Table 1.

Processes for ensuring rigour of case-study research

Research Phase	Principles for Ensuring Rigour*	Methods Used in this Study
Design	Guiding conceptual theory or framework	Conceptual framework adapted from previous work of Sheikh et al. (2011), and theories of power and trust in health-care settings. Theory used in case selection triangulation (see below).
Data collection	Justified Case selection	Four health centres selected based on assumptions that interaction between system hardware & software will differ for health centres in urban, peri-urban and rural settings. Selection of centres from single province was based on timing of HIV service scale-up.
	Multiple methods	For each health centre: key informant interviews with staff; in-clinic observations; patient interviews; interviews with administrators and implementing partners.
	Sampling	Smaller health centres included interviews with all staff & approximately 45 patients.
		Larger health centres included interviews with representative sample of staff from each dept & approximately 45 patients.
	Prolonged engagement	Case: 2-3 weeks in each facility.
		Respondents: At least one formal interview with respondents and informal engagement over several weeks pre-/post-interview.
Analysis	Triangulation	Within case: Initial case reports based on triangulation across all data sets for each case (critical comparison of observation & interview findings), generating overall judgements about facility-wide experience & notes on variation in health-centre cases.
		Cross-case: Initial case reports generated to look for common and differing experiences across sites, and subsequently compared with theory to assess convergence or divergence.
	Negative Case analysis	Within case: Identification of experiences that contradicted initial assumptions, drawing on notes from initial case-data triangulation.
		Across-case: cross-case analysis to compare negative cases and test initial assumptions underpinning the study.
	Peer Debriefing & Support	Preliminary case reports reviewed by four colleagues (non-government, government & community-sector) working in Zambian health sector.
	Respondent validation	Preliminary cross-case analysis presented for review and comment to select respondents (clinic managers and provincial officials); feedback incorporated into final analysis.

*Source: Gilson et al.(2011).