Abstract
BackgroundHerpes zoster (HZ) may result in severe complications requiring hospital treatment, particularly in patients with comorbidity. Nevertheless, data on HZ from nationwide population-based hospital registries are sparse.MethodsWe conducted a cohort study describing first-time hospital-based (inpatient, outpatient, and emergency room) HZ diagnoses in the Danish National Patient Registry, 1994–2012. We computed the diagnosis rate; prevalence of demographic characteristics, comorbidities, and complications; length of hospital stay; and standardized mortality ratios (SMRs) using the Danish population as reference. We classified comorbidity using the Charlson Comorbidity Index (CCI) scoring system and categorized patients in groups of no (score 0), moderate (score 1), severe (score 2), and very severe comorbidity (score ≥3). In addition, we computed the prevalence of certain conditions associated with immune dysregulation (stem cell or bone marrow transplantation, solid organ transplantation, HIV infection, primary immunodeficiency, any cancer, and autoimmune diseases).ResultsThe diagnosis rate increased almost exponentially from 6 to 91.9 per 100,000 person-years between age 50 and ≥90 years. The age-standardized rate was stable throughout the study period. The median length of hospital stay was 4 days (interquartile range: 1–8 days) for inpatients with HZ as the main reason for admission. According to the CCI, 44.3 % of patients had no comorbidity, 17.3 % moderate comorbidity, 17.4 % severe comorbidity, and 21.0 % very severe comorbidity. Comorbidities involving immune dysregulation, such as malignant (21 %) and autoimmune diseases (17 %), were particularly prevalent. Thirty percent had neurological, ophthalmic, or other complications. HZ was associated with increased all-cause mortality overall (SMR 1.8, 95 % CI: 1.7–1.8), but not in analyses restricted to patients without comorbidity (SMR 1.0, 95 % CI: 0.9–1.0).ConclusionsThis study provides estimates of the epidemiology of hospital-based (severe) HZ. The diagnosis rate increased substantially with age. Complications and comorbidities were prevalent, likely resulting in increased mortality.Electronic supplementary materialThe online version of this article (doi:10.1186/s12879-016-1369-6) contains supplementary material, which is available to authorized users.
Highlights
Herpes zoster (HZ) may result in severe complications requiring hospital treatment, in patients with comorbidity
Hospital diagnosis rate We identified 13,663 first-time hospital-based diagnoses of HZ in Denmark between 1994 and 2012, corresponding to a standardized HZ rate of 13.1 per 100,000 person-years (Table 1)
The increase in rate with age was observed for all subtypes of HZ diagnoses, but was most pronounced for inpatient diagnoses (Fig. 2)
Summary
Herpes zoster (HZ) may result in severe complications requiring hospital treatment, in patients with comorbidity. Schmidt et al BMC Infectious Diseases (2016) 16:99 predisposing conditions [3, 4] These patients are more likely to be treated in the hospital or in hospital outpatient specialty clinics. Results from nationwide population-based hospital registries in Europe are sparse concerning the diagnosis rate and patient characteristics, including prevalence of complications and comorbidities. None of the previous population-based studies published data pertaining to diagnoses from hospital outpatient specialty clinics. To address this paucity of data, we conducted a nationwide Danish cohort study describing HZ in a hospital-based setting, including diagnosis rate, patient demographics, severity, comorbidity burden, length of admission, and subsequent all-cause mortality
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
