Table 1

Characteristics of study subjects

Cases
N=4559
Controls
N=22 795
p Value
Age at index date, years74 (9)73 (10)N/A*
Female sex, %71%71%N/A*
Duration of follow-up before index date, years6.4 (4.6)6.5 (4.5)0.35
Charlson Comorbidity Index1 (0, 2)0 (0, 2)<0.01
Alcohol use, %67%66%0.27
Tobacco use, %51%43%<0.01
Prior use of glucocorticoid, %28%16%<0.01
No. of prescriptions†, median (IQR)3 (1, 10)3 (1, 9)<0.01
Time since last prescription (years)†, median (IQR)1.4 (0.6, 4.2)2.2 (0.8, 5.2)<0.01
Prior use of immunosuppressive therapy, %3%2%<0.01
No. of prescriptions†, median (IQR)19 (7, 51)22 (6, 56)0.98
Time since last prescription (years)†, median (IQR)0.8 (0.6, 3.7)0.7 (0.5, 4.7)0.14
Prior zoster vaccination, %0.6%0.4%0.09
Time since last vaccination (months)†, median (IQR)4 (2, 9)5 (2, 9)0.78
  • Data expressed as mean (SD) or percentage.

  • *Controls were age-matched and sex-matched to cases.

  • †Among patients who received a prescription.