Oped (T.M.) for the following sources from inception to August 2011: Ovid MEDLINE, Embase, PubMed, CINAHL via Ebsco, Cochrane Central Register of Controlled Trials (Central), Scopus, Proquest, Web of Knowledge, Google and Google Scholar. Subsequently, a qualified and experienced information professional (A.B.) constructed a series of supplementary search strategies and methods to validate the initial retrieval set and to extend data coverage until December 2011. This process, which involved subject searching of MEDLINE and Web of Science and citation searches for included studies on Web of Table 1. SPICE formulation for the question.Data extractionInitial data extraction was conducted independently, using a standardized form (T.H) and then verified by a second reviewer (A.B.). Subsequent tabulation was verified by a third investigator (H.B.T.). Data abstractors collected information about the study setting, study populations, sample size, dosage, and any mechanisms for ensuring adherence. Our primary interest was in verbatim responses from informants on barriers to their adherence with isoniazid preventive therapy. However we were also interested in patient responses to pre-identified factors, for example in structured surveys or questionnaires. For triangulation purposes only we also decided to include reports from health personnel when in direct contact with patients and who, therefore, had perceptions on reasons for adherence/non-adherence. However these were treated as “indirect evidence” only and, therefore, were not used to direct our initial conceptual model. We applied the Critical Appraisal Skills Programme (CASP) checklist for qualitative studies, as adapted by Hawker and colleagues, since it can also be used in studies where disparate data are involved [16]. The nine detailed questions were answered according to the responses; Good, Fair, Poor and Very Poor to arrive at an overall qualitative judgement on study quality.Data synthesisSeveral Quinagolide (hydrochloride)MedChemExpress Quinagolide (hydrochloride) alternative methods exist for synthesis of qualitative data. Where studies contain conceptually-rich data and the objective is to improve theoretical understanding, more interpretative methods, such as meta-ethnography, are available. However, the output of some methods of synthesis, (e.g. thematic synthesis and framework synthesis), is considered more directly relevant to policymakers and designers of interventions than outputs from methods with a more constructivist orientation (e.g. meta-ethnography) which are generally more “complex and conceptual” [17]. Thematic synthesis is analogous to methods of primary analysis of qualitative data such as thematic analysis, using AC220MedChemExpress Quizartinib techniques to formalize the identification and development of themes [18]. Such themes can be explored both individually and in terms of their inter-relationships with each other. Thematic synthesis was therefore used to analyse factors relating to adherence with isoniazid preventive therapy in people living with HIV/AIDS.Setting(s): Hospital or clinics administering IPT Perspective: People living with HIV/AIDS (PLWHA) Intervention: Isoniazid preventive treatment Comparison: None Evaluation: Factors that contribute to IPT adherence doi:10.1371/journal.pone.0087166.tPLOS ONE | www.plosone.orgAdherence to Isoniazid Preventive TherapyResultsFigure 1 shows the flow diagram of study selection for analysis. Furthermore, the nine studies excluded at the final stage of the selection process, after assessment of the full text.Oped (T.M.) for the following sources from inception to August 2011: Ovid MEDLINE, Embase, PubMed, CINAHL via Ebsco, Cochrane Central Register of Controlled Trials (Central), Scopus, Proquest, Web of Knowledge, Google and Google Scholar. Subsequently, a qualified and experienced information professional (A.B.) constructed a series of supplementary search strategies and methods to validate the initial retrieval set and to extend data coverage until December 2011. This process, which involved subject searching of MEDLINE and Web of Science and citation searches for included studies on Web of Table 1. SPICE formulation for the question.Data extractionInitial data extraction was conducted independently, using a standardized form (T.H) and then verified by a second reviewer (A.B.). Subsequent tabulation was verified by a third investigator (H.B.T.). Data abstractors collected information about the study setting, study populations, sample size, dosage, and any mechanisms for ensuring adherence. Our primary interest was in verbatim responses from informants on barriers to their adherence with isoniazid preventive therapy. However we were also interested in patient responses to pre-identified factors, for example in structured surveys or questionnaires. For triangulation purposes only we also decided to include reports from health personnel when in direct contact with patients and who, therefore, had perceptions on reasons for adherence/non-adherence. However these were treated as “indirect evidence” only and, therefore, were not used to direct our initial conceptual model. We applied the Critical Appraisal Skills Programme (CASP) checklist for qualitative studies, as adapted by Hawker and colleagues, since it can also be used in studies where disparate data are involved [16]. The nine detailed questions were answered according to the responses; Good, Fair, Poor and Very Poor to arrive at an overall qualitative judgement on study quality.Data synthesisSeveral alternative methods exist for synthesis of qualitative data. Where studies contain conceptually-rich data and the objective is to improve theoretical understanding, more interpretative methods, such as meta-ethnography, are available. However, the output of some methods of synthesis, (e.g. thematic synthesis and framework synthesis), is considered more directly relevant to policymakers and designers of interventions than outputs from methods with a more constructivist orientation (e.g. meta-ethnography) which are generally more “complex and conceptual” [17]. Thematic synthesis is analogous to methods of primary analysis of qualitative data such as thematic analysis, using techniques to formalize the identification and development of themes [18]. Such themes can be explored both individually and in terms of their inter-relationships with each other. Thematic synthesis was therefore used to analyse factors relating to adherence with isoniazid preventive therapy in people living with HIV/AIDS.Setting(s): Hospital or clinics administering IPT Perspective: People living with HIV/AIDS (PLWHA) Intervention: Isoniazid preventive treatment Comparison: None Evaluation: Factors that contribute to IPT adherence doi:10.1371/journal.pone.0087166.tPLOS ONE | www.plosone.orgAdherence to Isoniazid Preventive TherapyResultsFigure 1 shows the flow diagram of study selection for analysis. Furthermore, the nine studies excluded at the final stage of the selection process, after assessment of the full text.