. 2020 Sep 21;3(9):e2013573. doi: 10.1001/jamanetworkopen.2020.13573

Table 3. Mean Difference in Rate of Change in Global Cognitive Decline (SD per Year) During Follow-up Using Linear Mixed Models.

Sleep duration per night, h	ELSA (n = 9254)		CHARLS (n = 10 811)		Pooled analysis (N = 20 065)
Sleep duration per night, h	β (95% Cl)^a	P value	β (95% Cl)^a	P value	Pooled β (95% Cl)	P value^b	I² statistic, %	P value^c
≤4	−0.021 (−0.038 to −0.003)	.02	−0.024 (−0.044 to −0.003)	.02	−0.022 (−0.035 to −0.009)	.001	0	.83
5	−0.004 (−0.018 to 0.009)	.51	−0.007 (−0.028 to 0.014)	.51	−0.005 (−0.017 to 0.006)	.37	0	.84
6	−0.005 (−0.015 to 0.005)	.33	−0.003 (−0.022 to 0.015)	.71	−0.005 (−0.013 to 0.004)	.30	0	.89
7	1 [Reference]	NA	1 [Reference]	NA	1 [Reference]	NA	NA	NA
8	−0.004 (−0.012 to 0.005)	.45	−0.001 (−0.020 to 0.017)	.88	−0.003 (−0.011 to 0.005)	.45	0	.85
9	−0.023 (−0.041 to −0.006)	.007	0.009 (−0.025 to 0.042)	.61	−0.011 (−0.042 to 0.020)	.49	64.4	.09
≥10	−0.030 (−0.059 to −0.001)	.05	−0.036 (−0.068 to −0.004)	.03	−0.033 (−0.054 to −0.011)	.003	0	.78

Abbreviations: CHARLS, China Health and Retirement Longitudinal Study; ELSA, English Longitudinal Study of Ageing; NA, not applicable.

^{^a}

After adjusting for sex, age, body mass index, systolic blood pressure, level of education, Center for Epidemiologic Studies Depression Scale score, cohabitation status, current smoking, alcohol consumption, diabetes, coronary heart disease, stroke, cancer, chronic lung disease, and asthma.

^{^b}

For the pooled β.

^{^c}

For the I² statistic.