Herpes zoster, also known as shingles, is a frequent skin infection caused by reactivation of varicella zoster virus (VZV), which lies latent in the sensory ganglia after the primary infection chickenpox. Reactivation of the virus occurs when the immunity towards VZV wanes below a certain critical level. An increased risk of herpes zoster is thus observed among patient with immunosuppression, including those with inherited immunodeficiency and immunosuppression induced by drugs (e.g. chemotherapy), radiotherapy, or other disease (e.g. human immunodeficiency virus [HIV] or cancer).
Psychological stress may result in suppression of the immune system and thus possibly an increased risk of herpes zoster. However, data from large epidemiological studies on psychological stressors as risk factors for herpes zoster are sparse and conflicting.
Using data from the UK Clinical Practice Research Datalink (CPRD) and Hospital Episode Statistics (HES), we will investigate whether individuals diagnosed with herpes zoster have more frequent history of psychological stress than individuals without zoster, including partner bereavement, depressive disorder, anxiety disorder, and stress or adjustment disorder. We will explore the impact of recentness and severity of stress. Data will be published together with results from parallel analyses conducted on Danish data. The study is a health research study.
We will use CPRD and HES data to conduct a case-control study of the association between psychological stress and the risk of herpes zoster.
We will identify all adults with a first-time diagnosis of herpes zoster between 2000 to 2014. We will use incidence density sampling to select four controls per case matched by age, sex and practice. The date of herpes zoster diagnosis will be considered the index date for cases and their matched controls.
We will identify history of partner bereavement, depressive disorder, anxiety disorder, and stress or adjustment disorder prior to index date. We will categorise bereavement according to whether the partner death was foreseen, as measured by the age-adjusted Charlson Comorbidity Index and codes indicating terminal disease. For the psychiatric diagnoses, we will categorise severity as severe (requiring inpatient admission), moderate (requiring referral to other mental health service) or mild (remaining patients) based on healthcare records within 90 days before index date.
Using conditional logistic regression, we will compute odds ratios with 99% confidence intervals for the association between each psychological stressor and herpes zoster adjusting for risk factors for herpes zoster. We will examine the robustness of our results through several sensitivity analyses.
Sinead Langan - Chief Investigator - London School of Hygiene & Tropical Medicine ( LSHTM )
Sigrún Alba Jóhannesdóttir Schmidt - Corresponding Applicant - Aarhus University Hospital
Harriet Forbes - Collaborator - London School of Hygiene & Tropical Medicine ( LSHTM )
Henrik Carl Schonheyder Pedersen - Collaborator - Aalborg University Hospital
Henrik Carl Schonheyder Pedersen - Collaborator - Aalborg University Hospital
Henrik Toft Sorensen - Collaborator - Aarhus University
Kathryn Mansfield - Collaborator - London School of Hygiene & Tropical Medicine ( LSHTM )
Liam Smeeth - Collaborator - London School of Hygiene & Tropical Medicine ( LSHTM )
Mogens Vestergaard - Collaborator - Aarhus University
Sara Thomas - Collaborator - Not from an Organisation
HES Admitted Patient Care;Patient Level Index of Multiple Deprivation;Practice Level Index of Multiple Deprivation