Table 4.

Prevalence, 95% Confidence Intervals (CI) and I² Statistic Overall and for Several Sensitivity Analyses

	No. Prevalence Estimates	Prevalence (%)	95% CI	I2 (P Value)
Overall	84	39	34–44	100% (P < 0.00001)
Sensitivity analyses
Age <60 y	56	37	31–44	100% (P < 0.00001)
Age ≥60 y	28	44	36–55
Year of analysis <2010	31 53	35 42	31–40 32–54	100% (P < 0.00001)
Year of analysis ≥2010
PSQI	48	46	35–62	100% (P < 0.00001)
Other than PSQI	36	31	27–36
Strong quality	34	39	33–47	100% (P < 0.00001)
Moderate quality	46	39	32–48	100% (P < 0.00001)
Weak quality	4	44	29–68	99% (P < 0.00001)
With comorbidities	9	60	46–79	99% (P < 0.00001)
No comorbidities	74	37	33–43	100% (P < 0.00001)
N < 100	22	40	25–64	100% (P < 0.00001)
N = 100–199	21	55	46–67	99% (P < 0.00001)
N = 200–299	14	46	38–55	99% (P < 0.00001)
N = 300–999	18	32	22–47	100% (P < 0.00001)
N > 1000	9	24	17–34	100% (P < 0.00001)
Studies with no comorbidities, with PSQI, of strong quality and with sample size >200	17	39	30–51	100% (P < 0.00001)

Abbreviation: PSQI = Pittsburgh Sleep Quality Index.