A UK general practice database study of prevalence and mortality of peoplewith neural tube defects

Objective: To investigate the prevalence of neural tube defects (NTDs) in t he UK and to compare the mortality rate with that of the general population . Methods: A cross-sectional study. The General Practice Research Database (G PRD) contains the prescribing and diagnostic records since 1990 of over 4 m illion people from throughout the UK. All patients aged 10-69 and registere d on the database in the years 1994-1997 were included in the study. Patien ts with a diagnosis of NTD were identified from the database and prevalence and standardized mortality ratios in each year were calculated. Results: The size of the GPRD reduced during the study period - there were 2116 452 patients aged 10-69 years on the database in 1994, of whom 1751 ha d a prior record of NTD. In 1997 there were 998 368 patients, of whom 842 h ad an NTD. The age standardized prevalence between 1994 and 1997 for NTDs r anged between 7.8 and 8.4 per 10 000 for males and 9;0 and 9.4 per 10 000 f or females aged 10-69 years. There were 27 deaths in patients with a record of NTD over the four-year study period. The standardized mortality ratio f or the years 1994 to 1997 for NTDs ranged between 1.9 and 2.9. Conclusions: These data give an estimate of the prevalence of NTDs in the g eneral population. They also show that those who have survived to age 10 ye ars still have double the mortality of the general population.