Seasonal variations in hematological disorders: A 10-year single-center experience

To assess the seasonal variations in hematological disorders among patients diagnosed on the basis of bone marrow biopsy, who attended National Institute of Blood Diseases (NIBD) clinics during 2006 to 2015.

We retrospectively reviewed the 10-year records of hematological disorders among patients' NIBD clinics from year 2006 to 2015. All cases of aplastic anemia (AA), acute lymphoblastic leukemia (ALL), acute myeloid leukemia (AML), immune thrombocytopenic purpura (ITP), and acute promyelocytic leukemia (APML) were categorized on the basis of the seasons in which they were diagnosed such as winter (December-February), spring (March-May), southwest monsoon periods (June-September), and retreating monsoon period (October and November). Statistical analysis was performed by using SPSS and STATA. Inferential statistics were explored using the chi-square test for heterogeneity to evaluate seasonal variations. P-value <0.05 was taken as significant.

A total of 1982 cases were reviewed. Men were predominantly higher (n = 1190, 60%) as compared to women (n = 792, 40%). Frequency of ALL was found to be higher (513, 25.9%), followed by ITP (504, 25.4%), AML (490, 24.7%), AA (396, 20%), while APML was observed in only 79 (4%) patients. Seasonal variations in the diagnosis of hematological disorders were observed (P-value < .001), except in APML diagnosis (P-value = .445). Significant seasonal variations were also detected in both genders in stratified analysis.

The finding of this study has reported an increase in the hematological disorder during 2006 to 2015. Particularly, majority of the cases were reported in southwest monsoon period, whereas least cases were reported in retreating period. Significant seasonal and yearly variations were detected in all diagnosis except the APML.