The predictive validity of subjective adherence measures in patients with schizophrenia

Detecting medication non-adherence in schizophrenia: A comparison of different methods among outpatients from a North Indian center

Background

The rates of medication non-adherence among Indian patients with schizophrenia are high, and its detection poses problems. Comparisons of suitable measures to detect medication non-adherence in schizophrenia from Indian outpatient settings are scarce.

Aim

This study compared simple and inexpensive methods of detecting medication non-adherence in schizophrenia among outpatients from a tertiary-care center in North India.

Materials and Method

A longitudinal comparison of two self-reports, the Morisky Medication Adherence Questionnaire and the Drug Attitude Inventory-10, clinicians' ratings employing the Compliance Rating Scale, and clinic-based pill counts was conducted among 70 outpatients with schizophrenia. The rates and detection of medication non-adherence, associations with determinants of treatment non-adherence, and agreement between measures were examined at intake and after six months of follow-up (n = 53).

Results

The self-reports had greater ability to detect medication adherence (specificity 41-65%; positive predictive values 25-51%; negative likelihood ratios 0.86-1.14) and moderate ability to detect medication non-adherence (sensitivity 27-65%; negative predictive values 49-69%; positive likelihood ratios 0.78-1.10). They yielded higher medication non-adherence rates, detected changes in medication non-adherence over time, and were associated with the other measures and the well-known correlates of medication non-adherence. Clinicians' ratings and pill counts had high sensitivity (56-90%) but low specificity (35-49%) to detect medication non-adherence.

Conclusion

Self-reports are comparatively better screening options for detecting medication non-adherence among Indian outpatients with schizophrenia. However, the sequential use of different measures could lead to better recognition of medication non-adherence.

Measurement Properties of Existing Patient-Reported Outcome Measures on Medication Adherence: Systematic Review

Background

Medication adherence is essential for improving the health outcomes of patients. Various patient-reported outcome measures (PROMs) have been developed to measure medication adherence in patients. However, no study has summarized the psychometric properties of these PROMs to guide selection for use in clinical practice or research.

Objective

This study aims to evaluate the quality of the PROMs used to measure medication adherence.

Methods

This study was guided by the PRISMA (Preferred Reporting Items for Systematic Review and Meta-Analysis) guidelines. Relevant articles were retrieved from the EMBASE, PubMed, Cochrane Library, Web of Science, and CINAHL (Cumulative Index to Nursing and Allied Health Literature) databases. The PROMs were then evaluated based on the COnsensus-based Standards for the selection of health Measurement Instruments (COSMIN) guidelines.

Results

A total of 121 unique medication adherence PROMs from 214 studies were identified. Hypotheses testing for construct validity and internal consistency were the most frequently assessed measurement properties. PROMs with at least a moderate level of evidence for ≥5 measurement properties include the Adherence Starts with Knowledge 20, Compliance Questionnaire-Rheumatology, General Medication Adherence Scale, Hill-Bone Scale, Immunosuppressant Therapy Barrier Scale, Medication Adherence Reasons Scale (MAR-Scale) revised, 5-item Medication Adherence Rating Scale (MARS-5), 9-item MARS (MARS-9), 4-item Morisky Medication Adherence Scale (MMAS-4), 8-item MMAS (MMAS-8), Self-efficacy for Appropriate Medication Adherence Scale, Satisfaction with Iron Chelation Therapy, Test of Adherence to Inhalers, and questionnaire by Voils. The MAR-Scale revised, MMAS-4, and MMAS-8 have been administered electronically.

Conclusions

This study identified 121 PROMs for medication adherence and provided synthesized evidence for the measurement properties of these PROMs. The findings from this study may assist clinicians and researchers in selecting suitable PROMs to assess medication adherence.

Development of an Item Bank to Measure Medication Adherence: Systematic Review

Background

Medication adherence is important in managing the progression of chronic diseases. A promising approach to reduce cognitive burden when measuring medication adherence lies in the use of computer‐adaptive tests (CATs) or in the development of shorter patient-reported outcome measures (PROMs). However, the lack of an item bank currently hampers this progress.

Objective

We aim to develop an item bank to measure general medication adherence.

Methods

Using the preferred reporting items for systematic review and meta-analysis (PRISMA), articles published before October 2019 were retrieved from PubMed, Embase, CINAHL, the Cochrane Library, and Web of Science. Items from existing PROMs were classified and selected (“binned” and “winnowed”) according to standards published by the Patient-Reported Outcomes Measurement Information System (PROMIS) Cooperative Group.

Results

A total of 126 unique PROMs were identified from 213 studies in 48 countries. Items from the literature review (47 PROMs with 579 items for which permission has been obtained) underwent binning and winnowing. This resulted in 421 candidate items (77 extent of adherence and 344 reasons for adherence).

Conclusions

We developed an item bank for measuring general medication adherence using items from validated PROMs. This will allow researchers to create new PROMs from selected items and provide the foundation to develop CATs.

Housing First Improves Adherence to Antipsychotic Medication Among Formerly Homeless Adults With Schizophrenia: Results of a Randomized Controlled Trial

Adherence to antipsychotic medication is a significant challenge among homeless patients. No experimental trials have investigated the impact of Housing First on adherence among patients with schizophrenia. We investigated whether Housing First in congregate and scattered-site configurations resulted in superior adherence compared to usual care. Adult participants (n = 165) met criteria for homelessness, schizophrenia, and initiation of antipsychotic pharmacotherapy prior to recruitment to an unblinded, 3-arm randomized controlled trial in Vancouver, Canada. Randomization arms were: congregate Housing First (CHF) with on-site supports (including physician and pharmacy services); scattered-site Housing First (SHF) with Assertive Community Treatment; or treatment as usual (TAU) consisting of existing services. Participants were followed for an average of 2.6 years. Adherence to antipsychotic medication was measured using the medication possession ratio (MPR), and 1-way ANOVA was used to compare outcomes between the 3 conditions. Data were drawn from comprehensive pharmacy records. Prior to randomization, mean MPR among participants was very low (0.44–0.48). Mean MPR in the follow-up period was significantly different between study arms (P < .001) and approached the guideline threshold of 0.80 in SHF. Compared to TAU, antipsychotic adherence was significantly higher in SHF but not in CHF. The results demonstrate that further implementation of SHF is indicated among homeless people with schizophrenia, and that urgent action is needed to address very low levels of antipsychotic adherence in this population (trial registration: ISRCTN57595077).

Integrative Review of Mobile Phone Contacts and Medication Adherence in Severe Mental Illness

BACKGROUND

Poor medication adherence is a significant problem in individuals with severe mental illness (SMI). About 50% of people with SMI become nonadherent to treatment in the first month following discharge from the hospital.

OBJECTIVE

This study examined literature in the past decade (2006-2016) on the use of mobile phone contacts in individuals with SMI to improve medication adherence post hospital discharge.

DESIGN

This integrative review used the search terms texting, text messaging, SMS, cell/mobile phone, medication adherence, medication compliance, and mental illness. Databases (CINAHL, PubMed, PsycINFO, and Scopus) and manual searching of reference lists were done. The main inclusion criteria were the use of mobile phone contacts on medication adherence in individuals with SMI. Adults 18 years and older, studies conducted from 2006 to 2016, and studies conducted in English were also criteria for inclusion. Only five studies met criteria for inclusion.

RESULTS

Outcomes from the review showed that mobile phone contacts have been used to improve medication adherence in individuals with SMI and able to provide the four types of social support (instrumental, informational, emotional, and, appraisal). When phone contacts especially text messaging was used as an adjunct to other interventions, it yielded better medication adherence than when used alone. However, results on medication adherence rates were mixed in participants on both psychiatric and nonpsychiatric medications.

CONCLUSION

Although mobile phone contacts are a promising tool to enhance medication adherence after hospital discharge, its effectiveness to increase medication adherence in this population remains inconclusive.

Measuring Medication Adherence in Patients With Schizophrenia: An Integrative Review

PURPOSE

The 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.

BACKGROUND

Schizophrenia 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 SOURCES

This 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.

RESULTS

All 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.

CONCLUSION

This study suggests the need to develop an instrument with adequate validity, reliability, and sensitivity to various patients' characteristics.

Methodological issues associated with preclinical drug development and increased placebo effects in schizophrenia clinical trials

Recent failures to detect efficacy in clinical trials investigating pharmacological treatments for schizophrenia raise concerns regarding the potential contribution of methodological shortcomings to this research. This review provides an examination of two key methodological issues currently suspected of playing a role in hampering schizophrenia drug development; 1) limitations on the translational utility of preclinical development models, and 2) methodological challenges posed by increased placebo effects. Recommendations for strategies to address these methodological issues are addressed.

A systematic review of factors influencing adherence to antipsychotic medication in schizophrenia-spectrum disorders

Adherence to antipsychotics improves outcome in schizophrenia. There is a lack of consensus on which factors most influence adherence behaviour and methodological issues hinder interpretation of existing evidence. A rigorous systematic search designed to identify robustly implicated factors emerging from methodologically rigorous studies narrowed our search to 13 observational studies (total N=6235) relating to adherence, antipsychotics and schizophrenia. Studies varied significantly, with reported adherence rates ranging from 47.2% to 95%. Positive attitude to medication and illness insight were the only factors consistently associated with better adherence, while contradictory results were found for socio-demographic characteristics, symptom severity and side effects. Only distinct aspects of the therapeutic relationship and social support in younger patients were related to good adherence. Antipsychotic type or formulation and neurocognitive functioning did not appear to impact medication adherence. Despite greater methodological rigour in determining studies to include in the present systematic review, it remains difficult to guide clinicians in this vital area and most of the work discussed contained small sample sizes. Future research in this field should therefore prioritise prospective study designs over longer periods and larger samples in naturalistic settings, providing a more appropriate and clinically meaningful framework than widely used cross-sectional designs.

Does adherence therapy improve medication adherence among patients with schizophrenia? A systematic review

Non-adherence to medication is highly prevalent in patients with schizophrenia. Adherence therapy aims to improve medication adherence of these patients by applying techniques of cognitive behavioural therapy, psycho-education, and motivational interviewing. Even though adherence therapy is frequently discussed and researched, its effectiveness is still uncertain. This paper aims to review the effectiveness of adherence therapy on the medication adherence of patients with schizophrenia. To this end, six electronic databases were systematically searched for randomized, controlled trials on adherence therapy from January 2002 to March 2013. Four trials met the inclusion criteria and were incorporated into the review. The findings suggest that adherence therapy does not improve patients' medication adherence in comparison to treatment as usual or a control intervention. However, all the studies reviewed showed high-adherence ratings at baseline. Thus, further well-designed studies that target adherence therapy to patients who are non-adherent to their medication are needed for a more profound understanding of its effectiveness. In addition, if adherence therapy is aimed not only at improving medication adherence, but also to reach an agreement whereby the patient's decision not to take his medication is accepted, the shared decision-making process needs to be assessed as well.

Adherence and Continuation of Treatment with First- and Second-generation Antipsychotics in Schizophrenia

BACKGROUND

Despite a large body of evidence, the issue of differences in adherence and continuation of treatment with first-generation antipsychotics (FGAs) and second-generation antipsychotics (SGAs) in schizophrenia remains unresolved. This study compared adherence and continuation of treatment between patients on SGAs and FGAs and examined the influence of several socio-demographic and clinical variables on adherence in the two antipsychotic groups.

MATERIALS AND METHODS

Two groups, one of 40 patients with schizophrenia on SGAs and the other with 30 patients on FGAs, were compared on clinician-rated and patient-rated measures of adherence over 6 months; a 3-month period prior to intake and a 3-month follow-up period. Mean scores on these measures and the proportion of adherent/non-adherent patients was estimated for both groups.

RESULTS

The two groups did not differ in the 3-month period prior to intake. Over the subsequent 3 months of follow-up, a-fifth of the patients on FGAs became non-adherent, while about 10% of those on SGAs became more adherent. These differences in continuation rates resulted in patients on SGAs being rated as significantly more adherent at the end of this 3-month follow-up period and over the entire 6 months of the study. Differences in adherence and continuation rates between the two groups were primarily driven by the differences between olanzapine and the FGAs. Supervision of treatment by relatives emerged as the only consistent determinant of adherence, but explained only 8% of the variance.

CONCLUSIONS

Patients on certain SGAs, notably olanzapine, are more likely to continue with their treatment that those on FGAs.

Drug attitude and other predictors of medication adherence in schizophrenia: 12 months of electronic monitoring (MEMS(®)) in the Swedish COAST-study

The aim was to investigate clinical predictors of adherence to antipsychotics. Medication use was electronically monitored with a Medication Event Monitoring System (MEMS(®)) for 12 months in 112 outpatients with schizophrenia and schizophrenia-like psychosis according to DSM-IV. Symptom burden, insight, psychosocial function (PSP) and side effects were rated at baseline. A comprehensive neuropsychological test battery was administered and a global composite score was calculated. The Drug Attitude Inventory (DAI-10) was filled in. A slightly modified DAI-10 version for informants was distributed as a postal questionnaire. Non-adherence (MEMS(®) adherence ≤0.80) was observed in 27%. In univariate regression models low scores on DAI-10 and DAI-10 informant, higher positive symptom burden, poor function, psychiatric side effects and lack of insight predicted non-adherence. No association was observed with global cognitive function. In multivariate regression models, low patient-rated DAI-10 and PSP scores emerged as predictors of non-adherence. A ROC analysis showed that DAI-10 had a moderate ability to correctly identify non-adherent patients (AUC=0.73, p<0.001). At the most "optimal" cut-off of 4, one-third of the adherent would falsely be identified as non-adherent. A somewhat larger AUC (0.78, p<0.001) was observed when the ROC procedure was applied to the final regression model including DAI-10 and PSP. For the subgroup with informant data, the AUC for the DAI-10 informant version was 0.68 (p=0.021). Non-adherence cannot be properly predicted in the clinical setting on the basis of these instruments alone. The DAI-10 informant questionnaire needs further testing.

Factors associated with antipsychotic medication adherence in community-based patients with schizophrenia in Hong Kong: a cross sectional study

The purpose of the present study was to examine the factors affecting adherence to antipsychotic medication in patients with schizophrenia registered with a community psychiatric nursing service in Hong Kong. The study was a cross-sectional observational survey; symptoms, drug attitudes, insight, side-effects, and sociodemographic characteristics were measured and explored in terms of their relationship with medication adherence. A total of 584 patients who were visited by community psychiatric nurses (CPN) participated, and 30% of these patients were non-adherent with their antipsychotic medication. Positive treatment attitudes, awareness of the need for treatment, being prescribed clozapine, receiving state benefits, lower levels of symptoms, and fewer side-effects were associated with adherence. The findings from this study suggest that the clinical efforts of CPN to improve adherence should aim to help patients amplify the personal relevance of treatment and modify patients' attitudes towards medication.

Adherence styles of schizophrenia patients identified by a latent class analysis of the Medication Adherence Rating Scale (MARS): a six-month follow-up study

The purpose of this study was to examine patients' response profiles to the Medication Adherence Rating Scale (MARS) and to evaluate the potential of response styles as predictors of the future course of psychotic disorders in terms of rehospitalisation and maintenance of medication. A total of 371 psychiatric in-patients with schizophrenia or schizoaffective disorder who were taking part in a naturalistic long-term study completed a German version of the MARS. A Latent Class Analysis (LCA) was performed. Five latent classes of response styles could be identified: "moderately adherent", "critical discontinuers", "good compliers", "careless and forgetful", and "compliant sceptics". Class membership was found to be related to the severity of symptoms, level of functioning, insight into illness, insight into necessity of treatment, treatment satisfaction and medication side effects. At a six-month follow-up appointment, significant differences between the classes persisted. Participants showing a "good compliers" response pattern had a significantly better prognosis in terms of rehospitalisation rate and maintenance of the original medication than "critical discontinuers". Evaluation of the MARS by studying response profiles provides informative results that reach beyond the results obtained by an evaluation by scores. Patients can be classified into adherence groups that are of predictive value for long-term patient outcome.

The threshold rate of oral atypical anti-psychotic adherence at which paliperidone palmitate is cost saving

OBJECTIVE

To identify, estimate, and compare 'real world' costs and outcomes associated with paliperidone palmitate compared with branded oral atypical anti-psychotics, and to estimate the threshold rate of oral atypical adherence at which paliperidone palmitate is cost saving.

METHODS

Decision analytic modeling techniques developed by Glazer and Ereshefsky have previously been used to estimate the cost-effectiveness of depot haloperidol, LAI risperidone, and, more recently, LAI olanzapine. This study used those same techniques, along with updated comparative published clinical data, to evaluate paliperidone palmitate. Adherence rates were based on strict Medication Event Monitoring System (MEMS) criteria. The evaluation was conducted from the perspective of US healthcare payers.

RESULTS

Paliperidone palmitate patients had fewer mean annual days of relapse (8.7 days; 6.0 requiring hospitalization, 2.7 not requiring hospitalization vs 17.8 days; 12.4 requiring hospitalization, 5.4 not requiring hospitalization), and lower annual total cost ($20,995) compared to oral atypicals (mean $22,481). Because paliperidone palmitate was both more effective and less costly, it is considered economically dominant. Paliperidone palmitate saved costs when the rate of adherence of oral atypical anti-psychotics was below 44.9% using strict MEMS criteria. Sensitivity analyses showed results were robust to changes in parameter values. For patients receiving 156 mg paliperidone palmitate, the annual incremental cost was $1216 per patient (ICER = $191 per day of relapse averted). Inclusion of generic risperidone (market share 18.6%) also resulted in net incremental cost for paliperidone palmitate ($120; ICER = $13). Limitations of this evaluation include use of simplifying assumptions, data from multiple sources, and generalizability of results.

CONCLUSIONS

Although uptake of LAIs in the US has not been as rapid as elsewhere, many thought leaders emphasize their importance in optimizing outcomes in patients with adherence problems. The findings of this analysis support the cost-effectiveness of paliperidone palmitate in these patients.