Original Research ARTICLE
Development and validation of a novel General Medication Adherence Scale (GMAS) for chronic illness patients in Pakistan
- 1School of Pharmaceutical Sciences, University of Science, Malaysia, Malaysia
- 2DOW College of Pharmacy, DOW University of Health Sciences (DUHS), Pakistan
- 3Department of Clinical Pharmacy, College of Pharmacy, Umm Al Qura University, Saudi Arabia
- 4Department of Pharmacy Practice, International Islamic University Malaysia, Malaysia
Objective: This study aimed to develop and validate a self-reporting adherence tool termed as General Medication Adherence Scale (GMAS) in Urdu language for measuring adherence towards medication use among Pakistani patients with a chronic disease.
Methods: A month-long study (December 2017) was conducted in three tertiary health care settings of Karachi, Pakistan. The tool underwent content and face validity as well as factor analyses i.e., exploratory, partial confirmatory and confirmatory factor analyses. Random sampling was conducted, and sample size was calculated using item response theory. The item-to-respondent ratio was 1:15. Fit indices namely normed fit index (NFI), Tucker Lewis index (TLI), comparative fit index (CFI), goodness of fit index (GFI), absolute goodness of fit (AGFI), parsimony goodness of fit index (PGFI), root mean square error of approximation (RMSEA) and standard root mean square residual (SRMR) were calculated. Additionally, estimation of the convergent, discriminant and known group validities, was conducted. Internal consistency was analysed by test-retest reliability, McDonald’s and Pearson correlation coefficient. The factor analyses were conducted using IBM SPSS version 22 and IBM SPSS AMOS version 25.
Results: Content validity index (CVI) was reported at 0.8 (SD 0.147) and the tool was content validated with three hypothetical constructs. Factor analyses highlighted a 3-factor structure. The fit indices were calculated with satisfactory results, i.e., PGFI, GFI, AGFI, NFI, TLI and CFI were greater than 0.9 and PGFI >0.5. The values of RMSEA and SRMR were less than 0.07. A Cronbach’s alpha value of 0.84 was obtained in reliability analysis. The test-retest Pearson’s correlation coefficient value was reported at 0.996 (p-value<0.01). Convergent and discriminant validities for all constructs and, known group validity for two constructs, were established. A high response rate of 91% was achieved in respondents. Patients without insurance coverage appeared to be low adherent compared to those with insurance coverage (p-value<0.05). Non-comorbid patients were more likely to be highly adherent as compared to comorbid patients (p-value<0.01).
Conclusion: A novel tool GMAS was developed in Urdu language and was subsequently validated in patients with chronic diseases.
Keywords: Medication Adherence, Chronic Disease, social pharmacy, Pakistan, patient adherence, Patient Compliance, medication persistence
Received: 25 Dec 2017;
Accepted: 13 Sep 2018.
Edited by:Heike Wulff, University of California, Davis, United States
Reviewed by:Dominique J. Dubois, Free University of Brussels, Belgium
Domenico Criscuolo, Genovax S.r.l., Italy
Copyright: © 2018 Naqvi, Hassali, Rizvi, Zehra, Iffat, Haseeb and Jamshed. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: Mr. Atta A. Naqvi, University of Science, Malaysia, School of Pharmaceutical Sciences, George Town, 11800, Penang, Malaysia, email@example.com