Table 1.
Study characteristics
| Study | Search period | Inclusion criteria (patients and medication marked in italics) |
|---|---|---|
| Explorative systematic reviews | ||
| Aziz 2016 | Not limited to February 2015 | Patients with chronic conditions and different payment schemes |
| Human adults | ||
| Published in English | ||
| Evaluation of the effect of medication cost or method of payment on medication adherence | ||
| Clear description of study population and methodological approach | ||
| Only studies without a adherence intervention | ||
| Only randomized controlled trials, cross-sectional, longitudinal and observational/prospective or retrospective cohort studies | ||
| Only original research (review articles, thesis, commentaries, editorial letters, and case studies were excluded) | ||
| Broekmans 2008 | Not limited to December 2006 | Adult patients with chronic non-malignant pain |
| Adult patients with prescribed pain medication | ||
| Original research | ||
| Chen 2015 | January 1990 to September 2013 | Patients after acute coronary syndrome getting secondary prevention pharmacotherapy |
| Humans aged ≥ 18 years | ||
| Subjects hospitalized for an acute coronary syndrome | ||
| Prescription of at least one specified evidence-based medication after hospital discharge (beta-blocker, lipid-lowering agents, antiplatelet agents, ACEIs or ARBS) | ||
| Report of medication usage after hospital discharge | ||
| Measuring medication adherence and reporting its method of measurement | ||
| Only secondary adherence/non-adherence (not initiation) | ||
| At least 2 months follow-up | ||
| Specific follow-up time for calculating medication adherence | ||
| Calculation of medication adherence of patients with at least one filled prescription for the medication of interest during the follow-up time | ||
| All study designs | ||
| Only original research | ||
| Only analysis of the original study population | ||
| Publication in a peer-reviewed journal | ||
| Daley 2012 | Not limited to January 2012 |
Patients with Parkinson
All ranges and duration of anti-parkinsonian treatments |
| All age ranges | ||
| Published in English | ||
| Presenting quantitative/qualitative data | ||
| Gourzoulidis 2017 | Not limited to NR | Patients with diabetes mellitus or heart failure |
| Different study types including retrospective, longitudinal observational cohort or cross-sectional studies (no reviews, meta-analyses, editorials, comments or letters to the editor) | ||
| Co-payment-interventions (introduction of co-payments or increases/decreases in existing co-payments) | ||
| Studies assessing the impact of co-payments on adherence | ||
| Exclusion of other types of cost-sharing, co-insurance, deductibles or caps | ||
| Exclusion of economic evaluations and treatment interventions | ||
| Only English and full-text published articles | ||
| Jaam 2017 | Not limited to May 2016 | Adults patients (≥ 18 years old) with diabetes mellitus type 1 or 2 living in the Middle East and North African region |
| Only original research reporting qualitative or quantitative data | ||
| Studies investigating factors associated with medication adherence | ||
| Patients receiving anti-diabetic medication | ||
| Krueger 2015 | Not limited to March 2014 | Adult patients with chronic heart failure |
| Studies analysing the relationship between age and medication adherence | ||
| Studies relating to pharmacological adherence | ||
| Only original research | ||
| Poor quality studies were excluded | ||
| Published in every language | ||
| Maimaris 2013 | Not limited to May 2013 | Adult population (general or on hypertension treatment) |
| Studies reporting on effects of national or regional (not individual or organisational levels) health system level arrangements (interventions, policies, or programs) on hypertension control | ||
| Adult population, including general population, population on treatment and population with specific comorbidities | ||
| Quantitative studies | ||
| Quantitative studies must report a measure of association between health system arrangement and at least one hypertension outcome of interest | ||
| Different study types including controlled trials, cohort studies and cross-sectional studies | ||
| Published in every language | ||
| Mann 2014 | Not limited to March 2013 | Adult patients with cardiovascular-related chronic conditions (coronary artery disease, hypertension, diabetes, hypercholesterolemia, cerebrovascular disease) |
| Studies assessing drug insurance (intervention) against a comparator group (including various cost-sharing strategies like co-payments, fixed co-payments, co-insurance, deductibles, caps, coverage gaps) | ||
| Different study designs including randomized controlled trials, non-randomized controlled trials, before-after-studies, interrupted time series | ||
| Studies reporting on medication adherence, clinical outcomes, quality of life, health care utilization or costs | ||
| Studies not focussing on health policy, value-based insurance or reference based pricing English published | ||
| Mathes 2014(a) | Not limited to December 2012 | Hepatitis C-infected patients |
| Adult patients with hepatitis C | ||
| Patients getting medication regimes containing ribavirin | ||
| Every study type with quantitative measure of patient implementation adherence Studies analysing potential adherence influencing factor/s | ||
| Studies conducted in WHO-mortality Stratum A (very low child mortality and low adult mortality) | ||
| Published in English or German | ||
| Mathes 2014(b) | Not limited to December 2012 | Patients taking oral anticancer agents |
| Patients ≥ 18 years old with malignant neoplasms | ||
| Patients taking oral anticancer agents | ||
| Studies analysing potential adherence influencing factor/s | ||
| Every study type with quantitative patient adherence measure (no interventional trials) | ||
| Studies not exclusively referring to intentional non-adherence measures | ||
| Published in English or German | ||
| Oosterom-Calo 2013 | Not limited to August 2010 | ≥ 50% heart failure patients |
| Quantitative results were reported | ||
| Studies of at least fair quality | ||
| Evaluations of interventions were not the main purpose | ||
| No descriptive study | ||
| No review paper | ||
| Published in English | ||
| Pasma 2013 | Not limited to February 2011 |
Inflammatory arthritis patients
Used a reproducible definition or validated instrument to measure adherence Provided a statistical measure to reflect the strength of the association between the determinant and adherence No letters, editorials, reviews, RCTs, case reports, qualitative studies and opinion articles |
| Verbrugghe 2012 | NR | Oral anti-cancer drugs |
| Age ≥ 18 | ||
| Strong or moderate methodological quality | ||
| Written in English, French, German or Dutch | ||
| Original research articles published between 1990 and April 2012 | ||
| Studies not conducted in developing countries | ||
| All study designs | ||
| Focused systematic reviews | ||
| Alsabbagh 2014 | Not limited to February 2012 | Patients taking antihypertensive drugs |
| Analysis of the influence of socioeconomic status on adherence to antihypertensive medications | ||
| All study designs | ||
| Published in English or French | ||
| Studies used electronic prescription database as source for nonadherence information | ||
| Multivariable modelling | ||
| Crawshaw 2016 | January 2000 to December 2014 | Adult patients (> 18 years old) after acute coronary syndrome (myocardial infarction and/or unstable angina) getting secondary prevention pharmacotherapy |
| Cross-sectional, retrospective cohort or prospective cohort studies | ||
| Measure of adherence to cardiac medication (antiplatelet agents, ACE inhibitors, ARBs, beta-blockers, lipid-lowering agents, calcium channel blockers or diuretics) | ||
| Standardised measurement of psychosocial variable | ||
| Assessment of strength of association between psychosocial factors and adherence | ||
| Published in English | ||
| Ghidei 2013 | NR to July 2012 | Older HIV-infected individuals |
| Only studies with control group | ||
| All study designs excluding case reports | ||
| Only studies with specified cut-off for adherence (≥ 80%) | ||
| Only studies not focussing on psychiatric disorders | ||
| Patient in the older classification aged > 45 years | ||
| Initial use of antiretroviral therapy at or after 1996 | ||
| Participations actually on antiretroviral therapy | ||
| Participations without substance abuse | ||
| Peer-reviewed articles Only original research | ||
| Hiko 2012 | January 1997 to December 2011 | Adults living with HIV/AIDS |
| Adult patients (aged ≥18 years) living with HIV/AIDS | ||
| Patients receiving antiretroviral therapy | ||
| Patients living in developed and developing countries | ||
| Studies identifying determinants of non-compliance regarding antiretroviral therapy (socioeconomic-related, health service-related, psychosocial- and behavioural-related and clinical-related outcome measures) | ||
| Quantitative evidence from observational analytic epidemiological studies (including prospective and retrospective cohort studies, case-control and comparative cross-sectional studies) | ||
| Published in English | ||
| Lewey 2013 | NR to 04/2010 | Patients receiving statin therapy |
| Studies evaluating adherence to statin therapy and reporting gender, race or ethnicity as a predictor of adherence | ||
| Studies using univariable or multivariable analysis | ||
| Studies reporting quantitative measures of adherence | ||
| Only original data | ||
| Studies reporting adherence to statin therapy and another medication were also included | ||
| Nachega 2015 | January 1980 to September 2014 | Patients receiving antiretroviral therapy |
| Every study design | ||
| Patients living with HIV | ||
| Patients receiving antiretroviral therapy | ||
| Studies assessing treatment adherence via objective or self-reporting measures | ||
| Studies considering employment as a possible adherence influencing factor | ||
| Sinnott 2013 | 1946 to September 2012 | Participants received healthcare from a public insurance scheme |
| Comparator group was the same population/similar population who either did not pay co-payments or experienced no increase in co-payment | ||
| The intervention was co-payment; either an increase in an existing co-payment or the introduction of a co-payment (no other types of cost-sharing, for example, co-insurance) | ||
| Studies included were randomised controlled trials, controlled before and after studies, interrupted time series designs, repeated measures designs, and cohort designs | ||
NR Not Reported