Table 2.
Analysis of risk factors by significance in bivariate models. Studies by Sieber et al (Sieber et al., 2011) and Zakriya et al. (Zakriya et al., 2002) from Table 1 were not included in Table 2 because they are subgroup analysis from the same study cohort as the study by Lee et al. (Lee et al., 2011). Lee et al. was chosen for this analysis as the study includes the largest number of subjects from the same cohort. P-values are not stated if they were not reported or could not be calculated from other data available.
| Risk Factors (p-value) |
Cognitive Impair- ment |
Age | Gender | Institu- tionalization |
Functional Impairment a |
BMI and Albuminb |
Multiple Co- morbidities |
ASA c Classi- fication |
Acute Medical Condi- tions d |
Poly- pharmacy e |
Vision Impair- ment |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Study | |||||||||||
| Andersson (2001) | S (<0.0001) | S (<0.0001) | S (<0.002) | S (<0.02) | S (<0.01) | S (<0.0001) | |||||
|
| |||||||||||
| Bjoro (2008) | S (0.000) | S (0.009) | S (0.002) | S (0.004) |
S
f (0.003) NS (0.26) |
NS (0.67) | S (0.009) | NS (0.19) | |||
|
| |||||||||||
| Goldenberg (2006)g | S | S | S | S | S | S | S | ||||
|
| |||||||||||
| Juliebo (2009) | S (<0.001) | S (0.005) | NS (0.41) | S (0.005) | S (0.001) |
S
h (0.003) NS (0.64) |
NS (0.56) | S (0.004) | S (0.002) | ||
|
| |||||||||||
| Lee (2011)i | S (0.000) | S (0.002) | S (0.004) | NS (0.84) | S (0.000) | S (0.000) | |||||
|
| |||||||||||
| Morrison (2003)j | S (<0.001) | S (0.02) | S (0.11) | S (0.08) | S (0.001) | S k | |||||
|
| |||||||||||
| Nie (2011) | NS l (0.61) | NS (0.54) | NS (0.39) | ||||||||
|
| |||||||||||
| Santos (2005) | S (0.03) | NS (0.62) | NS (0.36) | S (0.013) | NS (0.34) | ||||||
Functional impairment was defined differently in studies: “help from others before admission”(Andersson, Gustafson, Hallberg, 2001), ADL score ≥ 2 (GOLDENBERG et al., 2006), Barthel index 19 or 20 (Juliebo et al., 2009), and FIM score (Morrison et al., 2003).
BMI in quartiles (Lee et al., 2011), BMI ≤ 20kg/m2(Bjoro, 2008; Juliebo et al., 2009), albumin <3.4g/dL (Bjoro, 2008), albumin (median value) (Juliebo et al., 2009), or albumin < 3.5 g/dL (GOLDENBERG et al., 2006).
American Society of Anesthesiologist (ASA). ASA group III, IV, or V (Juliebo et al., 2009), ASA ≥ 4 (Lee et al., 2011), ASA II, III, or IV (Santana Santos et al., 2005), ASA I–II or III–V (Bjoro, 2008),
Acute medical conditions included “preoperative medical treatment for cardiovascular or pulmonary problems” (Andersson, Gustafson, Hallberg, 2001), “CHF on admission” and “abnormal BP on admission” (Morrison et al., 2003).
Polypharmacy was defined as “>5” (Bjoro, 2008), “≥ 5” (Juliebo et al., 2009), and “>3 medications” (GOLDENBERG et al., 2006).
BMI (p=0.003), albumin (p=0.26).
The goal of this study was to develop a prediction model for the risk of postoperative delirium (POD). These variables were identified as predictors of POD in the bivariate model, but cut off p-value was not reported in the article.
BMI (p=0.003), albumin (p=0.64).
P-values for the stratified bivariate analysis by dementia status were published by Lee et.al.. The p-values presented in this table were calculated by the author for the entire cohort from available data.
In this study, p <0.15 in the bivariate analysis was the cut-off value for incorporation into the multivariate model, and thus categorized as “significant.”
“abnormal BP” (p=0.12), “abnormal heart rhythm” (p=0.01),”substernal chest pain” (p=0.001), “CHF” (p<0.001), “respiratory compromise” (p=0.59).
Nie et al. reported that different cut-off scores were used to identify cognitive dysfunction depending on educational levels (MMSE <25 for middle school or higher, <21 for elementary school, and <18 for no schooling.). However, baseline bivariate statistics are only reported with comparison of group mean MMSE (p=0.61), and not as a dichotomous variable.