Table 3 Association between sleep quality score, sleep duration and the frailty index

Sleep quality category

0–4

Reference

Reference

Reference

Reference

5–9

1.40 (1.32, 1.49)**

1.26 (1.18, 1.34)**

1.26 (1.19, 1.34)**

1.27 (1.20, 1.35)**

10–14

1.80 (1.65, 1.96)**

1.37 (1.25, 1.49)**

1.37 (1.25, 1.49)**

1.38 (1.26, 1.51)**

15–20

2.47 (2.17, 2.81)**

1.57 (1.38, 1.78)**

1.52 (1.33, 1.73)**

1.53 (1.34, 1.75)**

Sleep duration

 ≥ 6 & < 9 h

Reference

Reference

Reference

Reference

 < 6 h

1.43 (1.30, 1.58)**

1.16 (1.06, 1.28)**

1.14 (1.04, 1.25)*

1.01 (0.92, 1.11)

 ≥ 9 h

1.13 (1.01, 1.27)*

1.11 (1.00, 1.23)*

1.12 (1.01, 1.24)*

1.18 (1.07, 1.31)*