Health and social factors for health visitor caseload weighting: reliability, accuracy and current and potential use

The reliability and validity of data collection and recording for a health visitor caseload weighting system operating in a large combined acute and community trust in Bristol was examined. Client families were recruited from all participating (service) health visitors and were interviewed by a research health visitor attached to the project. The presence or absence of 28 health needs factors, selected for their known impact on health in the longer term, was subsequently compared with the service health visitor's own caseload records and with the computer record derived from them. Substantial differences were determined in the records obtained between the service and research health visitors and between the written and computerised records. Whilst the mean total score recorded for each family by the service health visitor was 2.0, the average of the differences in the total number of health factors recorded by the service and research health visitors was 1.9. Discrepancies were mostly associated with differences in interpretation of definitions, knowledge of recent events, changing circumstances and issues of confidentiality. Health factors at particular risk of being misinterpreted and those associated with other health factors were identified in order to propose a reduced factor set with greater inherent reliability and validity. At the level of the ward, the caseload weighting score, as currently defined, is highly correlated with standard deprivation indices in widespread common use. The results of this study indicate the need for users of the caseload weighting data to decide on the primary function of this data set - area-based community profiling or identification of at-risk client families in the community. This decision will inform further efforts to identify the most useful factors, tighten definitions, streamline data collection and train health visitors in their use. Interpretation of data will be facilitated by a scientifically developed scoring system. This work will assist trusts, both locally and nationally, in rationalising their allocation of health visiting activities to areas of greatest need.