Table 5

Incident functional limitations predicted by Restless Legs Syndrome* at baseline (2002, N = 1008) in the Health and Retirement Study (Follow-up until 2008)
Functional Limitation Outcome Unadjusted Multivariate Adjusted
At Risk Disability HR 95% CI p HR 95% CI p
Mobility limitations 524 247 2.26 (1.21, 4.23) 0.01 1.90 (0.97, 3.70) 0.06
Difficulty climbing several flights 564 246 3.13 (2.03, 4.85) <0.001 2.38 (1.39, 4.06) 0.002
Difficulty climbing one flight 780 180 3.62 (2.36, 5.55) <0.001 1.51 (0.96, 2.40) 0.08
Large muscle group limitations 371 210 1.97 (0.86, 4.53) 0.11 1.01 (0.48, 2.12) 0.98
Some difficulty sitting for 2 hours 745 178 3.26 (2.12, 5.01) <0.001 2.17 (1.25, 3.75) 0.006
Some difficulty rising from chair 565 224 3.16 (2.11, 4.73) <0.001 2.54 (1.62, 3.99) <0.001
Difficulty with stooping 518 245 4.09 (2.86, 5.86) <0.001 2.66 (1.71, 4.15) <0.001
Pushing or pulling a large object 721 238 3.23 (2.01, 5.19) <0.001 1.79 (1.08, 2.99) 0.02
Gross motor limitations† (At least 1) 731 212 2.43 (1.46, 4.03) 0.001 0.91 (0.52, 1.59) 0.73
Fine motor limitations‡ (At least 1) 826 154 2.45 (1.50, 4.01) <0.001 1.18 (0.72, 1.94) 0.52
Difficulty with lifting or carrying 10 lb 744 206 3.02 (1.99, 4.59) <0.001 1.61 (1.05, 2.46) 0.03
Difficulty picking up a dime 872 89 2.97 (1.69, 5.21) <0.001 1.97 (1.12, 3.46) 0.02
Difficulty reaching or extending arms up 799 173 3.22 (2.06, 5.06) <0.001 1.76 (1.05, 2.97) 0.03
ADL limitations (At least 1) 807 162 1.94 (1.11, 3.40) 0.02 0.64 (0.36, 1.13) 0.12
IADL limitations (At least 1) 843 139 2.62 (1.50, 4.57) 0.001 1.05 (0.60, 1.82) 0.87

* Restless Legs symptoms defined as unpleasant or restless sensations in the legs at least once per week, and reporting “restless, fidgety, or unable to sit still” feelings at rest and the need to “move, rub, or stretch legs” (n = 104 in 2002).

† Unadjusted hazard ratio shows incident disability. Functional limitation was assessed biannually, subjects censored if no longer eligible at follow-up waves. Multivariate-adjusted hazard ratio includes variables adjusted for in Table 3 (cross-sectionally associated with RLS, including: age, gender, income category (quartiles), health interfering with ability to work, pain symptoms (mild-moderate or severe compared to none), other sleep symptoms (walking too easily or too early), body mass index, current drinking status, number of chronic medications used, out-of-pocket medical expenses (quartiles), number of doctor visits in the last 2 y, and falls in the previous 2 y), as well as time-varying covariates associated with RLS in the follow-up waves (incident stroke, incident psychiatric diagnosis).

† Gross motor limitations defined as at least some difficulty in one of these domains: Walking 1 block, walking with an assistive device, climbing 1 flight of stairs, transferring, or bathing.

‡ Fine motor limitations defined as at least some difficulty in one of these domains: Picking up a dime, feeding oneself, or dressing oneself.

Abbreviations: HR = hazard ratio; CI = confidence interval; ADL = Activities of Daily Living; IADL = Instrumental Activities of Daily Living; y = years; lb = pounds.

Cirillo and Wallace

Cirillo and Wallace BMC Geriatrics 2012 12:39   doi:10.1186/1471-2318-12-39

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