3.5  Absolute lymphocyte count and neutrophil-to-lymphocyte ratio
Compared to patients in the good-sleep group, patients in the poor-sleep group had significantly decreased ALC on day 14 (median, 1.10 [IQR, 0.88–1.35] vs 1.32 [IQR, 1.04–1.59], P = 0.0055) and day 21 after hospital admission (median, 1.18 [IQR, 0.92–1.45] vs 1.48 [IQR, 1.10–1.98], P = 0.0034). Patients in the poor-sleep group also had an increased NLR on day 14 (median, 3.17 [IQR, 2.27–4.66] vs 2.44 [IQR, 2.05–3.75], P = 0.0284) and day 21 (median, 2.73 [IQR, 2.10–5.90] vs 2.23 [IQR, 1.63–2.92], P = 0.0092) than those in the good-sleep group (Fig. 2 ). The recovery rate based on ALC was higher in patients in the good-sleep group on day 14 (median, 56.91 [IQR, 8.67–94.54] vs 69.40 [IQR, 43.67–132.40], P = 0.0255) and day 21 (median, 61.40 [IQR, 26.81–102.82] vs 111.47 [IQR, 65.38–183.05], P = 0.0003) than those in the poor-sleep group; similar results were found regarding the deterioration based on an increased NLR on day 7 (median, −15.01 [IQR, −43.02–0.82] vs −39.24 [IQR, −60.34–-0.24], P = 0.0314), day 14 (median, −39.65 [IQR, −62.06–-12.94] vs −61.09 [IQR, −70.87––23.50], P = 0.0155), and day 21 (median, −51.40% [IQR, −61.08––22.36] vs −75.43 [IQR, −82.19–-47.77], P = 0.0003) (Fig. 2).
Fig. 2 Effects of self-reported sleep quality on recovery from lymphopenia. Dynamic changes in absolute lymphocyte count (ALC; A) and neutrophil-to-lymphocyte ratio (NLR; B) within 24 h (baseline value), on day 7, 14, and 21 after hospital admission in patients with COVID-19 in the good-sleep and poor-sleep groups. Dynamic changes in the ALC recovery rate (C) and NLR deterioration rate (D) on day 7, 14, and 21 after hospital admission in patients with COVID-19 in the good-sleep and poor-sleep groups. Data were missing in five patients (8.3%) on day 7, and three patients (5.0%) on day 21 in the good-sleep group. Data were missing in five patients (6.6%) on day 7, three patients (4.0%) on day 14, and four patients (5.3%) on day 21 in the poor-sleep group. ***P < 0.001 and ****P < 0.0001 when compared to the baseline value of the good-sleep group; §§P < 0.01 and §§§§P < 0.0001 when compared to baseline values of the poor-sleep group; ##P < 0.01 and ###P < 0.001 when compared to values on day 7 in the good-sleep group; &&P < 0.01 and &&&P < 0.001 when compared to values on day 7 in the poor-sleep group; N.S., not significant. P < 0.05 was considered statistically significant.