Bereavement amongst those with chronic kidney disease - does it affect outcomes?

Date of ISAC Approval: 
13/03/2019
Lay Summary: 
People living with chronic kidney disease (CKD) are at higher risk of a number of outcomes, including myocardial infarction, acute kidney injury, and death. Risk factors for these outcomes, such as infections and other co-morbidities, have been studied in this population; however, one potential risk factor that has still not been studied is bereavement. The period following the death of a loved one has been shown to be associated with a substantially higher risk of sudden-onset illness and death, particularly in men and those at high cardiovascular risk at a younger age. There are currently no data on how those living with kidney disease are affected by this type of stress. We will study the risk of acute cardiovascular events, acute kidney injury, and death in a cohort of people with CKD experiencing bereavement compared to CKD patients not experiencing bereavement. Results of this analysis could inform future studies examining interventions to reduce a possible increased risk of complications in people with chronic kidney disease experiencing acute periods of stress, particularly during bereavement.
Technical Summary: 
Bereavement is a known risk factor for a variety of poor cardiovascular outcomes and death. To our knowledge, there are no studies which have assessed the impact partner bereavement may have on cardiovascular and kidney outcomes specifically in patients with pre-existing chronic kidney disease (CKD). This study will be designed as a matched historical cohort study to investigate a possible association between partner bereavement and an increased risk of cardiovascular events, acute kidney injury, and death in people with CKD. This study will use primary care data from the Clinical Practice Research Datalink (CPRD) linked to Hospital Episode Statistics (HES) and Office for National Statistics (ONS) data to determine exposure, outcome, and confounder statuses in our study population. Partners will be identified in the CPRD using the family number and restricted to those with CKD, whilst maintaining de-identification of individual patient data. The exposure of interest is partner bereavement in patients with CKD. Each bereaved (exposed) individual will then be matched with up to 10 other people with CKD based on age, sex, and general practice. Matched unexposed patients must be alive at the exposed person's index date of bereavement but have never experienced partner bereavement before the index date. Time-to-event analyses (either Poisson or Cox models, depending on the shape of the relative hazards over time) will be used to investigate crude and adjusted associations of bereavement with CVD outcomes, AKI, and death. Crude and adjusted hazard ratios and 95% confidence intervals will be used to measure any possible associations between bereavement and adverse outcomes in the study population.
Health Outcomes to be Measured: 
- Incident cardiovascular events (myocardial infarction), acute heart failure, and stroke - Incident acute kidney injury - Death
Collaborators: 

Dr Dorothea Nitsch - Chief Investigator - London School Of Hygiene & Tropical Medicine (LSHTM)
Professor Christian Christiansen - Collaborator - Aarhus University Hospital
Professor Liam Smeeth - Collaborator - London School Of Hygiene & Tropical Medicine (LSHTM)
Patrick Bidulka - Corresponding Applicant - London School Of Hygiene & Tropical Medicine (LSHTM)
Sigrun Alba Johannesdottir Schmidt - Collaborator - Aarhus University Hospital
Sinead Langan - Collaborator - London School Of Hygiene & Tropical Medicine (LSHTM)
Dr Soren Vestergaard - Collaborator - Aarhus University Hospital
Dr Yochai Schonmann - Collaborator - London School Of Hygiene & Tropical Medicine (LSHTM)
Yun "Angel" Wong - Collaborator - London School Of Hygiene & Tropical Medicine (LSHTM)

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