Table 2.

Pooled estimates

Study and study location	Prescribed medication class	Number of study prescriptions	Primary nonadherence rate (%)	95% CI
Aznar-Lou et al;26 2017, Spain	Hypoglycemics	8,270	13.2	12.5–14.0
	Antihypertensives	74,346	7.5	7.3–7.7
	Lipid-lowering	69,602	8.8	8.6–9.0
	Antidepressants	97,635	11.5	11.3–11.7
Bauer et al;15 2014, USA	Antidepressants	1,523	4.3	3.3–5.4
Casebeer et al;27 2009, USA	Lipid-lowering	913	43.2	39.9–46.4
Chan et al;3 2004, Canada	Antihypertensives	1,700	33.5	31.3–35.8
	Lipid-lowering	1,700	71.0	68.8–73.1
Cheetham et al;28 2013, USA	Lipid-lowering	19,826	15.4	14.9–15.9
Derose et al;29 2013, USA	Lipid-lowering	5,216	18.4	17.4–19.5
Ewen et al;30 2015, Germany	Antihypertensives	100	2.0	0.2–7.0
Fischer et al;31 2015, USA	Hypoglycemics	346	6.4	4.0–9.5
	Antihypertensives	2,065	3.3	2.6–4.2
	Lipid-lowering	528	6.4	4.5–8.9
Fischer et al;12 2010, USA	Hypoglycemics	5,525	21.9	20.8–23.0
	Antihypertensives	30,211	19.5	19.0–19.9
	Lipid-lowering	12,963	19.9	19.2–20.6
	Antidepressants	11,767	21.4	20.6–22.1
Freccero et al;32 2016, Sweden	Antidepressants	11,624	14.9	14.3–15.6
van Geffen et al;33 2009, the Netherland	Antidepressants	965	4.3	3.1–5.7
Jackevicius et al;34 2008, Canada	Hypoglycemics	146	13.7	8.6–20.4
	Antihypertensives	5,337	6.4	5.8–7.1
	Lipid-lowering	758	5.2	3.7–7.0
	Antidepressants	43	32.6	19.1–48.5
Karter et al;35 2009, USA	Hypoglycemics	8,191	4.0	3.6–4.5
	Antihypertensives	12,712	3.2	2.9–3.5
	Lipid-lowering	6,426	8.5	7.8–9.2
Kerner et al;36 2017, USA	Antihypertensives	9	22.2	2.8–60.0
Linnet et al;19 2012, Iceland	Hypoglycemics	760	8.7	6.8–10.9
	Antihypertensives	4,127	8.6	7.7–9.5
	Antidepressants	4,492	6.6	5.9–7.4
O’Connor et al;37 2014, USA	Hypoglycemics	2,378	13.3	11.9–14.7
Raebel et al;25 2012, USA	Hypoglycemics	1,521	11.3	9.8–13.0
	Antihypertensives	4,721	7.0	6.3–7.8
	Lipid-lowering	4,607	12.6	11.6–13.6
Shah et al;38 2008, USA	Hypoglycemics	1,132	15	13.0–17.2
Shah et al;39 2009, USA	Antihypertensives	3,240	17.1	15.8–18.5
Shin et al;16 2012, USA	Hypoglycemics	14,417	12.6	12.0–13.1
	Antihypertensives	48,982	7.8	7.5–8.0
	Lipid-lowering	22,249	22.3	21.8–22.9
	Antidepressants	27,383	7.7	7.4–8.0
Tamblyn et al;40 2014, Canada	Hypoglycemics	979	29.1	26.3–32.1
	Antihypertensives	3,108	32.2	30.5–33.8
	Lipid-lowering	2,794	33.6	31.9–35.4
Thengilsdóttir et al;14 2015, Iceland	Lipid-lowering	2,132	6.2	5.2–7.3
	Antidepressants	8,553	8.0	7.4–8.6
Trinacty et al;41 2009, USA	Hypoglycemics	1,906	10.0	8.7–11.5
Xing et al;42 2011, USA	Antidepressants	557	13.1	10.4–16.2
Pooled random estimate		550,485	14.6	13.1–16.2