. Author manuscript; available in PMC: 2018 May 9.

Published in final edited form as: Otolaryngol Head Neck Surg. 2014 Jan 6;150(3):494–500. doi: 10.1177/0194599813518164

Table 3.

Physical Function: Comparison of the Functional and Charlson Indexes.

	Functional Index	Charlson Index
Spearman Correlation	−0.53^*	−0.39^*
Adjusted coefficient of determination (R²)	0.27	0.17
Bootstrapped distribution of the adjusted coefficient of determination (mean±standard error)	0.27±0.05^**	0.17±0.05^**

Spearman correlation between each Index and the SF-36 Physical Function. Negative correlations indicate that as the number of comorbidities increases (higher Index score) the level of self-reported physical function decreases (lower SF-36 Physical Function score). Coefficients of determination generated by multiple linear regression, adjusted for age, gender, race, ethnicity, and apnea-hypopnea index.

Each correlation significantly different from zero, p<0.001.

^**

Difference between Indexes statistically significant, p<0.001.