclusivetable  2number of potentially inappropriate medications in the residents of long - term care facilitiesnumber of potentially inappropriate medicationsnumber ( % ) 0221 ( 41.8)1189 ( 35.7)292 ( 17.4)320 ( 3.8)46 ( 1.1)51 ( 0.2)total529 ( 100.0 ) general characteristics of the residents in long - term care facilities values are presented as number ( % ) 
 pim potentially inappropriate medication , adl activities of daily living 
 p value applied to row 47 inclusive 
 p value applied to row 912 inclusive 
 p value applied to row 2022 inclusive 
 p value applied to row 2325 inclusive 
 p value applied to row 2627 inclusive number of potentially inappropriate medications in the residents of long - term care facilities the six most commonly prescribed classes of medications in our patients were as follows : central nervous system ( n  =  271 ; 58.7  % ) , anticholinergics ( n  =  98 ; 21.2  % ) , cardiovascular system ( n  =  50 ; 10.8  % ) , endocrine system ( n  =  22 ; 4.8  % ) , analgesics ( n  =  9 ; 1.9  % ) , and anti - parkinsonian drugs ( n  =  9 ; 1.9  % ) ( table  3 ) . specifically , the most common pim subtype was quetiapine ( n  =  131 ; 28.4  % ) , followed by chlorpheniramine ( n  =  73 ; 15.8  % ) , risperidone ( n  =  30 ; 6.5  % ) , zolpidem ( n  =  27 ; 5.8  % ) , and spironolactone ( n  =  26 , 5.6  % ) ( table  4 ) . multivariate logistic regression analyses were applied , and the factors that exhibited significant associations with pim prescriptions are shown in table  5.table  3six most commonly prescribed potentially inappropriate medications classesmedications class ( atc code)number ( % ) central nervous system ( n05-n06)271 ( 58.7)anticholinergics ( n04a)98 ( 21.2)cardiovascular system ( c)50 ( 10.8)endocrine system ( g03)22 ( 4.8)analgesics ( n02)9 ( 1.9)anti - parkinsonian drugs ( n04 )  9 ( 1.9)medication classes are stratified according to 2012 american geriatrics society beers criteria for potentially inappropriate medication use in older adults ( ) means codes of anatomical therapeutic chemical ( atc ) classificationtable  4prevalence of potentially inappropriate medications according to individual drugsdrugs ( atc code)number ( % ) quetiapine ( n05ah04)131 ( 28.4)chlorpeniramine ( r06ab04)73 ( 15.8)risperidone ( n05ax08)30 ( 6.5)zolpidem ( n05cf02)27 ( 5.8)spironolactone ( c03da01)26 ( 5.6)olanzapine ( n05ah03 )  21 ( 4.5)lorazepam ( n05ba06)19 ( 4.1)alprazolam ( n05ba12)16 ( 3.5)hydroxyzine ( n05bb01)13 ( 2.8)cyproheptadine ( r06ax02)12 ( 2.6)doxazosin ( c02ca04)12 ( 2.6)sliding scale insulin ( a10ab01)12 ( 2.6)amitriptyline ( n06aa09)11 ( 2.4)megestrol ( g03ac05)10 ( 2.2)meloxicam ( n01ac06)9 ( 1.9)benztropine ( n04ac01)7 ( 1.5)nifedipine ( c08ca05)7 ( 1.5)diazepam ( n05ba01)6 ( 1.3)clonazepam ( n03ae01)5 ( 1.1)terazosin ( g04ca03)3 ( 0.6)total462 ( 100)medication classes are stratified according to 2012 american geriatrics society beers criteria for potentially inappropriate medication use in older adults ( ) means codes of anatomical therapeutic chemical ( atc ) classificationtable  5logistic regression analysis for potentially inappropriate medications used in the residents of long - term care facilitiesvariables 
  
 standard error 
 p valueadjusted or ( 95  % ci)age0.0030.0120.8001.00 ( 0.981.02)sex ( female)0.1360.3160.6661.15 ( 0.622.13)number of co - medications  031.00  450.9030.243<0.0012.47 ( 1.533.97 )  671.6880.316<0.0015.41 ( 2.9110.06 )  83.6000.761<0.00136.61 ( 8.24162.68)number of co - morbidities  021.00  30.4880.2710.0731.63 ( 0.862.76 )  40.0740.2780.7910.93 ( 0.541.60 )  50.4380.2940.1371.55 ( 0.872.76)grade of long - term care insurance for seniors 11.00  20.2710.3120.3851.31 ( 0.712.42 )  30.7090.3440.0392.03 ( 1.043.99)adjusted for activities of daily living , length of stay , bed size and business type of long - term care facilitiesgrade of long - term care insurance for seniors made based on standards of five areas of physical functions ( activities of daily living ) , cognition , behavioral changes , demand on nursing care , and need for rehabilitation and judgment standards made in consideration of service necessary according to the state of functions . categories of ltc grade are defined as follows : grade 1 ( most severe ) ; grade 2 ( severe ) ; grade 3 ( moderate ) six most commonly prescribed potentially inappropriate medications classes medication classes are stratified according to 2012 american geriatrics society beers criteria for potentially inappropriate medication use in older adults ( ) means codes of anatomical therapeutic chemical ( atc ) classification prevalence of potentially inappropriate medications according to individual drugs medication classes are stratified according to 2012 american geriatrics society beers criteria for potentially inappropriate medication use in older adults ( ) means codes of anatomical therapeutic chemical ( atc ) classification logistic regression analysis for potentially inappropriate medications used in the residents of long - term care facilities adjusted for activities of daily living , length of stay , bed size and business type of long - term care facilities grade of long - term care insurance for seniors made based on standards of five areas of physical functions ( activities of daily living ) , cognition , behavioral changes , demand on nursing care , and need for rehabilitation and judgment standards made in consideration of service necessary according to the state of functions . categories of ltc grade are defined as follows : grade 1 ( most severe ) ; grade 2 ( severe ) ; grade 3 ( moderate ) the present study focuses on a growing public health problem : inappropriate medication prescriptions in ltc facilities . a disturbingly high level of pims were prescribed ( 58.2  % ) , which is of concern , indicating room for improvement . a comparison with the results from studies conducted previously worldwide is not straightforward owing to variations in methods , such as data and duration of collection , study criteria , and characteristics of the population groups . despite these variations , this prevalence was similar to those observed in the usa , with values of 49  % of elderly patients who were admitted with one or more of the seven most common medical diagnoses   and 55.3  % in those undergoing surgery during their hospitalization , and 56.1  % of those in acute care hospitals in japan . the results described in the multivariate analysis regarding the factors associated with a potentially inappropriate prescription showed that the likelihood was determined by the number of drugs prescribed during the patient s hospitalization . , the results of a logistic regression model showed that multiple diseases and a higher use of drugs during hospital stay predicted pim prescription . multivariate analyses also revealed that the number of drugs prescribed seemed to be one of the most important independent predictors for receiving an inappropriate medication [ 27 , 28 ] . furthermore , inappropriate medication use was higher with the ltc insurance grade 3 , which means less dependence and a requirement of low - level care . this can be explained by the fact that most of the residents in korean ltc facilities have been diagnosed with dementia or another neurodegenerative disorder . considering central nervous system drugs ( 58.7 % ) were the most prescribed class of inappropriate medications , such prescriptions are used to manage behavioral and psychiatric symptoms . when interpreting the findings of the current study , some limitations to the methodology that could bias estimates are worth mentioning . the first limitation lies with the fact that the study was cross sectional , which does not allow us to identify the causal relationship of pim with associated factors in nature . second , the beers criteria have been examined extensively in research since their development and found to be effective in identifying pim and advising close monitoring of certain medications . however , evidence supporting the effectiveness of the beers criteria in consistently reducing the adverse effects of drugs or decreasing costs or mortality is lacking [ 29 , 30 ] . the beers criteria does not take into account geriatric patients in palliative care or hospice , does not detect prescribing omissions , underuse of medications , inappropriate dosing of medications , or duplication of drug classes [ 31 , 32 ] . third , although the information was gathered mainly from a chart review , recall bias may have been a problem because patients reported their current medications through a structured interview that took place before admission , including the duration of treatment and the dosage ; this information may have been inaccurate . fourth , this sample is unlikely to be representative of all koreans because the study was conducted in one region of the country and , therefore , the ability to generalize the findings is questionable . central nervous system drugs ( 58.7  % ) were the most prescribed class of inappropriate medications in korean ltc facilities . inappropriate medication use was associated with the number of co - medications and ltc insurance grade 3 , which means less dependence and a requirement of low - level care . central nervous system drugs ( 58.7  % ) were the most prescribed class of inappropriate medications . there was a relationship between inappropriate medication use and the number of co - medications . the frequency of inappropriate medication prescriptions was higher among patients whose ltc insurance for seniors was grade 3 , which means less dependence and a requirement of low - level care . this retrospective study was carried out after obtaining the permission of the institutional review board of myoung - ji hospital in korea and has been performed in accordance with the ethical standards of the declaration of helsinki . kang soo lee , sang - hwan kim , and hee - jin hwang have no conflicts of interest to declare . kang soo lee , sang - hwan kim , and hee - jin hwang certify that no funding has been received for the conduct of this study and/or preparation of this manuscript .
backgroundelderly residents of long - term care facilities are more vulnerable to being prescribed inappropriate medications because of the high incidence of co - medication in this population resulting from the presence of multiple chronic diseases and also age - related changes in pharmacokinetics and pharmacodynamics.objectivewe evaluated the frequency of potentially inappropriate medications and factors influencing their frequency.methodsa retrospective cross - sectional study was conducted in 20 long - term care facilities located in the northwest regions of south korea for 824 patients aged 65  years and older who were assessed between january and february of 2012 . 
 potentially inappropriate medications were identified using the 2012 american geriatric society s beers criteria . 
 we assessed the relationship between the frequency of potentially inappropriate medications prescribed and patient age , sex , co - medications , comorbidity , activities of daily living , length of stay , grade of long - term care insurance for seniors , and the bed size and business type of the long - term care facility.resultsof the 529 participants who satisfied our inclusion criteria , 308 ( 58.2  % ) had received at least one inappropriate medication according to the 2012 beers criteria . 
 the most frequently prescribed classes of inappropriate medications were central nervous system drugs ( 58.7  % ) , anti - cholinergics ( 21.2  % ) , and cardiovascular medications ( 10.8  % ) . 
 the most commonly used drugs were quetiapine ( 28.4  % ) , chlorpheniramine ( 15.8  % ) , risperidone ( 6.5  % ) , and zolpidem ( 5.8  % ) . 
 inappropriate medication use was associated with the number of co - medications and long - term care insurance grade 3 , which means less dependence and a requirement of low - level care.conclusionscentral nervous system drugs ( 58.7  % ) were the most prescribed class of inappropriate medications . 
 quetiapine was the drug most often given inappropriately ( 28.4  % ) . 
 there was a relationship between inappropriate medication use and the number of co - medications . 
 the frequency of inappropriate medication prescriptions was higher among patients whose long - term care insurance for seniors was grade 3 , which means less dependence and a requirement of low - level care .