Fitzpatrick-Lewis et al. BMC Public Health 2011, 11:638 http://www.biomedcentral.com/1471-2458/11/638 Critical Appraisal The Effective Public Health Practice Project (EPHPP) has developed and tested a tool for assessing the metho- dological quality of primary studies in public health [8]. The tool is based on previously established guidelines [9,10], has been examined by experts in the field, and has received excellent ratings [11]. This tool and accom- panying dictionary are available at http://www.ephpp.ca. This tool consists of six criteria: selection bias, study design, confounders, blinding, data collection methods, and withdrawals and dropouts. Each study was appraised according to the six criteria and rated as “strong”, “moderate” or “weak” according to characteris- tics of each criterion reported in the study. Two reviewers independently scored all relevant articles for quality. Differences in scoring were resolved by discussion. The intent of the critical appraisal was to extract data from the methodologically strong and moderate studies; however, no strong studies were identified so only Page 3 of 14 moderate studies are included in this review. See Table 1 for the results of quality assessment of included stu- dies. For results of quality assessment of methodologi- cally weak studies [12-81], see Appendix B (additional file 2). For the characteristics of included studies see Table 2. The data were reported in a narrative format that included information on study design, interventions and outcomes. All statistically significant and non-signif- icant outcomes that were considered relevant to the review question were reported. When multiple articles reported different outcome measures on the same sam- ple, data from those articles were combined. Data were extracted by one reviewer and checked by a second reviewer to ensure accuracy. Results Quality and Categorization of Studies A total of 1546 unique articles were identified in the search and underwent title and abstract screening. Of those articles, 415 potentially relevant articles underwent Table 1 Quality Assessment Results for Methodologically Moderate Relevant Studies (n = 10) Confounders Blinding Data Collection Methods Withdrawals/ Dropouts Author/Date Forchuk, Maclure, Van Beers, Smith, Csiernik, Hoch et al., 2008 [82] Kushel, Colfax, Ragland, Heineman, Palacio, & Bangsberg, 2006 [101] Larimer, Malone, Garner, Atkins, Burlingham, Lonczak et al., 2009 [83] Milby, Schumacher, McNamara, Wallace, Usdan, McGill et al., 2004 Milby, Schumacher, Wallace, Frison, McNamara, Usdan et al., 2003 Milby, Schumacher, Vuchinich, Wallace, Plant, Freedman et al., 2004 [84-86] Milby, Schumacher, Wallace, Freedman & Vuchinich, 2005 Kertesz, Mullins, Schumacher, Wallace, Kirk & Milby, 2007 [87,88] Rotheram-Borus, Desmond, Comulada, Arnold, & Johnson, 2009 [97] Schwarcz, Hsu, Vittinghoff, Vu, Bamberger, & Katz, 2009 [98] Slesnick, Prestopnik, Meyers, & Glassman, 2008 Slesnick & Kang, 2008 [102,103] Tsemberis, Moran, Shinn, Armussen, & Shern, 2003 Padgett, Gulcur, & Tsemberis, 2006 Tsemberis, Gulcur, & Nakae, 2004 Gulcur, Tsemberis, Stefancic, & Greenwood, 2007 Greenwood, Schaefer-McDaniel, Winkel, & Tsemberis, 2005 Stefancic, Schaefer-McDaniel, Davis, & Tsemberis, 2004 [90-92,120-122] Wolitski, Kidder & Fenton, 2007 Kidder, Wolitski, Royal, Aidala, Courtenary-Quirk, Holtgrave et al., 2007 [123,124] Selection Bias Weak Study Design Strong Moderate Moderate Moderate Moderate Moderate Strong Moderate Strong Strong Moderate Moderate Strong Moderate Strong Strong Strong Strong Strong Strong Strong Strong Strong Moderate Weak Weak Moderate Moderate Strong Weak Weak Strong Strong Strong Strong Strong Weak Strong Strong Moderate Strong Strong Moderate Strong Weak Moderate Moderate Strong Strong Weak Strong Strong Moderate Global Rating Moderate Moderate Strong Strong Moderate Moderate Moderate Moderate Moderate Moderate Not Applicable Moderate Moderate Moderate Strong Moderate