Longitudinal Medication Adherence in Older Adults With Multimorbidity and Association With Health Care Utilization: Results From the Irish Longitudinal Study on Ageing.

BACKGROUND: The association between objectively measured nonadherence and health care utilization in multimorbid older people is unclear. OBJECTIVE: To measure medication adherence across multiple chronic conditions, identify adherence patterns, and estimate the association between adherence and self-reported health care utilization. METHODS: This is a retrospective cohort study of multimorbid participants aged ≥70 years in the Irish LongituDinal Study on Ageing (TILDA). Eligible participants had linked pharmacy claims data and completed TILDA wave 2 (2 years after wave 1). The RxRisk-V tool was used to identify multimorbidity. Average adherence (AA) across RxRisk-V conditions was estimated using the CMA7 function (AdhereR). Group-based trajectory models (GBTMs) identified adherence patterns in the 12 months following wave 1. Negative binomial regression was used to estimate the association between adherence and the rate of subsequent self-reported general practitioner [GP] visits, emergency department (ED) visits, outpatient visits, and hospitalizations in the 12 months following adherence measurement (reported at wave 2). Adjusted Incident Rate Ratios (aIRR) and 95% CIs are presented. RESULTS: Higher AA (CMA7) was associated with a small significant decrease in GP visit rate (aIRR = 0.70; CI = 0.53-0.94) and outpatient visit rate (aIRR = 0.44; CI = 0.23-0.81). GBTM identified 6 adherence groups (n = 1050). Compared with high adherers, group 1 (rapid decline, modest increase) membership (aIRR = 1.72; CI = 1.09-2.73) and group 4 (high adherence, delayed decline) membership (aIRR = 1.92; CI = 1.19-3.05) significantly increased ED visit rate. CONCLUSION AND RELEVANCE: Suboptimal medication adherence in multimorbid older adults is associated with increased health care utilization. Identification of suboptimal adherence groups for medication management interventions may help decrease the health system burden and health care costs.

Identifying Adherence Patterns Across Multiple Medications and Their Association With Health Outcomes in Older Community-Dwelling Adults With Multimorbidity.

OBJECTIVES: To classify older people with multimorbidity according to their adherence patterns and to examine the association between medication adherence and health outcomes. METHODS: This is a secondary analysis of a cohort study. Community-dwelling adults aged ≥70 years were recruited from 15 general practices in Ireland in 2010 (wave 1) and followed up 2 years later (wave 2). Participants had ≥2 RxRisk-V multimorbidity conditions at wave 1 and had ≥2 dispensations of RxRisk-V medications (wave 1-wave 2). Average adherence across RxRisk-V conditions was estimated based on continuous multiple-interval measure of medication availability (CMA7 function in AdhereR). Group-based trajectory models were used to group participants' adherence patterns for RxRisk-V medications. Multilevel regression was used to examine the association between adherence and (1) EuroQol 5-dimension (EQ-5D) utility (linear) and (2) vulnerability, using the Vulnerable Elders Survey (≥3 defined as vulnerable; logistic) at wave 2, controlling for potential confounders. RESULTS: Average adherence (CMA7) was 77% across 501 participants. Group-based trajectory models identified 5 adherence groups: (1) initial low adherers, gradual increase; (2) high adherers, sharp decline; (3) steady adherers, gradual decline; (4) consistent high adherers; and (5) consistent nonadherers. Higher average adherence was associated with a significant increase in EQ-5D utility (adjusted ß = 0.11, robust standard error 0.04). Group 5 was associated with significantly increased vulnerability compared to group 4 (adjusted odds ratio = 1.88; 95% confidence interval 1.01-3.50). CONCLUSION: Increased average adherence was associated with higher EQ-5D utility. Adherence grouping did not significantly impact utility. Suboptimal adherence to multiple medications in older adults with multimorbidity was associated with vulnerability.

Mapping the use of Group-Based Trajectory Modelling in medication adherence research: A scoping review protocol.

The use of group-based trajectory modelling (GBTM) within the medication adherence literature is rapidly growing. Researchers are adopting enhanced methods to analyse and visualise dynamic behaviours, such as medication adherence, within 'real-world' populations. Application of GBTM based on longitudinal adherence behaviour allows for the identification of adherence trajectories or groups.  A group is conceptually thought of a collection of individuals who follow a similar pattern of adherence behaviour over a period of time. A common obstacle faced by researchers when implementing GBTM is deciding on the number of trajectory groups that may exist within a population. Decision-making can introduce subjectivity, as there is no 'gold standard' for model selection criteria. This study aims to examine the extent and nature of existing evidence on the application of GBTM for medication adherence assessment, providing an overview of the different GBTM techniques used in the literature. The methodological framework will consist of five stages: i) identify the research question(s); ii) identify relevant studies; iii) select studies; iv) chart the data and finally, v) collate, summarise and report the results. Original peer-reviewed articles, published in English, describing observational and interventional studies including both concepts and/or sub-concepts of GBTM and medication adherence or any other similar terms, will be included. The following databases will be queried: PubMed/MEDLINE; Embase (Ovid); SCOPUS; ISI Web of Science and PsychInfo. This scoping review will utilise the PRISMA extension for Scoping Reviews (PRISMA-ScR) tool to report results. This scoping review will collect and schematise different techniques in the application of GBTM for medication adherence assessment available in the literature to date, identifying research and knowledge gaps in this area. This review can represent an important tool for future research, providing methodological support to researchers carrying out a group-based trajectory analysis to assess medication adherence in a real-world context.

The association between medication non-adherence and adverse health outcomes in ageing populations: A systematic review and meta-analysis.

AIMS: The aim of this systematic review and meta-analysis was to synthesise the evidence relating to medication non-adherence and its association with health outcomes in people aged ≥50 years. METHODS: Seven databases were searched up to February 2019 for observational studies that measured medication (non-)adherence as a predictor of the following health outcomes in adults aged ≥50 years: healthcare utilisation (hospitalisation, emergency department visits, outpatient visits and general practitioner visits), mortality, adverse clinical events and quality of life. Screening and quality assessment using validated criteria were completed by 2 reviewers independently. Random effects models were used to generate pooled estimates of association using adjusted study results. The full methodological approach was published on PROSPERO (ID: CRD42017077264). RESULTS: Sixty-six studies were identified for qualitative synthesis, with 11 of these studies eligible for meta-analyses. A meta-analysis including 3 studies measuring medication non-adherence in adults aged ≥55 years showed a significant association with all-cause hospitalisation (adjusted odds ratio 1.17, 95% confidence interval [CI] 1.12, 1.21). A meta-analysis including 2 studies showed that medication non-adherence was not significantly associated with an emergency department visit (adjusted odds ratio 1.05, 95% CI 0.90, 1.22). Good adherence was associated with a 21% reduction in long-term mortality risk in comparison to medication non-adherence (adjusted hazard ratio 0.79, 95% CI 0.63, 0.98). CONCLUSION: Medication non-adherence may be significantly associated with all-cause hospitalisation and mortality in older people. Medication adherence should be monitored and addressed in this cohort to minimise hospitalisation, improve clinical outcomes and reduce healthcare costs.

Association between adherence to antihypertensive medications and health outcomes in middle and older aged community dwelling adults; results from the Irish longitudinal study on ageing.

PURPOSE: To examine the association between antihypertensive medication (AHTM) implementation adherence and healthcare utilisation in community-dwelling adults aged ≥ 50 years in Ireland. METHODS: This was a prospective cohort study. The Irish Longitudinal Study on Ageing (TILDA) was linked to pharmacy claims data for participants aged ≥ 50 years. Participants were included if they had ≥ 3 pharmacy claims for one or more AHTM (ATC codes 'C02', 'C03', 'C07', 'C08' or 'C09') within the year preceding the year of self-reported healthcare utilisation outcome occurrence. Outcomes included self-reported general practitioner (GP), emergency department (ED), outpatient department visits and hospital admissions. Implementation adherence was measured using proportion of days covered (PDC), with participants classified as adherent if the average PDC ≥ 0.8. Negative binomial models were used to analyse the association between AHTM adherence and number of GP, ED, outpatient visits and hospitalisations (adjusted IRR and 95% CI are presented). RESULTS: One thousand four hundred thirty-one participants were included. The majority of participants (72.6%) were considered adherent. Good implementation adherence to AHTM was associated with a significant decrease in self-reported GP visits (adjusted IRR 0.91, 95% CI 0.83-0.99). Adherence had no significant impact on the number of ED visits, outpatient visits or hospitalisations reported by TILDA participants. CONCLUSIONS: Good adherence to AHTM was associated with less self-reported GP visits in this population, suggesting improved overall health status. However, the impact of medication non-adherence on the other self-reported healthcare utilisation outcomes (ED, outpatient visits and hospitalisations) was not evident in this study.