Increases in the completeness of disease records in dairy databases following changes in the criteria determining whether a record counts as correct
1 Department of Large Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Grønnegårdsvej 8, Copenhagen, Denmark
2 Department of Production Animal Clinical Science, Norwegian School of Veterinary Science, P.O. Box 8146 Dep, Oslo, NO-0033, Norway
3 Department of Clinical Sciences, Swedish University of Agricultural Sciences, P.O. Box 7054, Uppsala, SE-750 07, Sweden
4 Department of Veterinary Biosciences, University of Helsinki, P.O. Box 66, Helsinki, FI-00014, Finland
5 Department of Animal Science, Aarhus University, Blichers Allé 20, Tjele, DK-8830, Denmark
Acta Veterinaria Scandinavica 2012, 54:71 doi:10.1186/1751-0147-54-71Published: 3 December 2012
The four Nordic countries: Denmark (DK), Finland (FIN), Norway (NO) and Sweden (SE), all have national databases in which mainly records of treated animals are maintained. Recently, the completeness of locomotor disorder records in these databases has been evaluated using farmers’ recordings as a reference level. The objective of the present study was to see how previous estimates of completeness figures are affected by the criteria determining whether a recording in the database is to be judged correct. These demands included date of diagnosis and disease classification. In contrast with the previous study, a period of time between the date of disease recording in the database and by the farmer was allowed. Further, the calculations were brought to bear on individual locomotor diagnoses instead of a common locomotor disease complex code.
Randomly selected dairy herds (≥ 15 cows) were invited to participate. During two 2-month periods in 2008 the farmers recorded the diseases they observed on the farm and their recordings constituted a farmer database (FD). These recordings were compared to disease recordings in the National Databases (ND). Earlier calculations of completeness for locomotor complex cases assuming an exact match on date were compared with ±7 day and ±30 day discrepancies calculated in this study.
The farmers in DK, FIN, NO and SE recorded 426, 147, 97 and 193 locomotor disorders, respectively. When a window of ±7 days was allowed there was a relative increase in completeness figures lying in the range of 24–100%. Further increases were minor, or non-existent, when the window was expanded to ±30 days. The same trend was seen for individual diagnoses.
In all four of the Nordic countries a common pattern can be observed: a further increase in completeness occurs when individual locomotor diagnoses recorded by the farmer are permitted to match any locomotor diagnosis recorded in the ND. Completeness increased when both time span and different diagnoses within the locomotor complex were allowed.