Table 1.

Published studies testing a possible intervention effect of electronic-medication monitoring on typical medication-taking behavior

Author & publication year	Study design	Description of the sample	n	EM	Description of the intervention	Outcome variable: medication adherence or clinical outcome	Result
Wagner et al. 2002	Randomized controlled trial	A community convenience sample of adult HIV-positive patients on HAART	117	MEMS	Experimental group received EM; control group did not	Adherence measured with self-report 4 weeks after study start (% of prescribed pills taken)	Less adherence in the EM group (91%) than in the control group (94%; p=.73)
	Pre-post intervention study	A community convenience sample of adult HIV-positive patients on HAART monitored with EM	60	MEMS	EM started after baseline blood pressure measurement	Adherence measured with self-report at baseline and after 4 weeks	Less adherence after introducing EM (91%) compared to baseline (93%; p=.16)
Bertholet et al. 2000	Pre-post intervention study	A convenience sample of primary care/hypertensive clinic patients with therapy-resistant hypertension	69	MEMS	EM started after baseline blood pressure measurement	Clinical outcome: blood pressure evaluation after 1 – 2 months	Blood pressure was lower after EM (14/9 cm Hg) compared to baseline (16/10 cm Hg; p < .001)
Matsui et al. 1994	Pre-post intervention study	A convenience sample of young β-thalassemia outpatients on a new iron chelator	10	MEMS	The purpose of EM was disclosed to patients after ± 11 months	Adherence measured by EM using the taking adherence parameter ± 18 months after disclosure	Greater adherence after disclosure (84%) compared to before (77%; p=.49)
Yeung et al. 1994	Quasi-experimental study	Non-equivalent study: two convenience samples of asthma patients on inhaling therapy	21	MDI	Intervention group given disclosure; control group not given disclosure	Adherence measured by EM using the taking adherence parameter after 2 – 3 weeks from the study start	Greater adherence in the disclosed group (81%) than in the undisclosed group (71%; p=.53)
Elixhauser et al. 1990	Randomized controlled trial	A convenience sample of psychiatric outpatients treated with lithium	90	Blister package	Experimental group received EM; control group did not	Adherence measured by self-reported, assay, % of expected prescription refills (after 2 – 4 months of study start)	Fewer expected prescription refills in the EM group (18%) than in the control group (31%; p < .01)
Cramer et al. 1990	Observational study	An unspecified sample of patients	24	MEMS	All patients received EM	Adherence measured by EM using the taking adherence parameter during the first and after a mean of 7 months from the start of the study	No difference before and after (79% vs. 79%).