Table 1

Characteristics of included studies in meta-analysis

StudyStudy settingDisease areaIntervention description*Identified intervention componentsComponents received by control groupSample sizeIntervention delivery style (and personnel)Intervention length (average)
Bailey et al34Hospital clinic, USAAsthmaComprehensive programme integrating a skill-orientated self-help workbook with one-to-one counselling and adherence-enhancing strategiesMultiple components; non-specific techniquesStandard care; education via a standardised set of pamphlets and routine physician encouragement225Telephone calls and in person (specialist)240 min (4×60 min sessions) over unknown period
Berger et al40Telephone calls to patients at home, USAMultiple sclerosisSoftware-supported intervention based on transtheoretical model of change and MIMotivational Interviewing (MI)Standard care plus could telephone help line367Telephone calls (researcher)9 sessions of unknown duration delivered over 3 months
Brown et al29Hospital clinic, UKEpilepsyFormation of III via completion of a self-administered questionnaireImplementation Intention Interventions (III)Standard care plus self-report questionnaires69Questionnaire completion (not in person)One-off intervention of unknown duration
DiIorio et al41Community clinic, USAHIVOne-to-one counselling sessions based on MIMIStandard care; usual adherence education provided in the clinic17In person (routine HCP)5×35 min sessions delivered over 12 months
DiIorio et al42Hospital clinic, USAHIVMI as individual counselling sessionsMIStandard care; usual (extensive) education provided at the clinic213Mostly in person with some telephone calls (routine HCP)5 sessions of 35 min over 12 months
Farmer et al27Community-based clinic, UKType 2 diabetesBrief intervention to elicit beliefs, resolve barriers and form ‘if-then’ plansIf-then planning (III)Standard care plus additional clinic visits for blood tests211In person (clinic nurse)One-off session lasting 30 min.
George et al30Community pharmacies, Australia and TasmaniaHypertensionCommunity pharmacy intervention of one-to-one sessions, monitoring and medication reviewMIStandard care343In person (routine HCP)3 sessions of unknown duration over 6 months
Golin et al39Community clinic, USAHIVMulticomponent MI-based interventionMIGeneral HIV information provided via audio tape, two one-to-one sessions and two mail shots117In person (specialist)2 sessions of unknown duration over 2 months
Hovell et al51Hospital clinic, USATuberculosisAdherence coaching involving interviewing, contingency contracting and shaping proceduresMultiple components; non-specific techniquesStandard care; routine advice at appointments188Telephone calls and in person (researcher)12 sessions of 15–30 min over 6 months
Konkle-Parker et al38Community-based clinics and patients’ own homes, USAHIVAdherence intervention guided by the Information-Motivation-Behavioural Skills (IMB) modelMIStandard care; usual clinic appointments36Telephone calls and in person (nurse practitioner)8 sessions over 24 weeks. Average overall duration 1 h 30 min
Maneesriwongul et al37Hospital outpatients clinic and telephone calls to patients at home, ThailandHIVMI with counsellingMIStandard care; education and provision of leaflets at point of prescribing60Telephone calls and in person (researcher)3 sessions approximately 30 min over a 4 week period
Murphy et al52Community-based clinic, USAHIVMulticomponent and multidisciplinary intervention including behavioural strategies and cognitive behavioural therapyMultiple components; non-specific techniquesStandard care; regular appointments with enquiries about adherence and an additional 30 min appointment for those with problems where medication schedule is written down for them33In person (specialist)5 sessions of unknown duration over 7 weeks
Ogedegbe et al36Community clinic, USAHypertensionPractice-based MI counselingMIStandard care; usual appointments plus additional visits for MEMS downloads160In person (researcher)4 sessions lasting 30–40 min delivered over 12 months
Pradier et al50Hospital clinic, FranceHIVEducational and counselling intervention founded in the principles of motivational psychology and client-centred therapyMultiple components; non-specific techniquesStandard care; routine follow-up appointments202In person (routine HCP)3 sessions of 45–60 min over 3 months
Put et al35Hospital clinic, BelgiumAsthmaBehavioural change intervention involving psycho-education with behavioural and cognitive techniquesMultiple components; non-specific techniquesStandard (no details provided)23In person (researcher)360 min (6×60 min sessions) over 3 months
Remien et al49Community-based clinic, USAHIVCouples-based intervention grounded in social action theoryMultiple components; non-specific techniquesStandard care; education at point of prescribing and follow-up to check adherence and investigate/address underlying causes of any non-adherence196In person (routine HCP)4 sessions of 45–60 min over 5 weeks
Safren et al44Community clinic, USAHIVSingle session minimal treatment intervention using cognitive behavioural, MI and problem solving techniquesMIMinimal contact intervention; daily diary used to record no. of pills prescribed and taken each day53In person (routine HCP)One-off intervention of unknown duration
Sheeran and Orbell28Visits to patient's own home, UKVitamin SupplementsFormation of III via completion of a self-administered questionnaireImplementation Intention Intervention (III)Completion of same questionnaire but without formation of implementation intention78Questionnaire completion (not in person)One-off intervention of unknown duration
Simoni et al48Community-based clinic and telephone calls to patients at home, USAHIVPeer-led medication-related social support interventionMultiple-components; non-specific techniquesStandard care; education programme and social and health referrals as necessary114Group sessions and individual telephone calls (peers)18 sessions of unknown duration over 3 months
Smith et al47Community-based research office, USAHIVSelf-management intervention based on feedback of adherence performance and principles of social cognitive theoryMultiple components; non-specific techniquesStandard care; usual medication counselling, educational leaflets, scheduling support reminder lists and discussion of adherence strategies17In person (routine HCP)Four sessions of unknown duration over 12 weeks
Solomon et al43Telephone calls to patient's own home, USAOsteoporosisTelephone-based counselling programme rooted in MIMIStandard care plus seven information mailings on osteoarthritis care2087Telephone calls (health educator)8 sessions of 14 min over 12 months
Tuldrà et al46Hospital clinic, SpainHIVPsycheducative intervention based on Self-efficacy theoryMultiple components; non-specific techniquesStandard care; normal clinical follow-up77Unknown (routine HCP)7 sessions of unknown duration
van Es et al32Hospital clinic, NetherlandsAsthmaIntervention programme to stimulate a positive attitude, increase social support and enhance self-efficacyMultiple components; non-specific techniquesStandard care; routine check-ups67In person (routine HCP)7 sessions of 30–90 min over 12 months
Wagner et al45Community clinic, USAHIVCognitive behavioural intervention with motivational components, based on the information-motivation-behavioural skills (IMB) modelMultiple components; non-specific techniquesStandard care practices for improving adherence; education, tailoring regimen, offering a pillbox, adherence checks and enquiries about side effects135In person (routine HCP)5 sessions of 30–45 min over 48 weeks
Weber et al33Community, psychotherapy clinic, NetherlandsHIVCognitive behavioural intervention delivered by a psychotherapistMultiple components; non-specific techniquesStandard care (no details provided)53In person (specialist)11 sessions of 45 min over 12 months
Williams et al31Telephone calls and visits to patient's own home, AustraliaDiabetesMultifactorial intervention consisting of self-monitoring of blood pressure, medicine review, educational DVDs and MI to support blood pressure control and optimal medication adherenceMIStandard care (no details provided)75In person and phone calls (specialist)5 sessions, one of 89 min and 4 of an average of 11.75 min, over 3 months