MULTIMETHOD APPROACH TO THE ASSESSMENT OF DATA QUALITY IN THE FINNISHMEDICAL BIRTH REGISTRY

Objective-To assess comprehensively the validity of the data in the Fi nnish Medical Birth Registry (MBR) by the combined use of several cont rols and internal analysis of the data. Design-The MBR data were indiv idually linked to a medical record sample (n=775) and to all perinatal death certificates in 1987. The data were also compared with annual h ospital statistics. The distributions of birth weights and gestational ages were examined. Subjects-All stillborn and liveborn babies regist ered in the MBR in 1987 (n=59 370). Setting-The nationwide MBR data we re compared with medical records from one third of the Finnish hospita ls, with statistics for all hospitals, and with nationwide cause of de ath registry data. Measurements and main results-With regard to most v ariables, the data quality was good or satisfactory (agreement with me dical records 95% or more). Allowing for minor deviations in variables with continuous scales improved the agreement rates further. Explanat ions could be deduced for items with poor agreement values. For most v ariables, the amount of missing data was less than 1%. With the except ion of caesarean sections, medical procedures were registered in only 30 to 72% of the cases, and the proportion varied strongly between the hospitals. Common diagnoses (32 to 86%) and primary causes of death ( 59 to 78%) were also poorly recorded. Conclusions-Combined use of seve ral control materials and internal analyses was successful in investig ating the whole data content. The data in the MBR were generally valid but diagnoses and most data on medical procedures were not of suffici ently good quality.