Table 2.
Variables a | Case [N = 406] (Yes/No) | Control [N = 670] (Yes/No) | Crude OR [95% CI] | Adjusted OR [95% CI] (406 cases, 666 controls) |
---|---|---|---|---|
Age (in years) | -- | -- | 0.99 [0.97, 1.00] | 1.0 [0.98, 1.02] |
Gender (female = 1; male = 0) | 260/146 | 440/230 | 0.93 [0.72, 1.20] | 1.05 [0.80, 1.38] |
AECOPD | 66/340 | 81/589 | 1.41 [0.99, 2.01] | 1.47 [1.01, 2.13] c |
Pneumonia | 81/325 | 126/544 | 1.08 [0.79, 1.47] | 1.29 [0.92, 1.80] |
Acute CHF | 52/354 | 81/589 | 1.07 [0.74, 1.55] | 1.22 [0.82, 1.81] |
Current smoking | 53/353 | 70/596 | 1.28 [0.87, 1.87] | 1.08 [0.72, 1.62] |
History of cognitive impairment | 51/355 | 114/556 | 0.70 [0.49, 1.00] | 0.82 [0.56, 1.21] |
Medication uses | ||||
Muscle relaxants | 17/389 | 11/659 | 2.62 [1.21, 5.65] | 2.94 [1.29, 6.69]c |
Anti-cholinergic drugsb | 88/318 | 180/490 | 0.75 [0.56, 1.01] | 0.78 [0.58, 1.07] |
Potassium supplement | 74/332 | 189/481 | 0.57 [0.42, 0.77] | 0.64 [0.46, 0.89]c |
Calcium supplement | 64/342 | 143/527 | 0.69 [0.50, 0.95] | 0.76 [0.54, 1.07] |
Iron supplement | 26/380 | 79/591 | 0.51 [0.32, 0.81] | 0.57 [0.35, 0.92]c |
Diuretics | 178/228 | 336/334 | 0.78 [0.61, 0.99] | 0.87 [0.67, 1.14] |
Narcotics | 106/300 | 175/495 | 1.00 [0.75, 1.32] | 1.07 [0.79, 1.44] |
Antibiotics | 32/374 | 102/568 | 0.48 [0.31, 0.72] | 0.45 [0.29, 0.69]c |
aVariables were dichotomized as 1 = yes, 0 = no (baseline) unless stated otherwise. The adjusted OR with a 95% CI for the association between a risk factor and the presence of lower DF was estimated after adjusting for all other variables listed in this Table.
bAnticholinergic drugs include antipsychotics, H1 antihistamines, anti-muscarinic receptor blocker, and antispasmodic drugs.
cSignificant (p < 0.05).
Regression diagnostics showed no collinearity among risk factors, no noticeable outlier, no influential or ill-fitted observations, and the model fit data very well (Chi-square =6.77, df = 8, p = 0.56, Hosmer and Lemeshow goodness-of-fit test).
Abbreviations: AECOPD acute exacerbation of chronic obstructive pulmonary disease, CHF congestive heart failure, CI confidence interval, OR odds ratio.