Association Between Different Types of Social Support and Medication Adherence

Objectives:

To evaluate the association between social support and medication adherence.

Study Design:

A search of articles published before November 2010 in peer-reviewed, healthcarerelated journals was conducted using PubMed, EMBASE, and Web of Science, and search terms related to social support (social support OR friend OR family OR agency) and adherence (patient compliance OR medication adherence), yielding 5331 articles.

Methods:

Articles were included if they directly measured the relationship between medication adherence and some form of social support. Excluded were case studies, studies with participants <18 years of age, and non—English language studies. Four social support categories were reported: structural, practical, emotional, and combination. Medication adherence was reported in the manner in which it was described in each study.

Results:

Fifty studies were included in the final analysis. A greater degree of practical support was most consistently associated with greater adherence to medication; evidence for structural or emotional support was less compelling. However, most studies were limited in size and design, and substantial variability in designs and outcome measurement prohibited pooling of results, necessitating qualitative evaluation of the studies.

Conclusions:

This qualitative analysis found that practical social support was most consistently associated with greater medication adherence. Interventions that use existing contacts (friends or family) to engage patients in the mundane and practical aspects of medication purchasing and administration may be an effective approach to promoting better medication adherence.

(Am J Manag Care. 2012;18(12):e461-e467)This qualitative analysis found that practical social support is consistently associated with higher medication adherence.

• Medication adherence is most closely associated with having a repertoire of close friends or providers who can consistently provide emotional and practical support that does not leave the patient with the perception of unmet needs.

• Providing people in the patient’s social network with emotional and practical skills (eg, focused on medication adherence, barriers, support, and confidence building) may have a significant impact on medication adherence.

Nonadherence to chronic medications imposes a substantial clinical and financial burden on the US healthcare system. Studies have repeatedly demonstrated that medication nonadherence is a common source of hospitalizations, morbidity, and mortality in a variety of populations and disease states.^1-3 The financial consequences of medication nonadherence in the United States are tremendous; the cost of care for patients with cardiovascular disease and diabetes are substantially greater in those who do not adhere to therapy than in those who do adhere, and total annual costs of medication nonadherence are estimated at almost $300 billion in the United States.^3,4

Despite the importance of medication nonadherence, no simple solutions are available to fix the problem.⁵ Numerous studies have aimed to improve medication adherence, yet best practices to enhance better medication taking continue to evolve.^4-6 Moreover, little is known about the most cost-effective interventions to encourage better adherence.⁷ Therefore, new, low-cost approaches to improve medication adherence are needed to promote improved health outcomes and reduce healthcare costs.

The emergence of popular online social networking websites has stimulated interest in the role of social capital or connectedness in promoting health. Greater social support has been shown to be associated with improved health outcomes and healthier behavior.⁸ Yet the role of one’s social connectedness in medication adherence has not been well defined. Considering that social support connections are wide ranging, encompassing many aspects of the relationship between the patient and the person providing the support, we know even less about how different features of one’s social support system can influence medication use.

Accordingly, we conducted a systematic review of the published literature to evaluate what is known about the association between social support and medication adherence in a variety of disease states, and to explore features of one’s social support that might encourage better behavior. To do so, we categorized social support structures into those that are more functional and those that are predominantly emotional in nature.^9,10 We aimed to evaluate the relative influence of the various types of support on medication adherence, so that appropriate and effective interventions to improve medication adherence can be designed.

METHODSStudy Selection

Figure

With the help of a professional librarian, we performed a search of articles published before November 2010 in peerreviewed, healthcare-related journals using PubMed, EMBASE, and Web of Science. We used search terms related to social support (social support OR friend OR family OR agency) and adherence (patient compliance OR medication adherence). Articles with at least 1 search term from both categories met the criteria for the initial title/abstract review. After screening for duplicate entries, the results from the 3 databases were combined and totaled 5331 articles. Of these abstracts, 169 were included for full review of inclusion and exclusion criteria ().

Articles were included if they directly measured the relationship between medication adherence and some form of social connectedness and/or support. There were 131 excluded articles, including case studies, studies with patients less than 18 years of age, non—English language publications, and studies where no medication-specific adherence measure was reported as an outcome (leaving 38 articles). Pediatric studies were excluded because the different mechanism and influence of social support in pediatric versus adult medication adherence would make conclusions difficult. The inclusion or exclusion of each article was determined by 2 reviewers independently, and disagreements were resolved by a third reviewer. All reference lists from the included articles were evaluated, and 12 additional studies (not found in our original search) were included, as determined by consensus. Data on study populations and characteristics, results, and study quality were extracted from each article using a standardized protocol and reporting form. Specific information collected included study population, social support measure, adherence measure, and adherence outcome.

Data Extraction

Table

For our key explanatory variable, social support, we defined 4 categories: structural, practical, emotional, and combination, which are further defined with examples in the . Each social support item abstracted from an included study was placed into 1 of these 4 social support categories by 2 reviewers independently, and disagreements were resolved by a third reviewer. The combination category reflects those social support items or instruments that did not distinguish the precise type of support measured, or that only reported a summary measure that included multiple support types.

Our outcome variable, medication adherence, is reported in the manner it was described in each study (Appendix). Studies that reported more than 1 social support category are represented in more than 1 table in the Appendix.

RESULTSPopulation

We included a total of 50 studies; 14 evaluated structural support, 12 practical support, 14 emotional support, and 26 combination support (Figure). Most were conducted in disease-specific populations; the most common were human immunodeficiency virus infection/acquired immunodeficiency syndrome (HIV/AIDS), diabetes, dialysis, tuberculosis, cardiovascular (hypertension and congestive heart failure), asthma, and transplant. Most were cross-sectional observational studies. Sample sizes ranged from 26 to 1198 patients.

Social Support Measurements

Almost all included studies required participants to evaluate their perception of support; 2 interviewed caregivers.^11,12 Approximately half used some variation of a previously validated instrument, and half used study-specific questionnaires. A majority utilized a self-completed survey instrument (n = 28), while fewer relied on interviews (n =16). The remainder utilized a combination of surveys and interviews, or did not describe the data collection. Most included several different types of support, while 17 measured only 1 type. Adherence was largely measured using subjective self-report, while 13 corroborated adherence objectively with pill count, refill information, or urine/serum markers of adherence.^1,2,13-23 One study used a nurse assessment of adherence.²⁴

Structural Support

We identified 14 studies that assessed the relationship between structural social support and medication adherence; this structural support was cohabitation in 4 studies,^1,20,24,25 presence of a spouse or supportive relationship in 7 studies,^22,26-31 and both in 2 studies.^14,32 In 1 study, structural social support was defined by the size of patients’ social network (Table).⁹

Of all these studies, 6 (43%) identified an association between structural support and medication adherence, but some identified a positive association and others found a negative association. Two identified relationship status as significantly associated with being more adherent, with logistic regression coefficients of 1.2 (P value not reported)26 and 2.7 (P = .02)³²; however, a third study identified having a partner as being associated with lower odds of adherence compared with not having a partner (odds ratio [OR] of adherence 0.97, P <.01),²⁸ and a fourth study found that adherence was highest in divorced persons.²⁹ Living situation (eg, living with someone) had a negative association with adherence in 2 studies (both in an HIV population).^24,32 Only 1 study found that living with a spouse or relative had a significant, but modest, association with adherence.²⁰

Of the 8 (57%) studies that did not identify an association between structural support and medication adherence, ^{1,9,14,22,25,27,30,31} most evaluated marital status or living status. Two of these studies involved large cohorts of patients with objectively measured medication adherence.^22,30 The 1 study that evaluated social network size did not identify a significant association with adherence, although it evaluated only frequency of contact, but not quality or type of the interaction.⁹

Practical Support

We identified 12 studies that assessed the relationship between practical social support and medication adherence. Practical support was assessed by subjective participant ratings about how much help they received or how satisfied they were with the help in 3 main areas: medication help (reminders to take medication, directive guidance on medications, picking up prescriptions), help with household functions (cooking, cleaning, paying bills, running errands), and help with transportation.

Of these 12 studies, 8 (67%) identified a significant association of help with adherence. Of those, all but 1 identified a significant positive association (either amount of support or satisfaction with support) with medication adherence.^11,19,33-37 The 1 study that identified a negative association was a small study with an HIV cohort, where the adherence measure was nurse-perceived adherence, a poorly validated measure of actual medication use.²⁴ Two studies analyzed the association using a multivariate technique. The first study found the number of sources of practical support was associated with adherence; having 1 source of support was not associated with higher adherence, but 2 or more sources were associated with twice the odds ofadherence compared with the adherence of patients with no sources of support (OR of adherence 2.12, 95% confidence interval [CI] 1.06-4.26; P = .004).³⁶ In the second study, participants who had an “unmet need” for benefits (eg, Medicaid, Social Security, or prescription help) had an OR of nonadherence of 2.8 (P <.01) compared with patients who did not have this unmet need; 51% of the cohort reported needing help in this area. Other unmet practical needs were not associated with adherence (housing, emergency provisions, legal assistance, or supplemental nutrition), although about two-thirds of the cohort did not report a need in those areas.³⁷

Of the 4 (33%) studies that did not identify an association, all were limited by very small sample sizes (58-112 patients), and subjective self-reports of both practical support and medication adherence.^12,38-40

Emotional Support

Observational Studies. We identified 14 observational studies that assessed the relationship between emotional support and medication adherence. Emotional support was assessed by self-report in a variety of ways, including perceived amount of or satisfaction with social support, number of social support unmet needs, or the number of friends and social support sources.

Of these studies, 6 (42%) identified a significant association between any emotional support measure and adherence. Five found a positive association between emotional support and adherence, and 1 found a mixed association between support and adherence, with a negative association between social attachment and short-term (3-day) medication adherence (OR 0.49, 95% CI 0.34-0.71; P <.01), and a positive association between higher reassurance of worth and longer term (30-day) medication adherence (OR 1.3, 95% CI 1.03-1.6; P <.05).⁴¹ Of the 5 that found a positive association, 2 found a univariate association between medication adherence and emotional support in small samples of HIV patients.^34,42 Another small study of renal transplant patients found affectionate support explained 12% of the variance in adherence in multivariable regression.³³ A large sample of HIV patients identified as having the unmet need of counseling had significantly reduced odds of being adherent (OR 0.32; P <.01), and having the unmet need of a support group significantly increased the odds of not taking medications (OR 3; P <.05).³⁷ In 1 large cohort of patients on lipid-lowering medications, the larger the number of close friends, the lower the chance of being nonadherent, with 16% nonadherence in those with no close friends and 7% nonadherence in those with 3 or more close friends (P = .04 for trend). The frequency of contact also correlated with adherence, although it did not reach statistical significance (16% nonadherence in those with less than weekly contact vs 8% nonadherence in those with at least weekly contact; P = .09).⁴³

Most of the 8 (58%) studies that did not identify an association were limited by small sample sizes (26-136 patients) with subjective self-reports of both emotional support and medication adherence.^{11,19,24,35,39,44,45} One large cohort study that did not identify a statistical association is worth mentioning. This study of 262 patients with postacute coronary syndrome found that the number of sources of support did increase the odds of adherence (compared with no sources, those with 1 source had an OR of adherence of 1.2, and those with 2+ sources of support had an OR of 1.4), although this difference did not reach statistical significance.³⁶

Interventional Studies. We identified 3 interventional studies that randomized patients to receive emotional support and evaluated the effect on medication adherence. All 3 studies focused on HIV patients (sample sizes ranging from 136 to 215). One found no effect of a peer support group (6 bimonthly group meetings and weekly phone calls) on HIV medication adherence.⁴⁵ Another study revealed that cognitive- behavioral stress management expressive-supportive therapy (10 weekly sessions) also had no overall effect on medication adherence.⁴⁶ However, the last study reported that engaging a patient and their HIV-serodiscordant partner in four 1-hour educational sessions (focused on medication adherence, barriers, support, and confidence building) significantly increased the percentage of patients who achieved at least 95% adherence with their HIV regimen (35% in the intervention group and 19% in the control group, P = .02).⁴⁷

Combination Support

We identified 26 studies that assessed the relationship between a combined support measure and medication adherence. Combined support was assessed by self-report in a variety of ways, including perceived amount of or perceived satisfaction with emotional and practical support, or the presence (or absence) of any support.

Of these studies,13 (50%) revealed a significant association between support and medication adherence. Seven studies evaluated only univariate associations with very small sample sizes (50-144 patients), making firm conclusions difficult.17,18,34,48-51 Of the remaining 6 studies, 1 revealed that adherence was lower with more support (this study was mentioned in the Emotional Support sections).⁴¹ One small cohort of renal transplant patients found that combination support explained 24% of the variance in adherence in a multivariable regression model,33 and a study with a small cohort of heart failure patients found that higher perceived support significantly predicted fewer missed medications doses (multivariable regression b -0.241, P = .14). The remaining 3 studies with HIV cohorts found that more social support was associated with greater adherence and fewer missed doses; one of the studies specifically found twice the odds of adherence in those with support versus those without support.^23,52,53

Most of the 13 (50%) studies that did not identify an association were limited by small sample sizes (30-116 patients) with subjective self-reports of support and medication adherence.^{15,16,21,27,31,39,54-58} However, 2 notable large-cohort studies are worthy of mention. The first evaluated 1141 post—myocardial infarction patients followed for 2 years; the researchers identified no significant association between social support, social networks, or social activities and adherence to antiarrhythmic medications, although they dichotomized medication adherence into “adherent” and “nonadherent” and 78% of the group was adherent, making statistical distinctions between the groups difficult.²² The other study involved a large cohort of 496 hypertensive patients who assessed (on a 4-point scale) whether friends or family attempted to help them take their hypertension medications properly. The study did not report the mean amount of support, so it is not clear whether the study population’s support level was diverse enough to detect an association between support and adherence.¹³

DISCUSSION AND CONCLUSIONS

Medication nonadherence is a burden to the United States healthcare system, resulting in higher healthcare costs and poorer patient outcomes. This analysis assessed the direction and strength of the association between social support and medication adherence, and categorized social relationships into structural, practical, emotional, and combined support. We found, qualitatively, that greater practical support of medication taking was most consistently associated with greater adherence to therapy.

Structural support, as defined by cohabitation or support from a spouse/significant other, was not consistently associated with medication adherence. This implies that the mere presence of a spouse/partner is not sufficient to affect behavior. Similarly, fewer than half of the studies we found demonstrated a relationship between emotional support and adherence. Emotional support was found to correlate best with adherence when it involved meeting unmet needs or having close friends. The interventional studies did not find that emotional support by peer or specialty providers had a significant effect on medication adherence. However, 1 interventional study did find engaging and empowering an emotionally invested partner did improve mediation adherence, at least in HIV care.

On the other hand, practical support—as defined by the number of sources (or satisfaction with the sources) of practical support for medication reminders, household responsibilities, or transportation&mdash;was consistently associated with improved medication adherence. Improved medication-taking behavior was most closely associated with assistance in the very process of purchasing or administration of therapy. The one study that evaluated practical support using multivariate techniques found a dose-response relationship; an increased number of sources of practical support was associated with increased adherence.³⁶ This result may imply that redundancy in the support network may be vital to ensure overall consistency in receipt of support. Findings from the analysis of combination support were mixed, but were limited by small sample sizes, primarily univariate analysis techniques, and heterogeneity in the definition of support.

Despite the low cost and intuitive appeal of interventions utilizing social contacts to promote better adherence, little prospective evidence exists to understand the effectiveness of this approach. The observational design of the majority of the studies in our review limits our ability to assess causation. It is possible that patients who receive meaningful support from family or friends when purchasing or administering medication differ in other important ways from those who do not. Moreover, most of the studies assessing emotional or combination support were limited in size and design, leading to difficulty in drawing firm conclusions about the nature and magnitude of the relationships identified. There was variability in the methods of collecting both the explanatory and outcome variables in the studies we analyzed. Due to this variability, we were unable to pool results across studies and conducted a qualitative review of the literature. While specific types of social support were associated with varying levels of adherence, the strength of the effect of each type has not been clearly quantified.^9,10 As a result, this review does not provide a quantitative assessment of a specific hypothesis, but rather synthesizes a complex literature and assesses the evidence to date regarding the relationship between social connectedness and medication adherence.

Despite these limitations, our review does suggest that practical aspects of medication taking may be the most fertile locus for interventions in future studies. Using existing contacts (friends or family) to engage patients in the mundane and practical aspects of medication purchasing and administration may be an effective approach to promoting better medication adherence. Such an approach could be low cost and could leverage existing relationships to encourage better chronic disease management. Future studies should evaluate the feasibility and efficacy of assigning family or friends to provide this level of support to patients. Additionally, studies are needed to assess the efficacy of increasing the “bandwidth” or redundancy of a support network, or arming other members of the social network with the emotional and practical skills needed to enhance medication adherence. As more Americans use online social networks to garner emotional support and to answer specific questions about the management of chronic disease, explicit study of how to promote medication adherence by engaging willing patients in these networks also is needed.Author Affiliations: From Department of Medicine (DS), Medical University of South Carolina, Charleston, SC; Division of Pharmacoepidemiology and Pharmacoeconomics (NC, WS), Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA; Center for American Political Studies (KAS), Harvard University, Boston, MA; CVS Caremark (OM), Boston, MA.

Funding Source: Unrestricted research grant from CVS Caremark.

Author Disclosures: Dr Choudhry reports receiving unrestricted grants from CVS Caremark, Aetna, Commonwealth Fund and the Robert Wood Johnson Foundation to study medication adherence. Dr Shrank reports receiving grants from CVS Caremark, the National Association of Chain Drug Stores, Eli Lilly and Company, and Teva. The other authors (DS, OM) report no relationship or financial interest with any entity that would pose a conflict of interest with the subject matter of this article.

Authorship Information: Concept and design (DS, NC, KAS, WS); acquisition of data (KAS, WS); analysis and interpretation of data (DS, NC, KAS, OM, WS); drafting of the manuscript (DS); critical revision of the manuscript for important intellectual content (DS, NC, OM, WS); provision of study materials or patients (WS); obtaining funding (WS); administrative, technical, or logistic support (KAS, OM, WS); and supervision (WS).

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