In a Cox model , the association between lower UPSIT score and mortality ( hazard ratio [ HR ] = 1.07 per point interval , 95 % confidence interval [ CI ] = 1.05-1 .08 , p < 0.001 ) persisted after controlling for age , gender , education , ethnicity , language , modified Charlson medical comorbidity index , dementia , depression , alcohol abuse , head injury , smoking , body mass index , and vision and hearing impairment ( HR = 1.05 , 95 % CI = 1.03-1 .07 , p < 0.001 ) .