Background
Methods
Participants and setting
Construction of the FI at baseline
Outcomes
Statistical analyses
Results
Characteristics of participants at baseline
Characteristics | Overall participants (n = 3,985) | Women without falls (n = 2471) | Women with one fall (n = 853) | Women with ≥2 falls (n = 630) | P-value |
---|---|---|---|---|---|
Age: mean (SDa), years | 69.4 (8.89) | 69.4 (8.58) | 69.6 (9.14) | 69.4 (9.74) | 0.748c
|
Age strata, n (%) | |||||
55-64 | 1,385 (34.76) | 839 (33.95) | 292 (34.23) | 248 (39.37) | 0.404d
|
65-74 | 1,423 (35.71) | 939 (38.00) | 285 (33.41) | 187 (29.68) | |
75-84 | 952 (23.89) | 578 (23.39) | 219 (25.67) | 142 (22.54) | |
≥85 | 225 (5.65) | 115 (4.65) | 57 (6.68) | 53 (8.41) | |
BMIb: mean (SD), kg/m2
| 27.7 (5.77) | 27.5 (5.54) | 27.7 (5.90) | 28.5 (6.40) | 0.002c
|
Smoker, n (%) | |||||
Yes | 447 (11.3) | 269 (10.96) | 97 (11.44) | 77 (12.32) | 0.623e
|
No | 3,510 (88.70) | 2185 (89.04) | 751 (88.56) | 548 (87.68) | |
Drinking (drinks/week), n (%) | |||||
0 | 2,027 (51.21) | 1239 (50.49) | 411 (48.52) | 360 (57.51) | 0.057d
|
<7 | 1,414 (35.73) | 886 (36.10) | 324 (38.25) | 193 (30.83) | |
7-13 | 428 (10.81) | 276 (11.25) | 94 (11.10) | 56 (8.95) | |
≥14 | 89 (2.25) | 53 (2.16) | 18 (2.13) | 17 (2.72) | |
Race, n (%) | |||||
White | 3,717 (93.27) | 2299 (93.04) | 798 (93.55) | 597 (94.76) | 0.293e
|
Non-white | 268 (6.73) | 172 (6.96) | 55 (6.45) | 33 (5.24) | |
Education, n (%) | |||||
High school or less | 2,509 (64.10) | 1608 (66.23) | 518 (61.74) | 360 (58.16) | <0.001e
|
More than high school | 1,405 (35.90) | 820 (33.77) | 321 (38.26) | 259 (41.84) | |
Family history of fractures, n (%) | |||||
Yes | 898 (23.81) | 514 (21.82) | 204 (25.40) | 172 (29.30) | <0.001e
|
No | 2,874 (76.19) | 1842 (78.18) | 599 (74.60) | 415 (70.70) | |
Overnight hospitalization in last 12 months, n (%) | |||||
0 | 3,498 (88.65) | 2213 (90.25) | 747 (88.30) | 516 (82.96) | <0.001d
|
1 | 337 (8.54) | 187 (7.63) | 78 (9.22) | 69 (11.09) | |
≥2 | 111 (2.81) | 52 (2.12) | 21 (2.48) | 37 (5.95) | |
Prior fractures since 45 years old, n (%) | |||||
Yes | 862 (22.31) | 447 (18.65) | 217 (26.08) | 193 (31.64) | <0.001e
|
No | 3,001 (77.69) | 1950 (81.35) | 615 (73.92) | 417 (68.36) | |
Frailty index: mean (SD) | 0.24 (0.13) | 0.22 (0.12) | 0.25 (0.13) | 0.31 (0.15) | <0.001c
|
FI and its relation to age
Variables | Coding | Falls | |
---|---|---|---|
OR (95% CI, P-value)a
| n (%)b
| ||
Co-morbidities (n = 15)
| |||
Taking/taken five or more medicationsc
| Yes = 1, no = 0 | 1.30 (1.07-1.59) 0.008 | 607 (15.23) |
Has chronic bronchitis or emphysemac
| Yes = 1, no = 0 | 1.40 (1.08-1.81) 0.012 | 307 (7.93) |
Has osteoarthritis or degenerative joint diseasec
| Yes = 1, no = 0 | 1.53 (1.32-1.78) <0.001 | 1,354 (35.05) |
Has rheumatoid arthritisc
| Yes = 1, no = 0 | 1.45 (1.16-1.81) <0.001 | 447 (11.57) |
Suffers from strokec
| Yes = 1, no = 0 | 2.16 (1.55-3.00) <0.001 | 193 (4.92) |
Has ulcerative colitis or Crohn’s diseasec
| Yes = 1, no = 0 | 2.08 (1.32-3.28) 0.002 | 82 (2.09) |
Has celiac diseasec
| Yes = 1, no = 0 | 1.20 (0.50-2.88) 0.683 | 25 (0.64) |
Has Parkinson’s diseasec
| Yes = 1, no = 0 | 3.09 (0.98-9.74) 0.054 | 18 (0.46) |
Has multiple sclerosisc
| Yes = 1, no = 0 | 1.28 (0.52-3.17) 0.596 | 22 (0.56) |
Has cancerc
| Yes = 1, no = 0 | 1.06 (0.86-1.32) 0.570 | 502 (12.77) |
Has diabetes (type-1)c
| Yes = 1, no = 0 | 1.44 (1.00-2.08) 0.053 | 165 (4.22) |
Has hypertensionc
| Yes = 1, no = 0 | 1.14 (0.99-1.32) 0.077 | 2,025 (51.63) |
Has heart diseasec
| Yes = 1, no = 0 | 1.52 (1.25-1.86) <0.001 | 623 (16.01) |
Has high cholesterolc
| Yes = 1, no = 0 | 1.15 (1.00-1.33) 0.050 | 1,752 (45.03) |
Self rating of healthd
| Excellent = 0, very good = 0.25, good = 0.5, fair = 0.75, poor = 1 | 2.77 (1.99-3.86) <0.001 | 73 (1.85) |
Activities of daily living (ADL) (n = 12)
| |||
Limitations in vigorous activitiesc
| Yes = 1, a little = 0.5, no = 0 | 1.67 (1.37-2.05) <0.001 | 1,735 (45.49) |
Limitations in moderate activitiesd
| Yes = 1, a little = 0.5, no = 0 | 2.04 (1.65-2.52) <0.001 | 569 (14.59) |
Limitations in lifting or carrying groceriesd
| Yes = 1, a little = 0.5, no = 0 | 2.01 (1.61-2.52) <0.001 | 416 (10.62) |
Limitations in climbing one flight of stairsd
| Yes = 1, a little = 0.5, no = 0 | 2.22 (1.76-2.80) <0.001 | 374 (9.69) |
Limitations bending, kneeling or stoopingd
| Yes = 1, a little = 0.5, no = 0 | 2.02 (1.66-2.46) <0.001 | 781 (20.12) |
Limitations walking one hundred yardsd
| Yes = 1, a little = 0.5, no = 0 | 1.97 (1.56-2.48) <0.001 | 378 (9.88) |
Limitations in bathing or dressing yourselfd
| Yes = 1, a little = 0.5, no = 0 | 1.88 (1.37-2.59) <0.001 | 154 (3.93) |
Needs arms to help stand up from a chaird
| Yes = 1, no = 0 | 1.83 (1.57-2.13) <0.001 | 1,495 (37.98) |
Number of days to walk at least 20 minutes in the past 30 daysd
| ≤2 days = 1, >2 days = 0 | 1.21 (1.02-1.43) 0.025 | 1,081 (27.50) |
Self rating of mobilityd
| Unable = 1, some problem = 0.5, no problem = 0 | 3.05 (2.22-4.18) <0.001 | 1 (0.03) |
Self rating of self-cared
| Unable = 1, some problem = 0.5, no problem = 0 | 6.83 (3.75-12.43) <0.001 | 4 (0.10) |
Self rating of usual activitiesd
| Unable = 1, some problem = 0.5, no problem = 0 | 3.60 (2.68-4.84) <0.001 | 56 (1.41) |
Symptoms and sig
ns (n = 6)
| |||
Feels full of lifed
| All the time = 0, most of time = 0.25, some time = 0.5, a little time = 0.75, none of time = 1 | 3.61 (2.66-4.89) <0.001 | 228 (5.84) |
Has a lot of energyd
| All the time = 0, most of time = 0.25, some time = 0.5, a little time = 0.75, none of time = 1 | 3.91 (2.88-5.31) <0.001 | 263 (6.73) |
Feels worn outd
| All the time = 1, most of time = 0.75, some time = 0.5, a little time = 0.25, none of time = 0 | 3.73 (2.73-5.09) <0.001 | 123 (3.15) |
Feels tiredd
| All the time = 1, most of time = 0.75, some time = 0.5, a little time = 0.25, none of time = 0 | 4.14 (2.98-5.76) <0.001 | 173 (4.40) |
Self rating of pain/discomfortd
| Extremely = 1, moderate = 0.5, no = 0 | 3.22 (2.43-4.28) <0.001 | 242 (6.15) |
Unintentional weight loss of 10 poundsc
| Yes = 1, no = 0 | 1.42 (1.12-1.80) 0.004 | 433 (11.01) |
Healthcare utilization
(n = 1)
| |||
Times of visiting a healthcare provider to get medical care in the past yearc
| None = 0, 1–2 times = 0.33, 3–5 times = 0.67, 6 or more times = 1 | 1.39 (1.28-1.51) <0.001 | 842 (21.43) |
Relationship between the FI and falls
Outcomes | n (%) | Age-adjusted models | Fully-adjusted models | ||
---|---|---|---|---|---|
Statistics (95% CI)a
| P-value | Statistics (95% CI)a
| P-value | ||
Falls
b
| 1,068 (31.89) | 1.03 (1.03-1.04) | <0.001 | 1.02 (1.02-1.03) | <0.001 |
Women < 65 years | 395 (31.98) | 1.03 (1.02-1.04) | <0.001 | 1.02 (1.01-1.03) | 0.001 |
Women ≥ 65 years | 673 (31.84) | 1.03 (1.02-1.04) | <0.001 | 1.03 (1.02-1.04) | <0.001 |
Fractures
c
| |||||
All fractures
d
| 238 (6.36) | 1.02 (1.01-1.03) | <0.001 | 1.02 (1.01-1.03) | <0.001 |
Women < 65 years | 71 (5.35) | 1.02 (1.002-1.04) | 0.032 | 1.02 (1.00-1.04) | 0.019 |
Women ≥ 65 years | 167 (6.92) | 1.02 (1.01-1.03) | 0.002 | 1.02 (1.01-1.03) | 0.002 |
Hip fracture
| 18 (0.51)g
| 1.04 (1.00-1.07) | 0.041 | 1.04 (1.00-1.07) | 0.051 |
Women < 65 years | 4 (0.30) | —k
| —k
| —k
| —k
|
Women ≥ 65 years | 14 (0.58) | 1.03 (0.99-1.07) | 0.201 | 1.02 (0.99-1.07) | 0.230 |
Spine fracture
| 28 (0.79)h
| 1.04 (1.01-1.07) | 0.004 | 1.03 (1.00-1.06) | 0.024 |
Women < 65 years | 6 (0.45) | —k
| —k
| —k
| —k
|
Women ≥ 65 years | 22 (0.91) | 1.04 (1.01-1.07) | 0.009 | 1.03 (1.00-1.06) | 0.083 |
Other fractures
| 208 (5.56)i
| 1.02 (1.01-1.03) | <0.001 | 1.02 (1.01-1.03) | <0.001 |
Women < 65 years | 65 (4.90) | 1.02 (1.00-1.04) | 0.021 | 1.02 (1.00-1.05) | 0.027 |
Women ≥ 65 years | 143 (5.92) | 1.02 (1.00-1.03) | 0.008 | 1.02 (1.00-1.03) | 0.015 |
Death
e
| 107 (2.69) | 1.04 (1.03-1.06) | <0.001 | 1.05 (1.03-1.06) | <0.001 |
Women < 65 years | 12 (0.87) | 1.04 (0.99-1.08) | 0.093 | 1.05 (1.01-1.10) | 0.028 |
Women ≥ 65 years | 95 (3.65) | 1.05 (1.03-1.06) | <0.001 | 1.05 (1.03-1.06) | <0.001 |
Overnight hospitalizations
f
| 347 (8.75)j
| 1.03 (1.02-1.04) | <0.001 | 1.02 (1.02-1.03) | <0.001 |
Women < 65 years | 75 (5.43)j
| 1.07 (1.06-1.08) | <0.001 | 1.05 (1.04-1.06) | <0.001 |
Women ≥ 65 years | 272 (10.52)j
| 1.02 (1.01-1.03) | <0.001 | 1.02 (1.01-1.02) | <0.001 |
Sensitivity analysis | n (%) | Age-adjusted models | Fully-adjusted models | ||||
---|---|---|---|---|---|---|---|
OR (95% CI)a
| P-value | AUCb
| OR (95% CI) | P-value | AUC | ||
Any falls at baseline and during the 3-year follow-up
c
| |||||||
Baseline falls
| 1483 (37.51) | 1.03 (1.03-1.04) | <0.001 | 0.61 | 1.04 (1.03-1.04) | <0.001 | 0.62 |
Women < 65 years | 540 (39.16) | 1.04 (1.03-1.05) | <0.001 | 0.64 | 1.04 (1.03-1.05) | <0.001 | 0.64 |
Women ≥ 65 years | 943 (36.62) | 1.03 (1.02-1.04) | <0.001 | 0.61 | 1.03 (1.03-1.04) | <0.001 | 0.62 |
New incident falls
d
| 1204 (51.43) | 1.02 (1.02-1.03) | <0.001 | 0.59 | 1.02 (1.02-1.03) | <0.001 | 0.60 |
Women < 65 years | 384 (47.64) | 1.02 (1.00-1.03) | 0.015 | 0.56 | 1.02 (1.00-1.03) | 0.018 | 0.58 |
Women ≥ 65 years | 820 (53.42) | 1.02 (1.02-1.03) | <0.001 | 0.61 | 1.03 (1.02-1.04) | <0.001 | 0.61 |
Recurrence of falls
e
| 1135 (81.54) | 1.04 (1.03-1.05) | <0.001 | 0.64 | 1.04 (1.03-1.06) | <0.001 | 0.64 |
Women < 65 years | 419 (80.58) | 1.05 (1.03-1.07) | <0.001 | 0.66 | 1.06 (1.03-1.08) | <0.001 | 0.68 |
Women ≥ 65 years | 716 (82.11) | 1.04 (1.02-1.05) | <0.001 | 0.63 | 1.04 (1.02-1.05) | <0.001 | 0.66 |
Analysis with multiple imputation for missing data
f
| 1317 (33.05)g
| 1.03 (1.03-1.04) | <0.001 | 0.61 | 1.02 (1.02-1.03) | <0.001 | 0.69 |
Women < 65 years | 448 (32.35)g
| 1.03 (1.02-1.04) | <0.001 | 0.60 | 1.02 (1.01-1.03) | 0.004 | 0.72 |
Women ≥ 65 years | 869 (33.42)g
| 1.03 (1.03-1.04) | <0.001 | 0.62 | 1.02 (1.02-1.03) | <0.001 | 0.68 |