. 2011 Aug 20;26(12):1479–1491. doi: 10.1007/s11606-011-1825-3

Table 1.

Study Characteristics

Source	Patient Population	Sample Size	Country	Rural/ Urban	Design	Adherence Measure	Definition of Adherence	Adherence Rate (%)	Quality Score (%)
Diabetes
Venter, 1991⁶⁵	Randomly selected diabetes clinic patients	68	South Africa	Urban	Cross sectional	Urine test	Drug detected in urine	35	50
Garay-Sevilla, 1995⁷¹	Sample of diabetic patients not previously on treatment at “diabetes clubs”	200	Mexico	Urban	Cross sectional	Self report	Regular medication use	92	88
Kaur, 1998⁷⁴	Diabetic patients in resettlement colony	35	India	Urban	Cross sectional	Self report	Regular medication use	63	13
Khattab, 1999⁷⁵	All registered diabetic patients at a health center	142	Saudi Arabia	Urban	Cohort	Pill Count	Regular medication use	98	11
El-Shazly, 2000⁷⁰	Random selection of diabetic patients with complete health service insurance records	1000	Egypt	Urban	Cross sectional	Self report	…	89	100
Duran, 2001⁶⁹	Adults with type 2 diabetes not taking insulin	150	Mexico	Urban	Cross sectional	Pill Count	≥80% pills taken	54	38
Yousuf, 2001⁷⁸	All eligible hospital patients with diabetes	163	Pakistan	Urban	Cross sectional	Self report	Regular medication use	41	38
Srinivas, 2002⁷⁷	Population-based sample of registered diabetics on medication for >1 year	111	India	Rural	Cross sectional	Self report	No interruption of more than 1 month within the last year	43	50
Hernandez 2003⁷³	Consecutive clinic patients with type 2 diabetes	58	Mexico	Urban	Cross sectional	Pill Count	…	59	50
Cui, 2005⁶⁷	Hospital inpatients with diabetes	144	China	Urban	Cross sectional	Self report	…	74	50
Zhang, 2005⁷⁹	Hospital inpatients with diabetes	176	China	Urban	Cross sectional	Self report	Regular medication use	53	50
Babwah, 2006⁶⁶	Consecutive patients at medical and diabetes clinics	360	Trinidad	Urban	Cross sectional	Self report	Regular medication use	71	75
Duff, 2006⁶⁸	Randomly selected clinic patients with diabetes	86	Jamaica	Urban	Cross sectional	Self report	Regular medication use	45	75
Hanko, 2007⁷²	Patients with diabetes from randomly selected pharmacies	211	Hungary	Mix	Cross sectional	Self report	Regular medication use	53	75
Roaeid, 2007⁷⁶	Diabetes clinic patients with diabetes for >1 year	805	Libya	Urban	Cross sectional	Self report	Regular medication use	73	50
Coronary artery disease
Olubodun, 1990⁸⁹	Hypertensive patients referred to hospital cardiac unit	37	Nigeria	Urban	Cohort	Self report	Regular medication use	0	63
Wiseman, 1991⁹¹	Sample of patients attending cardiac clinic outpatients	137	South Africa	Urban	Cross sectional	Serum drug titers	Serum concentration differs from measured by < 50%	60	38
Chizzola, 1996⁸⁵	Sample from outpatient cardiology referral center	185	Brazil	Urban	Cross sectional	Self report	Regular medication use	41	75
Dantas, 2002⁸⁶	Hospital inpatients who had undergone CABG surgery in the prior 5 months	17	Brazil	Urban	Cohort	Self report	Regular medication use	65	22
Rotchford, 2002⁹⁰	Patients with diabetes presenting for clinic follow up	253	South Africa	Rural	Cross sectional	Self report	Taking medication in previous 24 hours	94	50
El-Gatit, 2003⁸⁷	Clinic patients post aortic valve replacement surgery	62	Libya	Urban	Cohort	MEMS	Regular medication use	93	11
Asefzadeh, 2005⁸⁴	Randomly selected clinic patients with cardiovascular disease	56	Iraq	Urban	Cross sectional	Self report	Regular medication use	59	50
Kocer, 2006⁸⁸	Clinic patients at risk for stroke	612	Turkey	Urban	Cross sectional	Self report	Regular medication use	56	50
Moodley, 2006⁸³	Medical scheme beneficiaries on lipid reducing medications	100,691	South Africa	…	Prospective cohort	Pharmacy claims	…	87	63
Heart failure
Joshi, 1999⁸¹	Consecutive inpatients with congestive heart failure	125	India	Urban	Cross sectional	Pill Count	≥80% pills taken	55	50
Bhagat, 2001⁸⁰	Patients with clinically stable heart failure from 4 general practice clinics	22	Zimbabwe	Urban	Cross sectional	Self report	Regular medication use and knowledge	73	38
Sadik, 2005⁸²	Hospital in- and outpatients with heart failure	208	UAE	Urban	Randomized controlled trial	Self report	Regular medication use	33	60
Hypertension
Buchanan, 1979²³	Sample of black diabetic and hypertensive clinic patients	100	South Africa	Urban	Cohort	Home visits	≥85% pills taken	38	75
Unterhalter1979⁵⁵	Sample of black diabetic clinic patients	50	South Africa	Urban	Cross sectional	Pill Count	≥85% pills taken	38	50
Supramaniam, 1982⁵⁴	Random sample of armed force personnel with hypertension	102	Malaysia	Rural	Cross sectional	Self report, visit records	…	41	25
Marshall, 1988⁴³	Random sample of women not previously receiving treatment	88	South Africa	Rural	Cross sectional	Self report	Regular medication use	73	0
Roy, 1990⁴⁸	Hospital inpatients with hypertension who had a prior stroke	66	Bangladesh	Urban	Cohort	Self report	Regular medication use	12	22
Stein, 1990⁵³	Sample of hypertension clinic patients	18	Zimbabwe	Urban	Open cross-over	Pill Count	Correct number of pills returned	97	75
Saunders, 1991⁵¹	Consecutive clinic patients with hypertension	20	South Africa	Urban	Randomized controlled trial	Pill count	≥80% pills taken	15	20
Lim, 1992³⁹	Consecutive hospital outpatients with hypertension	168	Malaysia	Urban	Cohort	Pill count, self report	≥80% pills taken	74	63
Hungerbuhler, 1995³⁴	Consecutive clinic patients with uncontrolled hypertension	187	Seychelles	…	Cohort	Urine test	Pills taken “concordant” with pills prescribed	56	50
Joshi, 1996³⁵	Consecutive new clinic patients with hypertension	139	India	Urban	Cohort	Pill Count	≥80% pills taken	66	63
Khalil, 1997⁶²	Random sample of health centers patients with hypertension	347	Saudi Arabia	Urban	Cohort	Pill Count	≥80% pills taken	47	63
Maro, 1997⁴²	Cardiac clinic patients starting antihypertensive treatment	146	Tanzania	Urban	Cohort	Self report or pill count	≥75% pills taken	90	44
Lunt, 1998⁴¹	Community health center patients with hypertension	889	South Africa	Urban	Cohort	Drug pick up	Collected drugs on ≥ 75% of visits	77	33
Salome Kruger, 1998⁵⁰	Outpatients attending clinic for at least 1 year	132	South Africa	Urban	Cross sectional	Self report	Regular medication use	38	50
Zdrojewski, 1999⁶⁰	Elderly patients with hypertension	198	Poland	…	Cross sectional	Self report	Regular medication use	71	50
Elzubier, 2000²⁹	Consecutive clinic patients with hypertension	198	Sudan	Urban	Cross sectional	Pill Count	≥80% pills taken	60	75
Bovet, 2002²¹	Random sample of patients with sustained hypertension	50	Seychelles	Rural	Cohort	MEMS	≥86% pills taken	46	44
Jiang, 2002⁶¹	Clinic patients with hypertension from general hospitals in 8 cities	4510	China	Urban	Cross sectional	Self report	…	44	38
Youssef, 2002⁵⁷	Random selection of hypertensive patients at health insurance clinics	316	Egypt	Urban	Cross sectional	Records, self report	≥90% pills taken	74	50
Bharucha, 2003²⁰	Random population sample of patients with hypertension	453	India	Urban	Cross sectional	Self report	…	64	38
Li, 2003³⁸	Clinic patients with hypertension from 8 cities	3112	China	Urban	Cross sectional	Self report	Regular medication use	44	75
Salako, 2003⁴⁹	Consecutive clinic patients with hypertension	422	Nigeria	Urban	Cross sectional	Self report	…	80	25
Buabeng, 2004²²	All new clinic patients with hypertension	128	Ghana	Urban	Cross sectional	Self report	≥80% pills taken	7	38
Chen, 2004²⁵	Sample of patients with hypertension on medication	312	China	Urban	Cross sectional	Self report	Regular medication use	43	50
Hadi, 2004³²	All eligible patients with hypertension who attended clinic consultation	250	Iran	Urban	Cross sectional	Self report	≥90% pills taken	40	100
Lu, 2004⁴⁰	Sample of patients with hypertension	1831	China	Urban	Cross sectional	…	…	74	63
Naddaf, 2004⁴⁴	Randomly selected clinic patients with hypertension	100	Jordan	Urban	Cross sectional	Self report	No missed doses in prior 30 days	58	38
Peltzer, 2004⁴⁶	Consecutive clinic patients with hypertension for >1 year	100	South Africa	Mix	Cross sectional	Self report	Regular medication use	65	75
Sookaneknun, 2004⁵²	Pharmacy and primary care patients with hypertension	217	Thailand	Mix	Randomized controlled trial	Pill Count	≥80% pills taken	61	49
Akpa, 2005¹⁶	Consecutive cardiology clinic patients with hypertension	100	Nigeria	Urban	Cross sectional	Self report	≥75% pills taken	60	25
Coelho, 2005²⁶	Randomly selected clinic patients with hypertension	245	Brazil	Urban	Cohort	Self report	…	87	22
Feng, 2005³⁰	Hospital inpatients with essential hypertension	164	China	Urban	Cross sectional	Self report	Regular medication use	65	75
Fodor, 2005³¹	All hypertensive employees at workplace	359	Austria, Hungary, Slovakia	Urban	Cross sectional	Self report	Regular medication use	54	75
Xiao, 2005⁵⁶	Hospital inpatients with hypertension	119	China	Urban	Cross sectional	Self report	…	41	50
Yusuff, 2005⁵⁹	Clinic outpatients presenting with hypertension	200	Nigeria	…	Cohort	Record	Regular medication use	83	44
Almas, 2006¹⁷	Outpatients with hypertension	200	Pakistan	Urban	Cross sectional	Self report	Did not miss dose for 6 months	57	63
Ben Abdelaziz, 2006¹⁹	Representative sample of hypertensive patients in regional health care facilities	292	Tunisia	Urban	Cross sectional	Healthcare assessment	Pharmacy contacts	59	38
Hassan, 2006³³	Clinic patients with hypertension on medications for at least 3 months	242	Malaysia	Urban	Cross sectional	Self report	≥80% pills taken	44	100
Lambert, 2006³⁷	Convenience sample of hypertension clinic patients	98	South Africa	Urban	Cross sectional	Self report	Regular medication use	24	63
Amira, 2007¹⁸	Consecutive clinic patients with hypertension	225	Nigeria	Urban	Cross sectional	Self report	Regular medication use	65	75
Castro, 2007²⁴	Consecutive patients with hypertension from a family health program	66	Brazil	Urban	Cross sectional	Self report	Regular medication use	67	63
de Souza, 2007²⁷	Consecutive patients at a cardiovascular pharmacology clinic	48	Brazil	Urban	Cohort	Pill count	≥80% pills taken	64	44
Dennison, 2007²⁸	Black patients with hypertension at local primary care clinics	403	South Africa	Urban	Cross sectional	Self report	…	48	88
Konin, 2007³⁶	Consecutive clinic patients who were hypertensive	200	Ivory Coast	Urban	Cross sectional	Self report	…	13	50
Prado, 2007⁶⁴	Random sample of health center patients with mild to moderate hypertension	120	Brazil	Urban	Cross sectional	Pill count	≥80% pills taken	38	75
Qureshi, 2007⁴⁷	Patients in the control arm of a hypertension health education trial	100	Pakistan	Urban	Randomized controlled trial	MEMS	Regular medication use	48	60
Yusuff, 2007⁵⁸	Random sample of hypertension clinic patients	400	Nigeria	Urban	Cross sectional	Healthcare assessment	…	49	63
Nugmanova, 2008⁴⁵	Sample of patients with hypertension	227	Kazakhstan	Urban	Randomized controlled trial	Self report	Medication taken on the morning of interview	38	40