The influence of symptoms of anxiety and depression on medication nonadherence and its causes: a population based survey of prescription drug users in Sweden

Figures & data

Table 1 Number of participants in the study population, including prescription drug usersa and nonadherentb prescription drug users, by sex and age

Age (years)	Men			Women
	Number in study population	Number of users (% of total)	Number of nonadherent users (% of users)	Number in study population	Number of users (% of total)	Number of nonadherent users (% of users)
18–34	452	107 (23.7)	78 (72.9)	610	369 (60.5)	287 (77.8)
35–44	363	128 (35.3)	105 (82.0)	466	264 (56.7)	212 (80.3)
45–54	388	173 (44.6)	121 (69.9)	442	264 (59.7)	201 (76.1)
55–64	456	287 (62.9)	201 (70.0)	472	352 (74.6)	226 (64.2)
65–74	319	235 (73.7)	128 (54.5)	337	272 (80.7)	138 (50.7)
75–84	182	154 (84.6)	76 (49.4)	222	197 (88.7)	87 (44.2)
Total	2,160	1,084 (50.2)	709 (65.4)	2,549	1,718 (67.4)	1,151 (67.0)

Notes:

a Drug users were defined as participants who reported use of one or more prescription drug during the two weeks before receiving the questionnaire;

b nonadherent drug users were defined as participants who responded positively to any of the nonadherent behaviors in the questionnaire (forgot to take the medication, filled prescription but did not use medication, changed dosage on own accord, discontinued a medical treatment, did not fill prescription).

Table 2 Percentages of prescription drug users with or without symptoms of anxiety and/or depression who reported various types of nonadherent behavior

Nonadherent behaviora	Men n = 702				Women n = 1,138				All n = 1,840
	Anx n = 76	Depr n = 34	Both n = 68	None n = 524	Anx n = 159	Depr n = 49	Both n = 121	None n = 809	Anx n = 235	Depr n = 83	Both n = 189	None n = 1,333
Any nonadherence (unintentional or intentional)	81.7	64.2	81.9	62.2	75.4	83.1	79.1	63.7	77.3	74.1	80.1	63.1
Unintentional nonadherence (forgot to take the medication)	64.5	49.1	73.5	48.3	57.3	64.4	57.5	46.2	59.5	57.1	63.1	47.1
Any intentional nonadherence (see below)	58.1	47.2	60.2	38.0	57.3	67.8	64.7	43.6	57.6	58.0	63.1	41.4
Changed dosage on own accord	33.3	22.6	38.6	18.5	25.6	32.2	29.4	13.4	28.0	27.7	32.6	15.4
Discontinued a medical treatment	33.3	18.9	26.5	17.3	31.3	37.3	29.4	21.7	31.9	28.6	28.4	19.9
Filled a prescription but did not take the medication	30.1	22.6	20.5	17.6	35.6	35.6	31.4	23.9	33.9	29.5	27.5	21.4
Did not have a prescription filled	22.6	28.3	31.3	15.3	29.4	33.9	39.9	19.3	27.3	31.2	36.9	17.7

Notes: Missing values, men n = 7, women n = 13.

a Several choices could be made by the same participant.

Abbreviations: Anx, anxiety; Depr, depression.

Table 3 Percentages of prescription drug users with or without symptoms of anxiety and/or depression who gave various reasonsa for nonadherence

Reasons for nonadherence	Men n = 702				Women n = 1,138				All n = 1,840
	Anx n = 76	Depr n = 34	Both n = 68	None n = 524	Anx n = 159	Depr n = 49	Both n = 121	None n = 809	Anx n = 235	Depr n = 83	Both n = 189	None n = 1,333
Did not need the medication	17.2	11.3	13.3	12.2	16.6	15.3	15.0	16.6	16.8	13.4	14.4	14.9
Recovered	19.4	13.2	10.8	13.8	17.1	17.0	13.1	13.0	17.8	15.2	12.3	13.3
Developed unpleasant adverse drug reactions	5.4	3.8	14.5	4.8	10.9	15.3	20.3	9.4	9.2	9.8	18.2	7.5
Had a fear of potential adverse drug reactions	16.1	9.4	8.4	4.0	17.5	8.5	16.7	7.0	17.1	8.9	14.0	5.8
Treatment was not effective	14.0	3.8	16.9	5.9	9.0	11.9	19.0	6.9	10.5	8.0	18.2	6.5
Wanted to save money	5.4	5.7	8.4	2.4	7.1	6.8	8.5	1.8	6.6	6.3	8.5	2.0

Notes: Missing values men n = 7, women n = 13.

a Several choices could be made by the same participant.

Abbreviations: Anx, anxiety; Depr, depression.

Table 4 Logistic regression analyses associating symptoms of anxiety and/or depression with various types of nonadherent behavior

	Men		Women		All
	ORa	95% CI	ORa	95% CI	ORb	95% CI
	Any nonadherence (unintentional or intentional)
Anxiety	2.44	1.45–4.09	1.37	1.00–1.88	1.61	1.23–2.10
Depression	1.43	0.84–2.43	2.37	1.30–4.34	1.81	1.22–2.69
Both	2.08	1.28–3.37	2.01	1.39–2.89	2.03	1.52–2.71
	Unintentional nonadherence (forgot to take the medication)
Anxiety	1.56	1.02–2.38	1.25	0.94–1.66	1.33	1.06–1.69
Depression	1.10	0.67–1.80	1.92	1.16–3.18	1.45	1.02–2.06
Both	2.22	1.45–3.41	1.46	1.07–1.97	1.67	1.31–2.14
	Any intentional nonadherence (see below)
Anxiety	2.02	1.32–3.09	1.49	1.12–1.98	1.62	1.27–2.05
Depression	2.32	1.40–3.86	2.96	1.74–5.03	2.60	1.80–3.74
Both	1.80	1.19–2.72	2.22	1.62–3.05	2.06	1.60–2.64
	Changed dosage of own accord
Anxiety	2.30	1.47–3.60	1.80	1.27–2.56	1.94	1.48–2.55
Depression	2.19	1.26–3.81	2.61	1.48–4.61	2.36	1.59–3.50
Both	2.02	1.30–3.15	2.55	1.80–3.61	2.32	1.76–3.04
	Discontinued a medical treatment
Anxiety	2.60	1.65–4.10	1.71	1.26–2.32	1.92	1.49–2.48
Depression	2.61	1.48–4.60	2.31	1.37–3.91	2.41	1.64–3.53
Both	1.52	0.94–2.45	1.60	1.14–2.22	1.58	1.20–2.07
	Filled a prescription but did not take the medication
Anxiety	1.48	0.92–2.38	1.30	0.95–1.76	1.33	1.03–1.73
Depression	1.58	0.88–2.84	2.22	1.33–3.69	1.92	1.32–2.82
Both	1.08	0.65–1.77	1.54	1.12–2.12	1.39	1.06–1.81
	Did not have a prescription filled
Anxiety	1.45	0.88–2.39	1.43	1.03–1.97	1.43	1.09–1.88
Depression	2.73	1.53–4.89	2.38	1.38–4.09	2.55	1.72.3.80
Both	1.87	1.17–2.99	2.22	1.59–3.08	2.10	1.60–2.74

Notes:

a Controlling for age;

b controlling for age and sex.

Abbreviations: OR, odds ratio; CI, confidence interval.

Table 5 Logistic regression analyses associating symptoms of anxiety and/or depression with various reasons for nonadherence

	Men		Women		All
	ORa	95% CI	ORa	95% CI	ORb	95% CI
	Did not need the medication
Anxiety	1.19	0.67–2.11	0.95	0.66–1.37	1.01	0.74–1.37
Depression	1.41	0.68–2.92	0.86	0.43–1.75	1.06	0.64–1.75
Both	1.05	0.59–1.86	0.72	0.47–1.10	0.81	0.57–1.14
	Recovered
Anxiety	1.10	0.63–1.90	1.24	0.85–1.82	1.18	0.87–1.61
Depression	1.46	0.74–2.87	2.32	1.27–4.26	1.87	1.19–2.93
Both	0.63	0.33–1.17	0.95	0.61–1.48	0.82	0.57–1.17
	Developed unpleasant adverse drug reactions
Anxiety	1.70	0.72–4.02	1.12	0.71–1.77	1.21	0.81–1.81
Depression	3.03	1.33–6.89	2.35	1.23–4.48	2.60	1.57–4.31
Both	2.73	1.35–5.53	2.21	1.47–3.31	2.32	1.63–3.29
	Had a fear of potential adverse drug reactions
Anxiety	3.07	1.55–6.08	2.44	1.60–3.72	2.60	1.81–3.72
Depression	2.40	0.96–6.03	1.08	0.42–2.77	1.55	0.81–2.98
Both	1.96	0.93–4.16	2.91	1.90–4.45	2.67	1.85–3.85
	Treatment was not effective
Anxiety	1.83	0.93–3.60	1.03	0.61–1.75	1.26	0.83–1.90
Depression	1.58	0.64–3.90	2.48	1.20–5.10	2.07	1.18–3.62
Both	2.33	1.25–4.35	2.72	1.77–4.18	2.60	1.83–3.70
	Wanted to save money
Anxiety	1.88	0.71–5.01	2.14	1.04–4.43	2.04	1.14–3.64
Depression	1.45	0.32–6.52	3.45	1.13–10.49	2.41	0.99–5.86
Both	3.38	1.45–7.73	4.10	2.12–7.95	3.79	2.26–6.33

Notes:

a Controlling for age;

b controlling for age and sex.

Abbreviations: OR, odds ratio; CI, confidence interval.