Table 1.
Summary of randomized controlled intervention studies assessing medication adherence and health outcomes in older adults
| Study | Number of participants | Intervention | Duration of intervention and measurement period | Results |
|---|---|---|---|---|
| Behavioral/educational interventions | ||||
| Daley et al. [18] | 38 intervention, 38 control participants with treated idiopathic Parkinson’s disease | ‘Adherence therapy’—a brief, cognitive–behavioral approach aimed at facilitating a process of shared decision-making | Intervention delivered as 7 weekly one-to-one sessions in the participants’ home Outcomes assessed at baseline and 12 weeks |
Intervention improved self-reported adherence (via 4-item MMAS) vs. control (OR 8.2, 95% CI 2.8–24.3) Intervention improved quality of life as measured by the Parkinson’s Disease Questionnaire-39 (–9.0, 95% CI –12.2 to –5.8) |
| Goeman et al. [19] | 58 intervention, 56 control participants with asthma | Patient Asthma Concerns Tool (PACT), an instrument to tailor education to improve asthma-related health literacy and address patient concerns and unmet needs | 1-h face-to-face intervention delivered at baseline, 3 months, and 12 months Outcomes assessed at baseline, 3 months, and 12 months |
Intervention group had significant improvements in adherence (via electronic inhaler monitors) to preventer medication (increase from baseline to 12 months, 19.3%, 95% CI 6.9–31.6) compared with a non-significant increase in control group (7.2%, 95% CI −5.1 to 19.5) Intervention group had better self-reported asthma control than that of the control group at both 3 (p = 0.02) and 12 months (p < 0.001) |
| Solomon et al. [20] | 1046 intervention, 1041 control participants with osteoporosis | Telephone-delivered motivational interviewing sessions by a trained health educator | Median of 8 telephone sessions averaging 14 min delivered 1–2 times per month Outcomes assessed at 12 months of follow-up |
No difference (p = 0.07) in medication adherence (via medication possession ratio) in intervention group (49%) vs. the control group (41%) No differences (p > 0.05) in self-reported secondary outcomes of fractures (intervention vs. control 10.9 vs. 11.2%) |
| Pharmacist-led interventions | ||||
| Al-Rashed et al. [21] (2002) | 43 intervention, 40 control participants with polypharmacy (prescribed ≥4 medications) | Inpatient pharmaceutical counseling, linked to a medication and information discharge summary and a medicine reminder card | One-time intervention delivered prior to discharge from hospital to home Outcomes assessed post-discharge at 2–3 weeks (visit 1) and 3 months (visit 2) |
Medication adherence (via pill counts) significantly improved in intervention vs. control group (p < 0.001) at both follow-ups Fewer unplanned visits to the general practitioner in intervention vs. control group at both follow-ups (p < 0.05) Fewer readmissions to hospital in intervention vs. control group at both follow-ups (p < 0.05) |
| Lipton and Bird [22] | 350 intervention, 356 control participants with polypharmacy (prescribed ≥3 long-term medications) | Pharmacist consultation at hospital discharge to discuss the purpose and use of their medications and potential drug-related problems, in collaboration with the patient’s physician | Intervention delivered at time of hospital discharge and again at 1 week, 2–4 weeks, 2 months, and 3 months post-discharge Medication adherence outcomes assessed among a sub-sample at 6–8 weeks and again at 12–14 weeks post-discharge; healthcare utilization outcomes assessed at 1, 3, and 6 months |
Medication adherence (via self-reported telephone survey) was significantly higher at the first assessment in the intervention than the. control group (mean score 94.4 vs. 91.4; p = 0.04) as well as at the second assessment (96.3 vs. 91.2, p < 0.001) No between-group differences in healthcare utilization over 6 months (p > 0.05) |
| Murray et al. [23] | 122 intervention, 192 control participants with heart failure in outpatient setting | Pharmacy-based program to support medication adherence and management using a clinical protocol, patient-friendly icons on dispensed prescription vials indicating medication class, and verbal/written instructions | Intervention delivered at time of dispensing for 9 months; patients came for refills at approximately 2-month intervals Outcomes assessed at 12 months |
Medication adherence measured by electronic monitors was greater during the intervention period for patients receiving the interventions compared with control (78.8 vs. 67.9%; difference 10.9%, 95% CI 5.0–16.7); this effect dissipated in the 3-month post-intervention phase Medication adherence measured by refill data was greater in intervention group than in controls (p = 0.007) Self-reported adherence was not significantly different between groups (p = 0.48) Exacerbations requiring emergency department visit or hospitalization were fewer in the intervention group than in controls (incidence rate ratio 0.82, 95% CI 0.73–0.93) |
| Nazareth et al. [24] | 181 intervention, 181 control participants with polypharmacy (≥4 medications) | Pharmacist consultation at hospital discharge and within 2 weeks after discharge, which could include practical assistance (e.g., dispensing in non-child-proof vials, large-print labels) | Intervention delivered at 2 timepoints Outcomes assessed at baseline, 3 and 6 months |
No between-group differences in self-reported medication adherence (p > 0.05) No between-group differences in hospital readmissions at 6 months (p > 0.05) |
| Olesen et al. [25] | 315 intervention, 315 control participants with polypharmacy (≥5 medications) | Pharmaceutical care aimed at identifying, resolving, and preventing drug-related problems | In-person baseline assessment followed by 3 intervention telephone calls Outcomes assessed at 3, 6, and 9 months |
No significant improvement in medication adherence (via pill counts) (OR 1.14, 95% CI 0.65–2.00) No differences in hospitalization and death (p > 0.05) |
| Wu et al. [26] (2006) | 219 intervention, 223 control participants with polypharmacy (≥5 medications) | Pharmacist consultation between clinic visits focused on explaining misconceptions and encouraging adherence and healthy habits | 6–8 telephone calls and 1 in-person intervention delivered over a 2-year study period Outcomes assessed at baseline and 2 years |
Among those non-adherent at baseline (measured by pharmacy refills), 93% of intervention group and 82% of control group were adherent by end of study (p < 0.001) Mortality was less in the intervention than the control group (relative risk 0.59, 95% CI 0.35–0.97) |
| Volume et al. [27] (2001) | 5 intervention (pharmacies) including 159 patients, 7 control (pharmacies) including 204 patients, all with polypharmacy (≥3 medications) | Pharmacist’s Management of Drug-Related Problems instrument to foster pharmaceutical care | Intervention at time of dispensing delivered for 12 months Outcomes assessed at baseline, 6–7 months, and 12–13 months |
Self-reported medication adherence (via 4-item MMAS) not significantly impacted by the intervention (p > 0.05) Health-related quality of life not significantly impacted by the intervention (p > 0.05) |
| Reminder/simplification interventions | ||||
| Fulmer et al. [28] | 15 telephone call group; 17 videotelephone call group; 18 control group participants with heart failure | A telephone or videotelephone call made daily by nurse, where patients were asked whether they had taken their medications the previous day | Daily intervention delivered for 6 weeks Outcomes assessed at baseline and 10 weeks |
By week 10, adherence (via electronic monitoring) was significantly worse for control group (81–57%) compared with adherence for either telephone (76–74%) or videotelephone (82 to 84%) (p <0.05) No significant change in generic (SF-36) or disease-specific quality of life |
| Schneider et al. [29] (2008) | 47 intervention, 38 control participants with hypertension | Use of a 28-day blister calendar pack for hypertensive outpatients prescribed the ACE inhibitor lisinopril compared with usual loose-table medication containers | Intervention delivered for 12 months Adherence outcome assessed over 12 months; other outcomes assessment at baseline, 6 months, and 12 months |
Percentage on-time refills were greater in intervention group than in controls (80.4 ± 21 vs. 66.1 ± 28.0; p = 0.01) Medication possession ratio was greater in the intervention group than in controls (0.93 ± 11.4 vs. 0.87 ± 14.2; p = 0.04) Effects on cardiovascular events and healthcare utilization were not significant (p > 0.05) |
CI confidence interval, MMAS Morisky Medication Adherence Scale, OR odds ratio