Face masks and polycythemia is the standard hemoglobin cutoff valid in the pandemic?

BACKGROUND: Polycythemia is a common reason for patients' admissions. With the introduction of COVID-19, face masks reached very common usage in the population. Masks may cause some degree of hypoxia that may result in high hemoglobin in healthy individuals. Here, we aimed to investigate the frequency of patients applying for high hemoglobin and tested for possible polycythemia vera (PV) in the pandemic era. MATERIALS AND METHODS: We collected patients who applied to the hematology outpatient clinic between March 2019 and April 2021 for the study. The research was carried out at a single center at Ankara Oncology Training and Research Hospital. We collected demographic data such as age and sex, laboratory parameters such as complete blood count and erythropoietin level, concomitant diseases, smoking history, and spleen size. RESULTS: The median age of the cohort was 41 (16–83). Groups were different regarding age (P = 0.04). Groups were similar regarding gender (P = 0.350). Comorbidities were similar in both groups. Smoking was more frequent in the pre-COVID era group (P = 0.046). The frequency of the Janus kinase 2 (JAK2) test order was 102 examinations out of 7920 for the pre-COVID era and 152 examinations out of 6087 for the COVID era; this was statistically significant (P < 0.001). CONCLUSION: Clinicians may need to re-evaluate the threshold of hemoglobin levels to order JAK2 tests in the pandemic era, and the significance of mildly elevated hemoglobin may be neglected while testing for potential PV.