Beliefs that influence cost-related medication non-adherence among the “haves” and “have nots” with chronic diseases

Figures & data

Table 1 Patient characteristics

	Low income high OOP	High income low OOP	P-value
N	1,321	1,195
Age (mean, SD)	60.5, 9.6	59.5, 8.8	0.007
Female (%)	67.3	33.8	<0.001
White (%)	93.4	93.7	0.77
College degree (%)	23.4	74.7	<0.001
Employment status (%)			<0.001
Employed	21.8	59.2
Retired	35.8	26.4
Unemployed	42.3	14.4
Fair/poor health (%)	64.4	15.3	<0.001
Number of Rx (%)			<0.001
1	22.2	39.8
2	20.8	30.4
3	17.5	16.6
4+	39.5	13.2
Chronic diseases (%)
Asthma	26.4	10.5	<0.001
Hypertension	63.6	67.1	0.07
Depression	44.3	14.1	<0.001
Diabetes	36.2	18.4	<0.001
Hyperlipidemia	44.9	38.8	0.002
Osteoporosis	18.3	7.3	<0.001

Note: Percents are column percents.

Abbreviations: OOP, out-of-pocket medication costs; Rx, prescriptions.

Table 2 Cost-related non-adherence (CRN) behaviors

	Low income high OOP	High income low OOP	P-value
Any CRN (%)	79.0	14.4	<0.001
Delaying
Delayed filling a prescription (%)	72.0	6.5	<0.001
Split pills/take fewer doses (%)	64.1	11.0	<0.001
Stopping
Stopped taking Rx altogether (%)	47.9	2.5	<0.001
Did not fill a prescription at all (%)	59.3	3.5	<0.001

Note: Percents are column percents.

Abbreviations: OOP, out-of-pocket medication costs; Rx, prescriptions.

Table 3 Adjusted odds ratios predicting overall cost-related non-adherence

	Low income high OOP	High income low OOP
Medication beliefs
Need (moderate)	1.1 (0.8, 1.7)	1.9** (1.2, 3.0)
Need (low)	1.5** (1.2, 1.8)	2.1** (1.3, 3.4)
Side effects (moderate)	1.4* (1.0, 2.1)	1.3 (0.9, 1.9)
Side effects (high)	1.8** (1.2, 2.8)	2.3** (1.4, 3.7)
Diagnoses
Depression	1.8** (1.3, 2.5)	2.0** (1.3, 2.9)
Asthma	1.6** (1.1, 2.3)	2.0** (1.3, 3.2)
Pseudo R-square	0.10	0.12

Note: Models controlled for patients’ age, gender, and educational attainment.

* P < 0.05;

** P < 0.01.

Abbreviations: OOP, out-of-pocket medication costs; Rx, prescriptions.

Table 4 Adjusted odds ratios predicting cost-related nonadherence by subtype

	Slow		Stop
	Low income high OOP	High income low OOP	Low income high OOP	High income low OOP
Medication beliefs
Need (moderate)	1.3 (0.9, 1.9)	2.0** (1.3, 3.3)	1.1 (0.8, 1.6)	1.6 (0.7, 3.8)
Need (low)	1.5** (1.2, 1.9)	2.2** (1.3, 3.6)	1.4* (1.0, 2.0)	2.5* (1.1, 5.8)
Side effects (moderate)	1.4* (1.0, 2.0)	1.3 (0.9, 1.9)	1.1 (0.8, 1.5)	1.0 (0.5, 2.0)
Side effects (high)	1.7** (1.1, 2.5)	2.4** (1.5, 3.8)	1.8** (1.3, 2.6)	2.0* (1.0, 4.4)
Diagnoses
Depression	1.8** (1.3, 2.4)	1.9** (1.3, 2.9)	1.4** (1.1, 1.9)	2.2* (1.1, 4.1)
Asthma	1.5* (1.0, 2.2)	2.0** (1.3, 3.1)	1.5** (1.1, 2.0)	2.1** (1.1, 4.1)
Pseudo R-square	0.10	0.12	0.12	0.12

Notes: Slow = cost-related non-adherence involving taking less of ongoing prescriptions by (eg, taking fewer pills or delaying the time until refill); Stop = not filling a prescription at all due to cost concerns or stopping medication use completely. Models controlled for patients’ age, gender, and educational attainment.

* P < 0.05;

** P < 0.01.

Abbreviations: OOP, out-of-pocket medication costs; Rx, prescriptions.