Morbidity among HIV-positive people in England: a cross-sectional, population-based CALIBER study

Date of ISAC Approval: 
27/10/2015
Lay Summary: 
Well over one hundred thousand people in the UK have Human Immunodeficiency Virus (HIV) infection. But in just two decades, this once deadly infection has become a manageable chronic condition. Owing to advances in treatment, most HIV-positive people can expect to live for many years. Around a quarter are now aged over 50 years. On the down-side, it is known that people with HIV are at higher risk of heart disease than people without, and recently, international studies reported that HIV-positive people also have higher rates of other health problems including diabetes, asthma, liver and kidney failure. Despite the large numbers with HIV in the UK, we do not know if the same is true here. In this study, we will find out by comparing the health of people with and without HIV who live in England. We will investigate if people with HIV develop other illnesses earlier, or have more illnesses, compared with those not infected. Should either be the case, then both patients themselves and the National Health Service will be in a position to plan for future care. Our findings will make it possible to plan the best care possible.
Technical Summary: 
We wish to describe the prevalence of morbidities and of multi-morbidity (two or more morbidities other than HIV) among HIV-positive people living in England and to compare the prevalence rates with those among age- and sex-matched HIV-negative controls. To do so, we will undertake a retrospective observational cohort study. Using the CPRD and Hospital Episode Statistics (HES) data, individuals with diagnoses of HIV infection will be identified as will a comparator non-HIV-positive cohort in a ratio of 4:1 to the HIV-positive cohort. Economic and social data will be obtained and linked from the Office of National Statistics The cohorts will be matched for sex, age-group, and Index of Multiple Deprivation quintile. Using validated algorithms, we will identify in both cohorts the presence of nine morbidities [diabetes, congestive heart failure, acute myocardial infarction, hypertension, asthma, chronic obstructive lung disease, stroke, renal disease, peripheral vascular disease] and of multi-morbidity (two or more morbidities other than HIV). Morbidities will be identified by their relevant Read (CPRD) and ICD-10 (HES) codes. For individual morbidities and for multi-morbidity, we will calculate the cohort prevalence ratios with 95% confidence intervals. Sex, age-group, and Index of Multiple Deprivation quintile will be described as categorical variables and compared between the cohorts using chi-squared tests.
Health Outcomes to be Measured: 
Identification of morbidities; Asthma, Chronic Obstructive Lung Disease, Diabetes, Heart Failure, Hypertension, Myocardial Infarction, Peripheral Vascular Disease, Renal Disease, Stroke in patients with and without HIV.
Collaborators: 

Patricia McGettigan - Chief Investigator - Queen Mary University of London
Marina Daskalopoulou - Collaborator - University College London (UCL)
Nashaba Matin - Collaborator - Royal London Hospital
Patricia McGettigan - Corresponding Applicant - Queen Mary University of London
Spiros Denaxas - Collaborator - University College London (UCL)

Linkages: 
HES Admitted;ONS;Patient IMD;Practice IMD (Standard)