Month of Diagnosis
Monthly heterogeneity for all 394 cases was statistically significant using the chi-square test (P < 0.038)(Table 2), which indicated a non-uniform distribution of cases; in stratified analyses no such effect was found among males (P = 0.514), females (P = 0.952), children (P = 0.163) and adolescents (P = 0.304).
The Poisson regression modelling indicated that the month in which an annual peak was observed was March (10.7% of all cases(Figure 2). The month with the lowest number of cases was September (5.8% of all cases). Considering patients of all ages, 13.6% of the male cases were diagnosed in July, while only 5.7% of females were diagnosed in this month.