Abstracts: ISEE 21st Annual Conference, Dublin, Ireland, August 25-29, 2009: Oral Presentations
The available evidence for a link between socioeconomic status (SES) and congenital anomalies is very limited and is mostly based on individual level SES. Our study aimed to investigate the association between the occurrence of non-chromosomal congenital anomalies and neighborhood SES at fine spatial resolution.
We used population-based registry data on all cases of congenital anomaly arising in the population of Northern England (UK) for the period 1986-2003. Two sub-analyses were performed using the Townsend Deprivation Score (TDS) at Enumeration District level (ED, 1991 census) for the period 1986-1996 and the Index of Multiple Deprivation (IMD) at lower layer super output area level (LSOA, 2001 census) for the period 1997-2003. Congenital anomaly cases occurring in each sub-analysis period were geocoded according to the maternal postcode at delivery and assigned to the corresponding ED/LSOA. The count of cases for anomalies of eight organ systems and the 15 most frequent anomaly subtypes were extracted for each ED/LOSA. Poisson and logistic regression models were developed to abstract risk for quartiles of TDS/IMD at ED/LSOA level for each outcome group in each sub-analysis.
There were 6,202 EDs and 1,869 LSOAs with average populations of 454 and 1,513. For most outcome groups there was a trend in congenital anomaly risk with deprivation when assessed by quartiles of TDS/IMD, with a significant increase in risk in the fourth quartile (most deprived) compared with the first quartile (least deprived).
The occurrence of congenital anomalies is associated with neighborhood SES. The results of our study are important for epidemiological studies relying on routinely-collected aggregated measures of SES to investigate the non-genetic causes of congenital anomalies. It emphasizes the importance of allowing for the impact of SES in these studies or to proximate the effect of possible confounders for which data are not always available.