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

  • Caroline A. WalshEmail author
  • Caitriona Cahir
  • Kathleen E. Bennett
Pharmacoepidemiology and Prescription



To examine the association between antihypertensive medication (AHTM) implementation adherence and healthcare utilisation in community-dwelling adults aged ≥ 50 years in Ireland.


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).


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.


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.


Medication adherence Hospitalisation Health outcomes Older 



The authors wish to thank TILDA staff at Trinity College Dublin and staff at the HSE-PCRS for collecting and providing the authors with the data used in this study.

Authors’ individual contributions

CW, CC and KB were involved in the concept and design of the study. Data was provided by TILDA and the HSE-PCRS. CW carried out the statistical analysis. All authors were involved in interpretation of the data. CW wrote the first draft of the manuscript and all authors contributed to subsequent drafts.


CW, CC and KB were funded by the Health Research Board (HRB), Research Leaders Award (HRB RL-2015-1579). This work was conducted as part of the SPHeRE Programme under Grant No. SPHeRE/2013/1. TILDA is supported by the Department of Health and Children, The Atlantic Philanthropies and Irish Life.

Compliance with ethical standards

Ethical approval

Ethical approval for each wave of TILDA was obtained from the Trinity College Research Ethics Committee. Provision was made within this application to allow for the linking of participants GMS dispensing data, subject to participants’ consent.


The funding bodies had no role in this study design, data analysis, writing of the manuscript or the decision to submit for publication.

Supplementary material

228_2019_2699_MOESM1_ESM.pdf (259 kb)
Supplementary Table 1 (PDF 259 kb)
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Supplementary Table 2 (PDF 275 kb)
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Supplementary Table 3 (PDF 278 kb)
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Supplementary Table 4 (PDF 276 kb)
228_2019_2699_MOESM5_ESM.pdf (277 kb)
Supplementary Table 5 (PDF 276 kb)


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Copyright information

© Springer-Verlag GmbH Germany, part of Springer Nature 2019

Authors and Affiliations

  1. 1.Division of Population Health Sciences, Beaux Lane HouseRoyal College of Surgeons in IrelandDublin 2Ireland
  2. 2.Department of Pharmacology and Therapeutics, Trinity College Dublin, Trinity Health Centre for Health SciencesSt. James’s HospitalDublinIreland

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