Birth Distance Influential Factors: A Multilevel Recurrent Events Approach

Background: The study was developed in order to find a subset of potential factors, which affect birth distance pattern, regarding consideration on correlation of events of birth in a family and correlation within clusters/centers which other studies omit these correlations. Methods: Referring to documents that were registered for family in the health care centers on socio-economical zone, we consider the families with at least one successful birth. Data were drawn from four health care centers, which selected via 27-health center in Hamedan City, western Iran, each from a socio-economic zone. It was expected, same socio-economic status family have same specific birth distance and a family follows a specific pattern. The multilevel recurrent approach was conducted to analyze the sample. The sample was 480 families and 1115 birth events occurred in these families. Results: The final step model shows that significant factors on the birth distance time were mothers job (P=0.018). The random effect of second level (clusters/centers) was significant (P=0.038). In other words, the socio-economic of family affects on the birth distance patterns. Other potential variables were not significantly affected birth distances and were deleted from the final model. Conclusions: There are many potential factors, which may affect to birth distance, but multilevel recurrent event model has a better fit to data because of frailty and center effects. Application of other model such as Cox and frailty models may result in misleading reports.