Risk of hospitalization and death due to infection in people with psoriasis: a population-based cohort study using the Clinical Practice Research Datalink

Background Psoriasis is associated with risk factors for serious infections, but the independent relationship between psoriasis and serious infection is as yet unclear. Objectives To determine whether people with psoriasis have a higher risk of hospitalization due to any infection, respiratory infections, soft-tissue and skin infections, or a higher risk of death due to infection. Methods We conducted a cohort study of people (>= 18 years) with psoriasis using the UK Clinical Practice Research Datalink (CPRD GOLD) linked to Hospital Episode Statistics (HES) and Office for National Statistics (ONS) mortality records between 1 April 2003 and 31 December 2016, and matched with up to six comparators on age, sex and general practice. Hospitalization was ascertained from HES records; death was ascertained from ONS mortality records. Stratified Cox proportional hazard models were estimated, with stepwise adjustment in different models for potential confounders or mediators between psoriasis and serious infection. Results There were 69 315 people with psoriasis and 338 620 comparators who were followed up for a median (interquartile range) of 4 center dot 9 (5 center dot 9) and 5 center dot 1 (6 center dot 3) years, respectively. People with psoriasis had a higher incidence rate of serious infection [20 center dot 5 per 1000 person-years, 95% confidence interval (CI) 20 center dot 0-21 center dot 0, n = 7631] compared with those without psoriasis (16 center dot 1 per 1000 person-years, 95% CI 15 center dot 9-16 center dot 3, n = 30 761). The fully adjusted hazard ratio for the association between psoriasis and serious infection was 1 center dot 36 (95% CI 1 center dot 31-1 center dot 40), with similar results across the other outcomes. Conclusions Psoriasis is associated with a small increase in the risk of serious infection. Further research is needed to understand how psoriasis predisposes to a higher risk of infection.

Automated summary

The study found that patients with psoriasis have a higher incidence rate of serious infection, as well as other infection-related risks. Further research is needed to understand how psoriasis predisposes to a higher risk of infection.