Measuring Medication Adherence in Patients With Schizophrenia: An Integrative Review

PurposeThe purpose of this paper is to assess the validity, reliability and levels of evidence of existing instruments for measuring medication adherence in patients with schizophrenia.BackgroundSchizophrenia is estimated to affect approximately 7 individuals out of 1000 in their lifetimes, with fifty percent of patients attempting suicide. However studies have shown that measuring medication adherence in patients with schizophrenia is difficult and no gold standard currently exists. Without reliable and valid instruments to evaluate non-adherence in this population, research into strategies to improve adherence cannot move forward.Data SourcesThis integrative review used the following search terms: assessing, measuring, medication adherence, schizophrenia, medication non-adherence, validity, reliability and measures. Databases searched included CINAHL, PubMed, PsycINFO and Scopus). Studies were included if they were published from 2000 to 2016. Fourteen instruments were identified from six studies and were included in this review.ResultsAll the instruments assessed were weak in both validity and reliability coupled with having low levels of evidence. Three instruments (two are fairly new) yielded better validity, reliability and sensitivity; however they have not been assessed in broad, diverse samples, so their generalizability remains unclear.ConclusionThis study suggests the need to develop an instrument with adequate validity, reliability, and sensitivity to various patients' characteristics.