Self-Efficacy Mediates the Relationship Between Depressive Symptoms and Medication Adherence Among Hypertensive African Americans

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2009 36: 127 originally published online 12 December 2007Health Educ BehavAntoinette Schoenthaler, Gbenga Ogedegbe and John P. Allegrante

Medication Adherence Among Hypertensive African AmericansSelf-Efficacy Mediates the Relationship Between Depressive Symptoms and

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Self-Efficacy Mediates the RelationshipBetween Depressive Symptoms and

Medication Adherence AmongHypertensive African Americans

Antoinette Schoenthaler, EdDGbenga Ogedegbe, MD, MS, MPH

John P. Allegrante, PhD

Many studies have documented the negative effects of depression on adherence to recommended treat-ment; however, little is known about the mechanism underlying this relationship. Using the Kenny and Baronanalytic framework of mediation, the authors assessed whether self-efficacy mediated the relationshipbetween depression and medication adherence in 167 hypertensive African Americans followed in a primarycare practice. Depressive symptoms are associated with poor medication adherence (β = .013, p = .036) andlow self-efficacy (β = –.008, p = .023). Self-efficacy is negatively associated with medication adherence atfollow-up (β = –.612, p < .001). The relationship between depressive symptoms and medication adherencebecomes nonsignificant when controlling for self-efficacy (β = .010, p = .087). Implications for further exam-ination into the mediating role of self-efficacy and the deleterious effect of depression on medication adher-ence are discussed.

Keywords: African American; depressive symptoms; hypertension; medication adherence; self-efficacy

The disproportionately higher prevalence of cardiovascular disease and mortality inAfrican Americans compared to Caucasians is well documented (Chobanian et al., 2003;Wong, Shapiro, Boscardin, & Ettner, 2002). Hypertension affects 39% of AfricanAmericans, compared to 29% of Whites (Ong, Cheung, Man, Lau, & Lam, 2007) andremains one of the major reasons for the racial mortality gap between African Americans

127

Antoinette Schoenthaler, Teachers College, Columbia University, NewYork. Gbenga Ogedegbe, Collegeof Physicians and Surgeons, Columbia University, NewYork. John P. Allegrante, Teachers College, ColumbiaUniversity, NewYork.

Address correspondence to Antoinette Schoenthaler, Department of Health and Behavior Studies,Teachers College, Columbia University, 525 West 120th St., NewYork, NY 10027; phone: (212) 678-3964;e-mail: [email protected].

This research is supported by NRSA Fellowship F31 081926-01 from the National Heart, Lung, andBlood Institute and in part by R01 HL 069408 and R24 HL 76857 from the National Heart, Lung, andBlood Institute, National Institutes of Health, Bethesda, Maryland. We gratefully acknowledge JacquelineSpencer for permitting us to collect data at her primary care clinic and William Chaplin his for assistancewith data analysis.

Health Education & Behavior, Vol. 36 (1): 127-137 (February 2009)DOI: 10.1177/1090198107309459© 2009 by SOPHE



and Caucasians (Wong et al., 2002). Numerous studies have sought to understand the rea-sons for the disproportionate rates of hypertension-related complications in AfricanAmericans compared to Whites (Hertz, Unger, Cornell, & Saunders, 2005; Sowers,Ferdinand, Bakris, & Douglas, 2002). Poor adherence to prescribed antihypertensive med-ications has been indicated as a major contributor to inadequate blood pressure (BP) con-trol and may explain the racial disparity in health outcomes between African AmericansandWhites (Bosworth et al., 2006).As such, understanding the reasons for poor adherencein African Americans may provide insights into developing intervention approaches toreduce the racial gap in hypertension-related complications between African Americansand Caucasians.

Psychosocial factors have been identified as important determinants of medicationadherence among hypertensive patients (Kim, Han, Hill, Rose, & Roary, 2003;Wang et al.,2002). One important psychosocial factor that has been investigated is depressive symp-toms (Kim et al., 2003; Neutel & Smith, 2003; Wang et al., 2002; Wang et al., 2005). Ina meta-analysis, Wing, Phelan, and Tate (2002) found that depressed individuals withchronic diseases were three times more likely than those who were not depressed to benonadherent to their treatment regimens.Among patients with diabetes, the long-term neg-ative effect of depressive symptoms on medication adherence leads to a higher burden ofdisease-specific symptoms, functional impairment, and difficulties in self-management(Ciechanowski, Katon, & Russo, 2000). However, despite research documenting the asso-ciation between depressive symptoms and medication adherence in patients with hyper-tension (Kim et al., 2003; Wang et al., 2002), the mechanism underlying this relationshipis not well understood. One potential mechanism that has gained increasing attention in thehealth behavior research literature is self-efficacy.

According to Bandura (1977), self-efficacy refers to an individual’s perception ofhow capable he or she will be to carry out a specific task to produce a desired outcome.Self-efficacy is a well-known predictor of health-related behavior (Brus, van de Laar,Taal, Rasker, & Wiegman, 1999; Katz et al., 1998). Individuals with chronic diseaseswho perceive high levels of self-efficacy are more likely to cognitively appraise theircapabilities positively and thus more likely to perform health-related behaviors in futuresituations (Kobau & DiIorio, 2003). Several studies have shown that self-efficacyderives from the cognitive appraisal one gives to one’s performance, with depressivesymptoms predicting lower levels of efficacy (O’Leary, 1985). It is thus plausible thatpatients with significant depressive symptomatology may be less likely than their non-depressed counterparts to adhere to their treatment regimens because they possesslower self-efficacy. The rationale is if an individual possesses a depressive cognitiveschema, he or she is more likely than nondepressed individuals to inaccurately appraisehis or her capabilities and develop low self-efficacy. When challenged with obstacles orfailures, depressed individuals experience self-doubt in the form of lower self-efficacyand decrease their efforts, subsequently leading to an inability to carry out recom-mended health-related behaviors such as adherence to medication (Clark & Dodge,1999). To date, no study has examined the role that self-efficacy plays in mediating therelationship between depressive symptoms and medication adherence in patients withhypertension.

In this study, we assessed whether self-efficacy mediated the relationship betweendepressive symptoms and medication adherence among 167 hypertensive AfricanAmericans followed in a primary care practice. We hypothesized that self-efficacy medi-ates the negative relationship between depressive symptoms and self-report medicationadherence.

128 Health Education & Behavior (February 2009)



METHOD

Participants

The present study was embedded within a larger clinical trial that was designed toevaluate the effect of a behavioral intervention on medication adherence in hypertensiveAfrican Americans followed in a community health center in NewYork City. Details ofthe methods are provided elsewhere (Ogedegbe et al., 2007). Eligible patients were iden-tified via electronic medical records if they (a) self-identified as African American orBlack, (b) had a diagnosis of hypertension with International Classification of Disease,Ninth Revision codes 401 to 401.9, (c) were taking at least one antihypertensive med-ication, (d) were 18 years of age or older, and (e) spoke fluent English. Participants wereexcluded if they (a) had a diagnosis of cognitive impairment or serious medical condi-tion as determined by their primary care physician, (b) were unable to give informedconsent, or (c) refused to participate. Patients were recruited from two primary care prac-tices affiliated with NewYork Presbyterian Hospital’sAmbulatory Care Network (ACN);one was a community-based practice, whereas the other was a hospital-based practice.The ACN is a consortium of more than 20 community health centers that serve low-income, predominantly minority populations in underserved areas of New York City.Physicians of eligible patients were notified of their patients’ potential eligibility andasked permission to enroll their patients into the study. On enrollment, all participantswere provided written informed consent approved by the institutional review boardsof Columbia University Medical Center and the Weill–Cornell New York PresbyterianMedical Center.

Baseline assessments for the parent trial were performed no later than 1 week afterenrollment into the study. During the baseline evaluation, data were collected on patientdemographic characteristics, clinical history (duration of diagnosis of hypertension,treatment for hypertension, number of prescribed antihypertensive medications and theirdoses), and measures of self-report medication adherence, self-efficacy, and depressivesymptomatology. In addition, medical records were reviewed for baseline clinic BP read-ings and medical comorbidity. Following completion of the baseline assessment, patientswere randomly assigned to either the usual care or motivational interviewing group, andan appointment was scheduled for them to return to the clinic for their first 3-month visit.For those randomized to the intervention arm, the initial motivational interviewing ses-sion was conducted after the patient was administered the 3-month follow-up measures,thus eliminating any influence the behavioral intervention may have had on the presentstudy’s outcome measures. Trained research assistants administered self-report measuresto assess depressive symptoms at baseline and medication adherence and self-efficacy at3 months. The analysis for this study is limited to patients who completed the baselineand 3-month assessments.

Measures

Demographic Data. Patient gender, age, marital status, employment status, educa-tional status, and income level were collected at baseline from participants.

Comorbidity. History of comorbidity was recorded at baseline using the CharlsonComorbidity Index, which is a weighted index designed to evaluate the longitudinal risk ofmortality attributable to comorbid disease (Charlson, Pompei, Ales, & MacKenzie, 1987).

Schoenthaler et al. / Self-Efficacy and Depressive Symptoms in Adherence 129



Depressive Symptoms. Depressive symptoms were assessed at baseline with the well-validated 20-item Center for Epidemiological Studies Depression Scale (CES-D). Thescale is scored as a continuous measure, ranging from 0 to 60, with a cutoff score of 16or greater indicative of depressive symptoms (Farmer et al., 1988).

Self-Efficacy. Self-efficacy was assessed at the 3-month follow-up with the MedicationAdherence Self-Efficacy Scale (MASES), a 26-item, patient-derived, self-report ques-tionnaire developed to measure situation-specific efficacy beliefs regarding adherence toprescribed antihypertensive medications in African Americans (Ogedegbe, Mancuso,Allegrante, & Charlson, 2003). Cronbach’s alpha coefficient (.95) and test–retest reliabil-ity of the measure’s items (.84) demonstrate that the MASES is internally consistent andyields stable scores over time. Using a 4-point Likert-type response format ranging fromnot at all sure to extremely sure, participants rated their degree of confidence in takingtheir BP medications under a variety of situations that may pose difficulties to them.A sample of situations from the scale includes “When there is no one to remind you,”“The medication causes side effects,” and “You are afraid of becoming dependent onthem.”A summary score is computed by summing the responses, with higher scores indi-cating higher self-efficacy.

Medication Adherence. Self-reported adherence was assessed at the 3-month follow-up with the well-validated 4-item scale developed by Morisky, Green, and Levine (1986)that specifically addresses medication-taking behavior during the past week. Participantsare asked to respond yes or no to the following questions: (a) “Have you ever forgotten totake your blood pressure medicine?” (b) “Are you sometimes careless in regards to yourmedicine?” (c) “Do you skip your medicine when you are feeling well?” and (d) “Whenyou feel badly due to the medicine, do you skip it?” Each positive answer is assigned ascore of 1, with a total possible score of 4. Self-reported adherence was reported as a con-tinuous measure, with higher scores indicating poorer medication adherence.

The Morisky scale was chosen because it has been shown to be a reliable measure ofmedication adherence in studies with hypertensive patients. For instance, in a study of 88hypertensive patients, it was found to have a sensitivity of 72%, with a specificity of 74%for adherence to at least 80% of prescribed medications (Morisky et al., 1986). The mea-sure has also been utilized in studies composed of inner-city hypertensive patients andfound to have an alpha of .90 (Shea, Misra, Ehrlich, Field, & Francis, 1992).Although theelectronic Medication Events Monitoring System was utilized in the larger trial, an insuf-ficient number of patients (n = 79) had adequate data at the 3-month follow-up to be ana-lyzed for the purposes of this study.

Analytic Framework and Data Analysis

Data analyses focused on depressive symptoms at baseline, whereas medication adher-ence and self-efficacy measures were examined at 3-month follow-up. The mediationalanalytic framework described by Baron and Kenny (1986; see Figure 1) guided the ana-lytic plan.According to this approach, a mediating role of a variable exists when four con-ditions are met: (a) the baseline predictor variable must be significantly related to theoutcome variable, (b) the hypothesized mediator must be significantly related to the pre-dictor variable, (c) the mediator must be significantly related to the outcome, and finally(d) the relationship between the predictor and the outcome variables must be significantlyreduced when controlling for the mediator.




Four regression models were used to estimate the relative effect size (β coefficient)needed to satisfy the four criteria for a mediational effect. Medication adherence at the3-month follow-up was the outcome variable, baseline depressive symptoms was thepredictor variable, and 3-month self-efficacy was the hypothesized mediator (Baron &Kenny, 1986). In Pathway 1, we tested the effect of baseline depressive symptoms on 3-month medication adherence. In Pathway 2, we tested the effect of baseline depressivesymptoms on 3-month self-efficacy. In Pathway 3, we tested the effect of 3-month self-efficacy on 3-month medication adherence. Finally, we tested the combined effect ofbaseline depressive symptoms and 3-month self-efficacy on 3-month medication adher-ence (Pathway 4, shown in Figure 2). Statistical significance was set at p ≤ .05 for allregression models. Variables that may potentially have an effect on medication adher-ence, such as age, gender, level of education, income level, and presence of medicalcomorbidity, were included in the mediational model if they were significant at p < .05.

Mediation was determined with statistical significance and changes in the magnitudeof correlation coefficients (β coefficient) between the Pathways 1 and 4. A mediationaleffect is demonstrated if the addition of 3-month self-efficacy obviates the statisticallysignificant relationship between baseline depressive symptoms and 3-month medicationadherence. The Arioan version of the Sobel test was used to determine if the mediatingeffect of self-efficacy was statistically significant (i.e., whether the absolute size of theunstandardized regression coefficient from depressive symptoms to medication adher-ence would be significantly reduced; Aroian, 1947; Baron & Kenny, 1986; Sobel,1982). This version of the Sobel test provides a more conservative test of the mediationeffect (by including standard error in the equation) than do other tests (McKinnon,Warsi, & Dwyer, 1995a, 1995b).

RESULTS

Patient Characteristics

For the parent trial, 529 patients were screened. Of the 330 who met eligibility crite-ria, 190 were enrolled. Reasons for ineligibility included inadequate BP data (n = 43),BP being under control (n = 59), currently not being prescribed antihypertensive med-ications (n = 25), being deemed too ill to participate by the primary physician (n = 53),or refusal to participate (n = 19). These patients had greater Charlson comorbidity scoresthan did those included in the analysis, but there was no significant difference between


Figure 1. Baron and Kenny mediational model of the conceptual relationship among depres-sive symptoms, self-efficacy, and medication adherence

MEDIATORSelf-Efficacy

2 3

1PREDICTOR

BaselineDepressiveSymptoms

OUTCOME3-Month

MedicationAdherence



both groups in proportion of nonadherent patients (p = .14). Of the 330 eligible patientsnot enrolled in the parent trial, reasons for exclusion from the main trial included nothaving a medical appointment at the participating sites during the previous year (n = 74),patient not self-identifying as African American or Black (n = 16), too ill to participate(n = 18), and refusal to participate (n = 31). There was no significant difference betweenpatients who enrolled and those who did not. Thus, a total sample of 190 patients wasenrolled into the trial, with 81% from the community-based practice and 19% from thehospital-based practice. Of these, 8 patients withdrew from the study prior to the3-month follow-up, 10 patients did not complete the 3-month Morisky measure of adher-ence, 2 patients were lost to follow-up, 2 patients refused to answer the CES-D, and1 patient died 1 month prior to the baseline assessment. In all, data were obtained andanalyzed for a final sample of 167 participants for the present study.

Of participants, 85% were female, with a mean age of 54 years. A majority of par-ticipants (74%) had Medicaid, 45% had at least a high school diploma, 54% wereunemployed, and 64% reported a household income of less than $20,000. Mean systolicBP was 144 mmHg (SD ± 19.08), with a mean diastolic BP of 87 mmHg (SD ± 11.39).Approximately 33% had diabetes, 8% had heart failure, and 4% had kidney disease.Almost half of the patients (40%) had a Charlson comorbidity index score greater than3, with 24% reporting some form of target organ damage, including heart failure, kid-ney disease, or stroke. The median duration of diagnosis was 10 years, the mean lengthof treatment at the community clinic was approximately 3.5 years, and, on average,


Figure 2. Mediational model showing both the direct and the mediated pathways by whichdepressive symptoms influences adherence.

NOTE: In Pathway 4, 3-month self-efficacy mediates the relationship between baseline depres-sive symptoms and 3-month medication adherence (R2 = .147). Standard error is reported inparentheses. Adherence scores range from 0 to 4, with higher scores indicating better medicationadherence.*p < .05.

Pathway 1

3-MonthAdherence

OUTCOME

0.013*


ns

Pathway 2 Pathway3

(0.006)


-0.008* -0.612* (0.003) (0.142)

0.010

(0.006)

3-MonthSelf-EfficacyMEDIATOR

3-MonthAdherence

OUTCOME

Pathway 4



patients were prescribed 1.61 antihypertensive medications, with diuretics and ACEinhibitors being the most frequently prescribed (52% and 43%, respectively).

The mean CES-D score was 12.9 (SD ± 11.37), and 33% of the sample met the CES-D criteria for depressive symptoms (score > 16). The mean score on the MASES was3.46 (SD ± 0.48). The mean medication adherence score was 0.68 (SD ± 0.876, range =0 to 4), and 47% of patients were nonadherent at 3 months (i.e., responded yes to at leastone item). An ANOVA revealed that there were no significant relationships betweenmedication adherence and age, gender, level of education, comorbidity, income, insur-ance status, or baseline BP reading.

Mediation Model Pathways

Pathway 1—Effect of Depressive Symptoms on Medication Adherence. For this path-way, baseline depressive symptoms were significantly correlated with poor medicationadherence at 3 months (β = .013, p = .036). Controlling for patients’ demographic char-acteristics (age, gender, educational status, income level, and medical comorbidity)revealed that lower educational attainment was a significant independent predictor ofpoorer adherence (β = –.22, p = .013).

Pathway 2—Effect of Depressive Symptoms on Self-Efficacy. For this pathway,baseline depressive symptoms were negatively correlated with 3-month self-efficacy(β = –.008, p = .023). Controlling for patient demographics did not reveal any signif-icant associations with self-efficacy.

Pathway 3—Effect of Self-Efficacy on Medication Adherence. For this pathway,self-efficacy was negatively correlated with poorer medication adherence at 3 months(β = –.612, p < .001). The negative relationship between the variables results frommedication adherence being scored as a continuous variable, with lower scores indi-cating better adherence. As with Pathway 1, lower educational attainment predictedpoorer adherence (β = –.226, p = .010).

Pathway 4—Combined Effects. For this pathway, we sought to determine whetherself-efficacy mediated the relationship between depressive symptoms and medicationadherence. As shown by Pathway 4, when self-efficacy was added to Pathway 1, therelationship between baseline depressive symptoms and 3-month medication adherencewas no longer statistically significant (β = .010, p = .087). The calculated Aroian testconfirmed that the mediation was significant (Z = 2.43, p = .015). Thus, self-efficacyassessed at the 3-month follow-up fully mediated the relationship between baselinedepressive symptoms and medication adherence at 3 months.

DISCUSSION

In this study, we tested whether self-efficacy mediated the relationship betweendepressive symptoms and medication adherence in hypertensive African Americanpatients. We found that self-efficacy mediated the relationship between baseline depres-sive symptoms and medication adherence. Our findings may be explained by the negativerelationship between self-efficacy and depressive symptoms using Beck’s (1967) modelof depression. An individual’s negative view of self, and negative interpretation of current




experiences and future events, can explain how cognitive attributions affect self-efficacyand motivation.When challenged with obstacles, depressed individuals experience doubtsor negatively appraise their capabilities and thus tend to decrease their efforts or give up,with a resultant low self-efficacy (Clark & Dodge, 1999).

Our findings reflect those of other studies that have demonstrated the mediating roleof self-efficacy on self-management and health-related behaviors in patients withchronic diseases, including diabetes (Sacco et al., 2005), chronic pain (Arnstein, 2000),and arthritis (Allegrante & Marks, 2003). For example, using the MultidimensionalDiabetes Questionnaire, Self-Efficacy subscale, Sacco et al. (2005) found that among 56type 2 diabetic outpatients, self-efficacy mediated the relationship between depressivesymptoms and nonadherence to a self-care regimen. In a sample of chronic pain patientswith and without a history of depressive symptoms, self-efficacy mediated the relation-ship between pain intensity and self-reported pain disability (Arnstein, 2000). Similarly,among patients with osteoarthritis, self-efficacy beliefs were found to mediate key arthri-tis-related outcomes such as suffering, feelings of helplessness, and overt pain behaviors(Allegrante & Marks, 2003).

Although our findings are consistent with those of the aforementioned studies(Allegrante & Marks, 2003; Arnstein, 2000; Sacco et al., 2005), these studies were cross-sectional in nature and did not elucidate the directionality of the relationship between thepredictor and outcome variables or the predictive role of self-efficacy.As such, one strengthof our study is its longitudinal nature, which demonstrates that depressive symptoms neg-atively influence medication adherence during a 3-month period and, furthermore, that thisrelationship was mediated by self-efficacy over this time. A post hoc analysis of a smok-ing cessation behavioral intervention supports this finding (Cinciripini et al., 2003). In thisstudy, the authors found that self-efficacy assessed between 2 and 4 weeks postcessationsignificantly mediated the relationship between precessation depressed mood and 6-monthabstinence from smoking.

Despite the importance of the present study’s results, the findings must be interpretedwith caution. Although statistically significant, the unstandardized regression coefficientsrelating depressive symptoms to medication adherence and perceived self-efficacy weresmall.As demonstrated by previous studies, medication adherence is influenced by a myr-iad of factors, of which depressive symptoms is one possible determinant (World HealthOrganization [WHO], 2003). This point is evidenced in the present study, whereby lowereducational attainment was a significant independent predictor of worse medicationadherence. In all, these findings suggest that it may be more beneficial to target behaviorsand personal factors that may more directly affect medication adherence and disease out-comes than to target depression alone (Rose, Kim, Dennison, & Hill, 2000).

We should note the following limitations of our study. First, although the CES-D is areliable measure of depressive symptoms, scoring above the cutoff score does not guar-antee clinical diagnosis of depression. Furthermore, the questionnaire we used askedparticipants only to rate the frequency of specific feelings in the past week. Many con-textual issues could have influenced patient responses, possibly skewing the actualdiagnosis of depression that may have been different had a more in-depth, structuredinterview been utilized. Second, medication adherence was assessed by self-report,which may have led to an overestimation of adherence levels. However, results ofour study showed that 47% of the patient population reported being nonadherent at3 months, which is similar to the estimated 50% to 70% range of nonadherence ratesdocumented by the WHO (2003) adherence report. Patients’ adherence status was also




compared to their baseline BP readings to provide a more objective assessment of theeffectiveness of the medication adherence measure. Although not significant, patientscategorized as adherent had lower SBP and DBP readings at baseline compared topatients identified as nonadherent (SBP: 142 mmHg vs. 144 mmHg, p = .07, respec-tively; DBP: 86 mmHg vs. 87 mmHg, p = .19, respectively). Note that to be eligible forthe parent trial, patients had to possess uncontrolled BP at the baseline visit, which wasthe same visit when the present study’s BP measurements were collected.

Finally, although our analyses revealed that CES-D scores did not significantly differamong the male and female participants (results not shown), the vast majority of oursample was female, and although this is typical of many studies in African Americans,generalizability of our results is limited nonetheless. Specifically, when compared totheir male counterparts, women are more likely to exhibit comorbid depressive symp-toms, report somatic symptoms, and seek mental health assistance from their primarycare provider, and they have a higher rate of health care utilization (Bertakis et al., 2001).As a result, women are significantly more likely to be diagnosed with depression by theirprovider compared to males (Bertakis et al., 2001). Although the reasons for the highprevalence of depression among women are not clearly understood, it has been arguedthat a proportion of the disparity is because of providers’ tendency to overdiagnosewomen based on gender-role expectations. Thus, it is plausible that the associationbetween depressive symptoms and medication adherence in this study may be an artifactof gender bias rather than a true relationship, which is, in part, supported by the lowregression coefficients found in the mediational model.

In conclusion, using the Baron and Kenny analytic framework of mediation, weassessed whether self-efficacy mediated the relationship between baseline depressivesymptoms and 3-month self-reported medication adherence in 167 hypertensive AfricanAmericans followed in a primary care practice. Our findings indicate that depressivesymptoms were significantly related to medication adherence and that self-efficacy medi-ated this relationship in this group of hypertensive African American patients.

Implications for Practice

Our results suggest that self-efficacy plays an important role in explaining the nega-tive impact of depressive symptoms on medication adherence in this patient population.Two major implications for clinical practice can be drawn from these findings. First, theyunderscore the importance of assessing the influence depressive symptomatology has onmedication adherence among patients with uncontrolled hypertension and other chronicdiseases. Second, and perhaps more important, further assessment of situations in whichdepressed patients experience low self-efficacy and thus difficulty in adhering to theirmedications will provide a key starting point for patient education in the clinicalencounter. Patient participation in activation interventions, for example, has the potentialto produce significant benefits for depressed individuals. Intervention approaches thatspecifically target self-efficacy could also increase the confidence of patients in theirability to actively participate in their health care, resulting in better medication adher-ence. Finally, with regard to clinical practice, medical education should increase institu-tional efforts to better train primary care physicians in surveillance for depression and inidentifying and understanding the consequences of comorbid depression among individ-uals with chronic diseases.




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Self-Efficacy Mediates the Relationship Between Depressive Symptoms and Medication Adherence Among Hypertensive African Americans