In or out? Methodological considerations for including and excluding findings from a meta-analysis of predictors of antiretroviral adherence in HIV-positive women

What Synthesis Methodology Should I Use? A Review and Analysis of Approaches to Research Synthesis

BACKGROUND

When we began this process, we were doctoral students and a faculty member in a research methods course. As students, we were facing a review of the literature for our dissertations. We encountered several different ways of conducting a review but were unable to locate any resources that synthesized all of the various synthesis methodologies. Our purpose is to present a comprehensive overview and assessment of the main approaches to research synthesis. We use 'research synthesis' as a broad overarching term to describe various approaches to combining, integrating, and synthesizing research findings.

METHODS

We conducted an integrative review of the literature to explore the historical, contextual, and evolving nature of research synthesis. We searched five databases, reviewed websites of key organizations, hand-searched several journals, and examined relevant texts from the reference lists of the documents we had already obtained.

RESULTS

We identified four broad categories of research synthesis methodology including conventional, quantitative, qualitative, and emerging syntheses. Each of the broad categories was compared to the others on the following: key characteristics, purpose, method, product, context, underlying assumptions, unit of analysis, strengths and limitations, and when to use each approach.

CONCLUSIONS

The current state of research synthesis reflects significant advancements in emerging synthesis studies that integrate diverse data types and sources. New approaches to research synthesis provide a much broader range of review alternatives available to health and social science students and researchers.

Predictors of medication adherence among HIV-positive women in North America

OBJECTIVE

To explore the relationships among contextual, environmental, and regulatory factors with antiretroviral (ARV) medication adherence to assist care providers in improving care for women living with HIV.

DESIGN

Descriptive, multicenter study.

SETTING

Sixteen HIV clinics and service organizations in North America.

PARTICIPANTS

This convenience sample was drawn from a larger study of 2,182 persons living with HIV recruited from clinics and service from September 2009 to January 2011. We included 383 women living with HIV who were taking ARV medications.

METHODS

We assessed the relationship of contextual, environmental, and psychological factors specific to women living with HIV in relation to adherence to ARV medication. Descriptive and multivariate statistics were used to examine the effects of these factors on self-reported ARV drug adherence.

RESULTS

Age, depression symptoms, stigma, engagement with health care provider, and four psychological factors were correlated with self-reported ARV medication adherence (p = .01). Regression analysis indicated that adherence self-efficacy and depression symptoms accounted for 19% for 3-day and 22% for 30-day self-reported medication adherence.

CONCLUSIONS

Adherence self-efficacy and depression symptoms predict ARV medication adherence in women and should be evaluated by nurses. Future research is needed to identify antecedents to and interventions that support adherence self-efficacy and decrease depression symptoms.

Mapping the Mixed Methods-Mixed Research Synthesis Terrain

Mixed methods-mixed research synthesis is a form of systematic review in which the findings of qualitative and quantitative studies are integrated via qualitative and/or quantitative methods. Although methodological advances have been made, efforts to differentiate research synthesis methods have been too focused on methods and not focused enough on the defining logics of research synthesis-each of which may be operationalized in different ways-or on the research findings themselves that are targeted for synthesis. The conduct of mixed methods-mixed research synthesis studies may more usefully be understood in terms of the logics of aggregation and configuration. Neither logic is preferable to the other nor tied exclusively to any one method or to any one side of the qualitative/quantitative binary.

A mixed-methods approach to synthesizing evidence on mediators of intervention effects

Greater understanding of the mechanisms (mediators) by which behavioral-change interventions work is critical to developing theory and refining interventions. Although systematic reviews have been advocated as a method for exploring mediators, this is rarely done. One challenge is that intervention researchers typically test only two paths of the mediational model: the effect of the intervention on mediators and on outcomes. The authors addressed this challenge by drawing information not only from intervention studies but also from observational studies that provide data on associations between potential mediators and outcomes. They also reviewed qualitative studies of participants' perceptions of why and how interventions worked. Using data from intervention (n = 37) and quantitative observational studies (n = 55), the authors conducted a meta-analysis of the mediation effects of eight variables. Qualitative findings (n = 6) contributed to more in-depth explanations for findings. The methods used have potential to contribute to understanding of core mechanisms of behavioral-change interventions.

A systematic review comparing antiretroviral adherence descriptive and intervention studies conducted in the USA

We examined the extent to which studies aimed at testing interventions to improve antiretroviral adherence have targeted the facilitators of and barriers known to affect adherence. Of the 88 reports reviewed, 41 were reports of descriptive studies conducted with US HIV-positive women and 47 were reports of intervention studies conducted with US HIV-positive persons. We extracted from the descriptive studies all findings addressing any factor linked to antiretroviral adherence and from the intervention studies, information on the nature of the intervention, the adherence problem targeted, the persons targeted for the intervention, and the intervention outcomes desired. We discerned congruence between the prominence of substance abuse as a factor identified in the descriptive studies as a barrier to adherence and its prominence as the problem most addressed in those reports of intervention studies that specified the problems targeted for intervention. We also discerned congruence between the prominence of family and provider support as factors identified in the descriptive studies as facilitators of adherence and the presence of social support as an intervention component and outcome variable. Less discernible in the reports of intervention studies was specific attention to other factors prominent in the descriptive studies, which may be due to the complex nature of the problem, individualistic and rationalist slant of interventions, or simply the ways interventions were presented. Our review raises issues about niche standardization and intervention tailoring, targeting, and fidelity.

Making Sense of Qualitative and Quantitative Findings in Mixed Research Synthesis Studies

The synthesis of qualitative and quantitative research findings is increasingly promoted, but many of the conceptual and methodological issues it raises have yet to be fully understood and resolved. In this article, we describe how we handled issues encountered in efforts to synthesize the findings in forty-two reports of studies of antiretroviral adherence in HIV-positive women in the course of an ongoing study to develop methods to synthesize qualitative and quantitative research findings in common domains of health-related research. Working with these reports underscored the importance of looking past method claims and ideals and directly at the findings themselves, differentiating between aggregative syntheses in which findings are assimilated and interpretive syntheses in which they are configured, and understanding the judgments involved in designating relationships between findings as confirmatory, divergent, or complementary.