Potential use of routine databases in health technology assessment.

OBJECTIVES To develop criteria for classifying databases in relation to their potential use in health technology (HT) assessment and to apply them to a list of databases of relevance in the UK. To explore the extent to which prioritized databases could pick up those HTs being assessed by the National Coordinating Centre for Health Technology Assessment (NCCHTA) and the extent to which these databases have been used in HT assessment. To explore the validation of the databases and their cost. DATA SOURCES Electronic databases. Key literature sources. Experienced users of routine databases. REVIEW METHODS A 'first principles' examination of the data necessary for each type of HT assessment was carried out, supplemented by literature searches and a historical review. The principal investigators applied the criteria to the databases. Comments of the 'keepers' of the prioritized databases were incorporated. Details of 161 topics funded by the NHS R&D Health Technology Assessment (HTA) programme were reviewed iteratively by the principal investigators. Uses of databases in HTAs were identified by literature searches, which included the title of each prioritized database as a keyword. Annual reports of databases were examined and 'keepers' queried. The validity of each database was assessed using criteria based on a literature search and involvement by the authors in a national academic network. The costs of databases were established from annual reports, enquiries to 'keepers' of databases and 'guesstimates' based on cost per record. For assessing effectiveness, equity and diffusion, routine databases were classified into three broad groups: (1) group I databases, identifying both HTs and health states, (2) group II databases, identifying the HTs, but not a health state, and (3) group III databases, identifying health states, but not an HT. Group I datasets were disaggregated into clinical registries, clinical administrative databases and population-oriented databases. Group III were disaggregated into adverse event reporting, confidential enquiries, disease-only registers and health surveys. RESULTS Databases in group I can be used not only to assess effectiveness but also to assess diffusion and equity. Databases in group II can only assess diffusion. Group III has restricted scope for assessing HTs, except for analysis of adverse events. For use in costing, databases need to include unit costs or prices. Some databases included unit cost as well as a specific HT. A list of around 270 databases was identified at the level of UK, England and Wales or England (over 1000 including Scotland, Wales and Northern Ireland). Allocation of these to the above groups identified around 60 databases with some potential for HT assessment, roughly half to group I. Eighteen clinical registers were identified as having the greatest potential although the clinical administrative datasets had potential mainly owing to their inclusion of a wide range of technologies. Only two databases were identified that could directly be used in costing. The review of the potential capture of HTs prioritized by the UK's NHS R&D HTA programme showed that only 10% would be captured in these databases, mainly drugs prescribed in primary care. The review of the use of routine databases in any form of HT assessment indicated that clinical registers were mainly used for national comparative audit. Some databases have only been used in annual reports, usually time trend analysis. A few peer-reviewed papers used a clinical register to assess the effectiveness of a technology. Accessibility is suggested as a barrier to using most databases. Clinical administrative databases (group Ib) have mainly been used to build population needs indices and performance indicators. A review of the validity of used databases showed that although internal consistency checks were common, relatively few had any form of external audit. Some comparative audit databases have data scrutinised by participating units. Issues around coverage and coding have, in general, received little attention. NHS funding of databases has been mainly for 'Central Returns' for management purposes, which excludes those databases with the greatest potential for HT assessment. Funding for databases was various, but some are unfunded, relying on goodwill. The estimated total cost of databases in group I plus selected databases from groups II and III has been estimated at pound 50 million or around 0.1% of annual NHS spend. A few databases with limited potential for HT assessment account for the bulk of spending. CONCLUSIONS Suggestions for policy include clarification of responsibility for the strategic development of databases, improved resourcing, and issues around coding, confidentiality, ownership and access, maintenance of clinical support, optimal use of information technology, filling gaps and remedying deficiencies. Recommendations for researchers include closer policy links between routine data and R&D, and selective investment in the more promising databases. Recommended research topics include optimal capture and coding of the range of HTs, international comparisons of the role, funding and use of routine data in healthcare systems and use of routine database in trials and in modelling. Independent evaluations are recommended for information strategies (such as those around the National Service Frameworks and various collaborations) and for electronic patient and health records.