Suicides may be overreported and accidents underreported among fatalities due to dextropropoxyphene

Among prescribed drugs in Sweden dextropropoxyphene (DXP) is the medical compound most frequently responsible for self-inflicted fatal poisonings. To analyze the process leading to the classification of the manner of death in cases of fatalities where DXP caused or contributed to death, a set of explicit and implicit operational criteria was applied retrospectively to fatal DXP poisonings among autopsy cases performed at one department of forensic medicine in Sweden during the six-year period from 1992 to 1997. DXP fatality was found in 113 (2.6%) of the total 4306 autopsy cases. Suicide was recorded in 84 (74%) of these cases, and an undetermined manner of death in 24 (21%). Explicit unambiguous expressions of the intent of the decedent were found in 29 (26%) of the 109 analyzed cases. (In four cases no analysis could be performed). In 46 cases only implicit and no explicit criteria were found. The total number of implicit criteria in individual cases without explicit criteria never exceeded three and in 34 cases no criteria of any type were documented. It is concluded that the classification of the manner of death at DXP fatalities was often based on very limited grounds when the operational criteria were used as a standard for comparison. Information from relatives, friends and others concerning the decedent was rarely accessible. The shortage of information probably led to deficiencies in the death statistics concerning DXP fatalities. Considerable underreporting of accidents and probable overreporting of suicides were found. Failure to report DXP deaths as accidents may delay discovery of the high toxicity of this drug. This might be one of the reasons why the DXP fatality rate is still constantly high in Sweden, while both Denmark and Norway have managed to decrease their DXP death rates by vast restrictions, based on alarming reports of accidental DXP fatalities. In order to guarantee valid death statistics concerning self-inflicted poisoning, the information base leading to classification of the manner of death has to be enlarged. This requires implementation of new routines, including interviews of relatives, acquaintances and significant others to get the information needed to assess the decedent's intention to die. Operational criteria may facilitate the difficult classification process by providing a structured standard, and the set of explicit and implicit criteria applied in this study is recommended.