Adherence to cardiovascular medications in the South Asian population: A systematic review of current evidence and future directions

Table 1 Summary of studies included in the systematic review

Ref.	Patient population	Sample size	Country	Design	Adherence measure	Definition of adherence	Adherence rate
Joshi et al[25]	Hypertensive patients seeking treatment	139	India	Cross-sectional	Pill count	≥ 80% pills taken	79% in controlled hypertensives
							39% in uncontrolled hypertensives
Ponnusankar et al[32]	Patients with chronic conditions (hypertension, diabetes mellitus, cardiovascular conditions, bronchial asthma)	90	India	Cross-sectional	Pill count	Prescribed doses taken	92.29% ± 4.5% for counseled group
					Self-assessment	Rating system	84.71% ± 11.8% for usual care
Hashmi et al[12]	Patients prescribed anti-hypertensive medication for at least 1-mo prior	438	Pakistan	Cross-sectional	Pill count	≥ 80% pills taken	Pill count : 77%
					4-item MMAS	≥ 0 scores	Morisky: Mean overall score = 2.5 ± 1.3
Qureshi et al[29]	Patients on anti-hypertensive medications	178	Pakistan	Randomized controlled trial	MEMS bottles	Prescribed doses taken	Intervention arm: 48.1%, 95%CI: 35.8%-60.4%
							Control arm: 32.4%, 95%CI: 22.6%-42.3%
Kar et al[30]	Adults with SBP ≥ 140	1010	India	Cross-sectional	Self-report	All prescribed doses taken daily in the past 15 d	Baseline: 37.9%
							Follow-up: 58.3%
Bahl et al[26]	Adults with hypertension	1175	India	Prospective	Self-report	If all doses were taken since last visit	100% at each follow-up point
Palanisamy et al[31]	Post discharge patients prescribed at least 1 anti-hypertensive medication	43	India	Cross-sectional	4-item MMAS	At least 1 yes response was classified as non-adherent	95.4%
Dennis et al[19]	Hypertensive adults with at least 6 mo treatment history	608	India	Cross-sectional	BMQ	≥ 1 indicates non-adherence	50.33%
Saleem et al[21,22]	Hypertension adults using anti-hypertensive drugs for last 6 mo	385	Pakistan	Cross-sectional	DAI-10	≥ 0 survey scores	Overall mean score: -1.74 ± 2.154
Soliman et al[27]	Adults with an estimated 10-yr total CVD risk score greater than 20%	203	Sri Lanka	Randomized clinical trial	Pill count	Not reported	Intervention arm: Over 80% with > 80% pill compliance
							Usual care arm: Results not provided
Simkhada[16]	Hypertensive patients taking anti-hypertensive medication for at least 6 mo	147	Nepal	Cross-sectional, prospective study	6-item questionnaire	≤ 1 scores	17.34%
Fathima et al[13]	Patients at a CVD clinic	162	India	Cross-sectional	4-item MMAS	≥ 0 scores	Mean score = 3.2
Thom et al[28]	Adults with established CVD, or estimated 5-yr CVD risk ≥ 15%	2004	Europe and India	Randomized clinical trial	Self-report	Taking medication at least 4 d during the week preceding visit	Intervention arm: 86.3%
							Usual care arm: 64.7%
Khanam et al[23]	Randomly selected hypertensive adults from 3 rural surveillance sites	29960	Bangladesh	Cross-sectional	Self-report	Continued medication use at time of interview	73.8%
Kumar et al[15]	Adults on anti-hypertensive medication for more than 6 mo	120	India	Cross-sectional	8-item MMAS	≤ 2 scores	54.2%
					Self-reporting	Not-defined in paper	96.7%
Rao et al[24]	Adults with hypertension and/or diabetes	426	India	Cross-sectional	Self-report	≥ 80% pills taken	Hypertensive 82.2%
							Diabetic 83.6%
Venkatachalam et al[14]	Adults with hypertension for ≥ 1 yr	473	India	Cross-sectional	4-item MMAS	≥ 0 scores	24.1%

MMAS: Morisky medication adherence scale; MEMS: Medication event monitoring system; SBP: Systolic blood pressure; CVD: Cardiovascular disease; BMQ: Brief medication questionnaire; DAI: Drug attitude inventory.