Epidemiology of Munchausen syndrome by proxy in New Zealand

To determine the epidemiology of Munchausen syndrome by proxy (MSBP) in New Zealand and describe the effects of this condition on children and their paediatricians.

A mail-out survey was sent to all paediatricians in New Zealand in 1999. Paediatricians were asked to identify all cases of MSBP, non-accidental poisoning or non-accidental suffocation diagnosed or suspected in children less than 16 years of age that had been seen in the past 12 months. Those paediatricians who identified a case were then interviewed by telephone to ensure that identified cases were new cases and that they were unique.

Responses were obtained from 148 (95%) of 156 practising paediatricians in New Zealand. Eighteen unique cases of MSBP were identified where the diagnosis had been made in the preceding 12 months. The incidence rate for MSBP in children aged less than 16 years was 2.0/100 000 children. Eleven (61%) of the 18 cases were referred to child protection agencies or the police. The mean time taken to diagnosis from initial presentation was 7 months in the cases referred to child protection agencies and 23 months in cases not referred. The median age at diagnosis was 2.7 years. The mother was the suspected perpetrator in all cases. Most children (72%) presented with multiple symptoms. Over half (55%) had an underlying chronic illness. The morbidity for the child in the majority of cases was not severe, and in nine (50%) cases it was noted that following diagnosis there was improvement or resolution of symptoms. Ten (56%) of the 18 paediatricians involved with cases reported experiencing considerable stress.

The annual incidence in New Zealand of MSBP in children under 16 years is higher than that reported from other countries. Chronic illness is often associated with this condition. The morbidity for the majority of children was not severe and often improved with diagnosis. Paediatricians reported stress and difficulty in association with caring for children with this syndrome of child abuse.