The association between chronic kidney disease and tuberculosis; a comparative cohort study in England

Study type
Protocol
Date of Approval
Study reference ID
17_124
Lay Summary

Chronic kidney disease (defined as roughly half of normal kidney function) is a common condition in the general population. Previous studies suggest that decreased kidney function is associated with tuberculosis, partly because chronic kidney disease and tuberculosis have common risk factors such as smoking, socio-economic status, and diabetes mellitus. However, it is unknown whether chronic kidney disease is a risk factor for tuberculosis. Therefore, we will compare the proportion of patients with a history of tuberculosis diagnosis and the rate of new tuberculosis diagnosis between patients with and without chronic kidney disease in UK primary care data. Results would be useful to understand the burden of tuberculosis in patients with chronic kidney disease, and to discuss future healthcare-service planning for patients with chronic kidney disease.

Technical Summary

We will compare the prevalence and incidence of tuberculosis diagnosis between patients with and without chronic kidney disease (CKD). We will use a cohort of 242,349 matched pairs with and without CKD (estimated glomerular filtration rate <60 mL/min/1.73m2 twice for >3 months) for age, sex, general practice and calendar time between 2004 and 2014 in CPRD linked to Hospital Episode Statistics, which was established in our ongoing study (protocol 15_219RA). For prevalence, we will look at the tuberculosis diagnosis recorded any time after CPRD registration to the cohort entry (i.e. date of satisfying CKD definition for patients with CKD, and the same date for matched patients without CKD). For incidence, after excluding patients with a history of tuberculosis, we will compare the rate of newly diagnosed tuberculosis between patients with and without CKD. We will adjust for confounding factors including smoking and socio-economic status, ethnicity, BMI, comorbidities (e.g. diabetes) and prescription of oral corticosteroids in the logistic regression analysis for a history of tuberculosis and Poisson regression analysis for incident tuberculosis. We will look for evidence of interaction by age and ethnicity.

Collaborators

Dorothea Nitsch - Chief Investigator - London School of Hygiene & Tropical Medicine ( LSHTM )
Masao Iwagami - Corresponding Applicant - University of Tsukuba
Judith Ruzangi - Collaborator - Imperial College London
Liam Smeeth - Collaborator - London School of Hygiene & Tropical Medicine ( LSHTM )
Punam Mangtani - Collaborator - London School of Hygiene & Tropical Medicine ( LSHTM )

Linkages

HES Admitted Patient Care;Patient Level Index of Multiple Deprivation;Practice Level Index of Multiple Deprivation