title: A Systematic Review of the Impact of Potentially Inappropriate Medication on Health Care Utilization and Costs Among Older Adults.
abstract: BACKGROUND
  Potentially inappropriate medications (PIMs) are defined as those medicines having a greater potential risk than benefit for older adults. In this systematic literature review, we evaluate the current evidence on health care service use and health care costs associated with PIMs among older adults.
  
  
  METHODS
  A literature search was conducted in August 2015 without publication date restrictions using the databases PubMed and Scopus. Selected articles included in the review of articles were: (1) observational cohort or case-control, or intervention studies; (2) investigating PIM use among older adults aged 65 years or older with outcomes on health care utilization (eg, hospitalization) or health care costs; and (3) use of some published criteria for assessing PIMs.
  
  
  RESULTS
  Of 825 abstracts screened, in total 51 articles proceeded to full-text review. Of those full-text articles, 39 articles were included in this review. Most of the articles found that PIMs had a statistically significant effect on health care service use, especially on hospitalization, among older adults. The findings of impact on length of stay or readmissions were inconclusive. Five studies found statistically significant higher medical or total health care costs for PIM users compared those who did not use any PIMs.
  
  
  CONCLUSIONS
  PIMs can, in addition to health and quality of life problems, also lead to greater health care service use and, thus, higher health care costs. However, the heterogeneity of the study settings makes the interpretation of the results difficult. Further studies, especially on economic issues with country-specific criteria, are needed.
authors.affiliation: *Department of Health and Social Management, University of Eastern Finland †Finnish Medicines Agency, Assessment of Pharmacotherapies, Kuopio, Finland.
authors.forename: Virva
authors.initials: V
authors.lastname: Hyttinen
authors.forename: Johanna
authors.initials: J
authors.lastname: Jyrkkä
authors.forename: Hannu
authors.initials: H
authors.lastname: Valtonen
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D003695:Delivery of Health Care / Q000191:economics / Q000706:statistics & numerical data*; D005260:Female; D017048:Health Care Costs / Q000706:statistics & numerical data*; D006760:Hospitalization / Q000191:economics / Q000706:statistics & numerical data; D006801:Humans; D057970:Inappropriate Prescribing / Q000009:adverse effects / Q000191:economics*; D008297:Male