OBJECTIVES: Deriving data on clinical outcomes to populate economic models requires a series of key decisions upon the part of the economist. Ideally, to minimise the potential for bias, the process of including data should be systematic. The objective of this research is to construct a quality assessment checklist for the inclusion of clinical and epidemiological data in economic models, and furthermore to illustrate its application in the area of osteoporosis, where economic evaluations predominantly take the form of decision-analytical models. METHODS: A systematic review involving electronic databases and hand-searches was conducted of full economic evaluations of interventions in osteoporosis. The included studies were assessed using a checklist based on the Cochrane Collaboration handbook for systematic reviews. The six main items of the checklist included the (i) specification of the research question, (ii) comprehensiveness of the literature review, (iii) critical appraisal of studies, (iv) relevance of the data extraction, (v) appropriateness of the analysis and (vi) handling of uncertainty. RESULTS: 18 studies met the criteria for inclusion (UK= 6, US=7, Australia=2). 16 studies considered hormone replacement therapy, 3 calcitonin, 2 calcium and 2 bisphosphonates. It was found that 28% satisfied 4 or more of the six main criteria. It was also found that only 33% studies did a comprehensive literature review; primary studies were predominantly epidemiological, but only 4 appraised the quality of the observational data. CONCLUSION: These results demonstrate methodological weaknesses in the process of including data in osteoporosis models. Quality checklists for economic models should therefore emphasise the identification, retrieval, extraction and pooling methods for the clinical outcome data. Further there should be increased transparency in the reporting of economic models to assist in model quality assessment and validation. Future research should focus on the impact of biased data selection on cost effectiveness ratios.