A widening health gap in general practice? Socio-economic differences in morbidity between 1975 and 2000 in The Netherlands.

Background: During the past two decades, socio-economic inequalities in health have been a major research theme in Western Europe. Research has shown that there are persistent differences in health between people with a high socio-economic status (SES) compared with people with a low SES. There are also indications for a widening health gap. The present paper aimed to find out whether this widening health gap exists in The Netherlands using morbidity data from a general practice (GP) registry.

Methods: Incidence data from a GP registry were used, involving over 12,000 patients. Morbidity data from 1975 to 2000 were grouped into 25 disease categories. SES was based on household occupational status. Poisson regression was used to determine the relationship between morbidity and SES and its changes over time. Separate analyses were performed for men and women.

Results: In most disease categories, a clear SES gradient disadvantageous to the lowest-SES group was identified: 17 out of 22 morbidity categories for men and 17 out of 24 for women. For seven (men) and eight (women) morbidity categories out of 17, the SES gradient increased between 1975 and 2000.

Conclusions: This study provides new evidence for a widening gap in health between higher and lower SES in The Netherlands, using GP-defined disease data and a wide range of morbidity categories.