The roles of past behavior and health beliefs in predicting medication adherence to a statin regimen

Figures & data

Table 1 Health belief matrix

Cognitive beliefs	Belief statements^a
Perceived risk of poor health	I believe there is a chance of poor health if I fail to take the medication as prescribed.
Perceived benefit	I believe the regimen has worked and met its goal.
Side effects	Side effects were present and prevented a valued activity.
Understanding of regimen	I completely understand my regimen.
Impact on daily routine	Taking my medication interrupts my daily routine.
Financial resources	I do not have adequate money to pay for my medications.
Behavioral intent	I intend to take the medication exactly as prescribed.
Social beliefs
Patient/clinician regimen dialogue	The clinician and I have mutually agreed upon the goals and the regimen for the medication.
	The clinician and I have discussed the potential side effects of the medication and how to deal with them.
	The clinician established a follow-up plan for medication regimen.
Social support (from family/friends)	I believe I will get the support I need from family and friends.

Note:

a Four-point scale ranging from 1 (strongly disagree) to 4 (strongly agree).

Table 2 Sociodemographic characteristics of the participants at baseline (n = 2789)

Subject characteristics	Eligible sample	Ineligible sample
Sample size	1433	1356
Sociodemographics
Age (years)	54.2	52.2^a
(standard deviation)	(9.79)	(9.97)
(median)	(54.9)	(53.0)
Sex (% females)	43.7	40.5^a
Race (% nonwhite)	8.7	NA
Education (years)	13.6	NA
(standard deviation)	(1.9)	NA
(median)	(13.5)	NA
Medication adherence	82.7%	78.26%^b
(standard deviation)	(18.51)	(31.75)
(median)	(88.0)	(86.1)

Notes:

a P < 0.05;

b P < 0.001.

Figure 1 Receiver operator characteristic (ROC) curves illustrating the predictive accuracy of beliefs and past behavior for medication adherence.

Table 3 Multivariate predictors of medication adherence (P < 0.05)

Belief category	Belief	Behavioral intent		Medication adherence
		OR	95% CI	OR	95% CI
Cognitive belief	Perceived risk of poor health	1.91	1.13–3.21	1.82	1.26–2.63
	Perceived benefit	1.77	1.13–2.74	NS	NS
	Side effects	1.68	1.19–5.59	NS	NS
	Impact on daily routine	3.30	1.41–7.74	NS	NS
	Not enough financial resources	1.93	1.23–3.03	1.51	1.02–2.40
Social belief	Quality of patient/doctor regimen dialogue	1.98	1.17–3.36	NS	NS
Behavioral intent	Intent to take medication	NA	NA	5.12	1.84–11.06

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