The South African national non-natural mortality surveillance system - rationale, pilot results and evaluation
Background. While individual mortuaries have recorded data for non-natural deaths in time-limited studies, there have been no systematic efforts to draw forensic-medical services and state mortuaries into a nationwide fatal injury surveillance system. Beginning in June 1998, the National Non-Natural Mortality Surveillance System (NMSS) commenced pilot operation.
Objective. To evaluate the NMSS and illustrate its utility from sample findings.
Design. Data entered into the system by mortuary staff were checked against a random sample of cases for which separate forms were completed by an independent researcher. Process observations and follow-up with data users were used to assess the system's acceptability, timeliness and data usefulness.
Setting. Eighteen mortuaries in six provinces representing approximately 35 000 cases per year, or around 50% of all non-natural deaths.
Participants. The National Departments of Health; Safety and Security; and Arts, Culture, Science and Technology; national and provincial forensic medico-legal services; the South African Police Services; universities and science research councils.
Main outcome measures. Surveillance system simplicity, flexibility, acceptability, sensitivity, positive predictive value, representativeness, timeliness, data usefulness and resources.
Results. The NMSS was established at 10 target sites. Lack of equipment, personnel resistance, and closure of some mortuaries prevented implementation in the remaining eight mortuaries. Sensitivity was internally assessed and ranged from 65% to 95% for manner of death. Positive predictive value was also internally measured, and ranged from 74% to 80% for manner of death and from 71% to 82% for mechanism of death. Timeliness was good, and basic reports covering most items were available 6 weeks after a case had been examined. While staff found the system simple, acceptability depended on the individuals involved at different mortuaries, and the system was compromised to some extent by bureaucratic barriers. End users found the data to be of great value. NMSS set-up costs totalled approximately R26 000 per mortuary, and it is estimated that maintenance costs will be R8.00 per case registered.
Conclusions. With minimal resources, the NMSS uses existing investigative procedures to describe and report the epidemiology of fatal injuries. The pilot study demonstrates the feasibility of the system, and identifies the need to remove organisational constraints and individual barriers if it is to be sustained and expanded beyond the pilot sites.