Table 2.
Association between pain (continuous [10-point increase] and dichotomous measures) and incident dementia: analysis using Cox regression.
| Total pain | Pain intensity | Pain interference | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| N cases/N total | Model 1* | Model 2† | N cases/N total | Model 1* | Model 2† | N cases/N Total | Model 1* | Model 2† | |||||||
| HR | 95% CI | HR | 95% CI | HR | 95% CI | HR | 95% CI | HR | 95% CI | HR | 95% CI | ||||
| Pain in 1991-1993 (mean follow-up = 25.0 y, SD = 4.7) | |||||||||||||||
| Pain score | 508/8281 | 1.05‡ | 1.01, 1.10 | 1.04 | 0.99, 1.09 | 508/8281 | 1.04‡ | 1.00, 1.08 | 1.03 | 0.99, 1.07 | 508/8281 | 1.05‡ | 1.00, 1.09 | 1.03 | 0.99, 1.08 |
| Moderate to severe pain | |||||||||||||||
| No | 427/7240 | 1 | Ref. | 1 | Ref. | 410/7057 | 1 | Ref. | 1 | Ref. | 454/7665 | 1 | Ref. | 1 | Ref. |
| Yes | 81/1041 | 1.20 | 0.94, 1.52 | 1.12 | 0.87, 1.44 | 98/1224 | 1.25 | 0.99, 1.57 | 1.19 | 0.95, 1.51 | 54/616 | 1.29 | 0.97, 1.72 | 1.21 | 0.90, 1.63 |
| Pain in 1997-1999 (mean follow-up = 19.6 y, SD = 3.8) | |||||||||||||||
| Pain score | 425/7026 | 1.07§ | 1.03, 1.12 | 1.05‡ | 1.00, 1.10 | 425/7026 | 1.06§ | 1.02, 1.10 | 1.04 | 0.99, 1.08 | 425/7026 | 1.07§ | 1.02, 1.11 | 1.04 | 0.99, 1.09 |
| Moderate to severe pain | |||||||||||||||
| No | 334/5879 | 1 | Ref. | 1 | Ref. | 327/5814 | 1 | Ref. | 1 | Ref. | 357/6300 | 1 | Ref. | 1 | Ref. |
| Yes | 91/1147 | 1.23 | 0.97, 1.57 | 1.10 | 0.85, 1.42 | 98/1212 | 1.29‡ | 1.02, 1.63 | 1.17 | 0.91, 1.50 | 68/726 | 1.44§ | 1.11, 1.88 | 1.27 | 0.96, 1.69 |
| Pain in 2002-2004 (mean follow-up = 14.5 y, SD = 2.9) | |||||||||||||||
| Pain score | 397/6752 | 1.04 | 0.99, 1.09 | 1.02 | 0.97, 1.07 | 397/6752 | 1.02 | 0.98, 1.07 | 1.00 | 0.96, 1.05 | 397/6752 | 1.05‡ | 1.01, 1.10 | 1.03 | 0.98, 1.08 |
| Moderate to severe pain | |||||||||||||||
| No | 291/5434 | 1 | Ref. | 1 | Ref. | 291/5317 | 1 | Ref. | 1 | Ref. | 324/5939 | 1 | Ref. | 1 | Ref. |
| Yes | 106/1318 | 1.33‡ | 1.05, 1.67 | 1.19 | 0.93, 1.54 | 106/1435 | 1.20 | 0.95, 1.51 | 1.06 | 0.83, 1.37 | 73/813 | 1.36‡ | 1.05, 1.77 | 1.21 | 0.90, 1.62 |
| Pain in 2007-2009 (mean follow-up = 10.0 y, SD = 2.0) | |||||||||||||||
| Pain score | 329/6588 | 1.06‡ | 1.01, 1.12 | 1.03 | 0.97, 1.09 | 329/6588 | 1.02 | 0.97, 1.07 | 0.99 | 0.93, 1.04 | 329/6588 | 1.08‖ | 1.03, 1.13 | 1.06‡ | 1.01, 1.11 |
| Moderate to severe pain | |||||||||||||||
| No | 233/5223 | 1 | Ref. | 1 | Ref. | 240/5157 | 1 | Ref. | 1 | Ref. | 258/5742 | 1 | Ref. | 1 | Ref. |
| Yes | 96/1365 | 1.26 | 0.98, 1.61 | 1.07 | 0.82, 1.41 | 89/1431 | 1.09 | 0.85, 1.40 | 0.90 | 0.68, 1.19 | 71/846 | 1.42‡ | 1.08, 1.87 | 1.21 | 0.90, 1.63 |
| Pain in 2012-2013 (Mean follow-up = 6.2 y, SD = 1.1) | |||||||||||||||
| Pain score | 233/6129 | 1.10§ | 1.04, 1.16 | 1.08‡ | 1.02, 1.16 | 233/6129 | 1.05 | 0.99, 1.11 | 1.03 | 0.97, 1.09 | 233/6129 | 1.12‖¦ | 1.06, 1.17 | 1.11‖¦ | 1.05, 1.18 |
| Moderate to severe pain | |||||||||||||||
| No | 140/4751 | 1 | Ref. | 1 | Ref. | 149/4720 | 1 | Ref. | 1 | Ref. | 162/5224 | 1 | Ref. | 1 | Ref. |
| Yes | 93/1378 | 1.78‖ | 1.36, 2.35 | 1.72‖ | 1.28, 2.33 | 84/1409 | 1.51§ | 1.14, 1.99 | 1.41‡ | 1.04, 1.92 | 71/905 | 1.88‖ | 1.40, 2.52 | 1.80‖ | 1.30, 2.49 |
| Pain in 2015-2016 (mean follow-up = 3.2 y, SD = 0.6) | |||||||||||||||
| Pain score | 100/5355 | 1.14§ | 1.05, 1.24 | 1.12‡ | 1.02, 1.24 | 100/5355 | 1.07 | 0.99, 1.17 | 1.05 | 0.96, 1.15 | 100/5355 | 1.15‖ | 1.07, 1.24 | 1.15‖ | 1.06, 1.25 |
| Moderate to severe pain | |||||||||||||||
| No | 55/4082 | 1 | Ref. | 1 | Ref. | 61/4041 | 1 | Ref. | 1 | Ref. | 63/4521 | 1 | Ref. | 1 | Ref. |
| Yes | 45/1273 | 2.23‖ | 1.48, 3.36 | 2.17‖ | 1.40, 3.38 | 39/1314 | 1.72‡ | 1.13, 2.61 | 1.59‡ | 1.01, 2.50 | 37/834 | 2.62‖ | 1.71, 4.01 | 2.57‖ | 1.61, 4.09 |
*
Model 1: adjusted for age (as timescale), sex, birth cohort, education, ethnicity, and marital status.
†
Model 2: model 1 + pain medication use, multimorbidity index, and depression assessed at the time of pain measurement.
‡
P < 0.05.
§
P < 0.01.
‖
P < 0.001.
CI, confidence intervals; HR, hazard ratio.