Hospitalized prevalence and 5-year mortality for IBD: record linkage study

Abstract

Aim: To establish the hospitalized prevalence of severe Crohn's disease (CD) and ulcerative colitis (UC) in Wales from 1999 to 2007; and to investigate long-term mortality after hospitalization and associations with social deprivation and other socio-demographic factors.

Methods: Record linkage of administrative inpatient and mortality data for 1467 and 1482 people hospitalised as emergencies for > or = 3 d for CD and UC, respectively. The main outcome measures were hospitalized prevalence, mortality rates and standardized mortality ratios for up to 5 years follow-up after hospitalization.

Results: Hospitalized prevalence was 50.1 per 100 000 population for CD and 50.6 for UC. The hospitalized prevalence of CD was significantly higher (P < 0.05) in females (57.4) than in males (42.2), and was highest in people aged 16-29 years, but the prevalence of UC was similar in males (51.0) and females (50.1), and increased continuously with age. The hospitalized prevalence of CD was slightly higher in the most deprived areas, but there was no association between social deprivation and hospitalized prevalence of UC. Mortality was 6.8% and 14.6% after 1 and 5 years follow-up for CD, and 9.2% and 20.8% after 1 and 5 years for UC. For both CD and UC, there was little discernible association between mortality and social deprivation, distance from hospital, urban/rural residence and geography.

Conclusion: CD and UC have distinct demographic profiles. The higher prevalence of hospitalized CD in more deprived areas may reflect higher prevalence and higher hospital dependency.

Figure 1

WIMD 2005 quintiles for the 22 health boards and the 1896 geographical LSOAs in Wales. The key to the health board numbering is as follow: 1 Blaenau Gwent; 2 Bridgend; 3 Caerphilly; 4 Cardiff; 5 Carmarthenshire; 6 Ceredigion; 7 Conwy; 8 Denbighshire; 9 Flintshire; 10 Gwynedd; 11 Isle of Anglesey; 12 Merthyr Tydfil; 13 Monmouthshire; 14 Neath Port Talbot; 15 Newport; 16 Pembrokeshire; 17 Powys; 18 Rhondda Cynon Taff; 19 Swansea; 20 Torfaen; 21 The Vale of Glamorgan; 22 Wrexham.

Figure 2

Hospitalized prevalence of severe Crohn’s disease and ulcerative colitis according to social deprivation, 1999-2007. I: Least deprived social deprivation quintile; V: Most deprived. Vertical bars represent 95% CI. These prevalence rates are standardised for age group and gender.