Risk of Herpes Zoster in individuals diagnosed with COVID19 infection in the Valencia region of Spain: a retrospective cohort population-based study (AIV_HZ_2021_05_COVIDHZ_AOS)

Study type

• Study type:
  Non-interventional study
• Scope of the study:
  Assessment of risk minimisation measure implementation or effectiveness

  Disease epidemiology

Non-interventional study

• Non-interventional study design:
  Cohort

Study drug and medical condition

• Medical condition to be studied:
  Herpes zoster

  SARS-CoV-2 test positive

Population studied

• Age groups:
  • Adult and elderly population (≥18 years)

    • Adults (18 to < 65 years)

      • Adults (18 to < 46 years)
      • Adults (46 to < 65 years)
    • Elderly (≥ 65 years)

      • Adults (65 to < 75 years)
      • Adults (75 to < 85 years)
      • Adults (85 years and over)
• Special population of interest:
  Renal impaired

  Hepatic impaired

  Immunocompromised
• Estimated number of subjects:
  4000000

Study design details

• Main study objective:
  Compare the risk of HZ among individuals 50 years and older with and without laboratory confirmed SARS-CoV2 infection. Compare the risk of HZ among individuals 18 years and older with and without laboratory confirmed SARS-CoV2 infection. Compare the risk of HZ in overall population older than 18 years old in the pandemic period against pre-pandemic period.
• Outcomes:
  Compare the risk of HZ among individuals 50 years and older with and without laboratory confirmed SARS-CoV2 infection. Compare the risk of HZ among individuals 18 years and older with and without laboratory confirmed SARS-CoV2 infection. Compare the risk of HZ in overall population older than 18 years old in the pandemic period against pre-pandemic period. Describe the likelihood of developing HZ after laboratory-confirmation of SARS-CoV2 according to severity of disease.
• Data analysis plan:
  To develop the primary objective, we will compare the incidence of HZ among SARS-Cov-2 free and Sars-Cov-2 laboratory-confirmed subjects 50 years and older during the pandemic period. For this purpose, models using individual patient data or grouped will be implemented.The risk of HZ in subjects with Sars-cov-2 respect to subjects without Sars-Cov-2 will be estimated by a multivariate Poisson or negative binomial model according to applicability assumptions. Individual data will be grouped by SARS-Cov-2 free and Sars-Cov-2 laboratory-confirmed exposure, age, sex and comorbidities. Individual and grouped data can both be analyzed with the Poisson (or Negative binomial) distribution. Given the usual large size of the cohort, estimation when using grouped data is considerably quicker than when using individual level data and the results for both approaches are remarkably similar. The number of HZ cases by aggregation unit will be compared among SARS-Cov-2 free and lab-confirmed subjects.