Do nursing home residents live longer when they enjoy getting up in the morning?

Background
Feelings of happiness can be beneficial for health in the elderly and are associated with longevity. Depression in nursing home (NH) residents is more common than in the general population, and it can be both a consequence of medical illness and an influencing factor for morbidity and mortality. It is not clear whether life expectancy in NH residents is mainly associated with the presence of positive emotions such as being happy or hopeful, or with the lack of negative emotions such as pessimism and sadness associated with depression.
Objectives
To determine whether the presence of positive emotions, and the lack of negative emotions predict life expectancy in NH residents.
Methods Design: prospective longitudinal study with a baseline measurement of positive and negative emotions, and mortality rate at 21 months follow-up. Participants: a subsample from a study on depression management in 32 Dutch NH units. Exclusion criteria: no informed consent; cognitive inability to respond to the interview. Measurements: Positive Emotions (PE): sum of ‘yes’ answers on 9 positive-items of the Geriatric Depression Scale (GDS), such as “do you find life very exciting?”; Lack of Negative Emotions (LNE): sum of ‘no’ answers on 21 negative-items of the GDS such as “Do you often feel downhearted and blue?”; Co-morbidity: Charlson index; Cognition: Mini Mental State Examination (MMSE)
Procedure: trained interviewers scored the GDS and MMSE; demographical data and co-morbidity were retrieved from medical files. Statistics: Cox Regression was run for survival analysis with age, gender, MMSE and Charlson index as fixed variables, and PE and LNE as predictors for mortality (forward likelihood ratio). Additional survival analyses were run for individual PE, and LNE items.
Results
Of the 250 NH residents included, 158 (63%) were female. The mean age was 79.0 years (SD 11.3), MMSE score was 18.8 (SD 7.5; N=233), and Charlson-index was 2.8 (SD 2.0; N=244). There were 65 deaths (26%). A mean follow-up was 16.8 months. Survival analysis showed that LNE was associated with decreased mortality (adjusted hazard ratio [HR] 0.94 [95% CI: 0.89 to 0.99] P=0.036) whereas PE were redundant (not associated with mortality). Of the LNE-questions, a negative answer to the item “Do you feel that your situation is hopeless?” (HR 0.44 [95% CI: 0.26 to 0.76]; P=0.003) was associated with decreased mortality: 79% and 61% of the residents who answered ‘no’ and ‘yes’, respectively, survived during 21 months. Of the individual PE items, a positive answer to the item “Do you enjoy getting up in the morning?” (HR 0.41 [95% CI: 0.23 to 0.71], P=0.001) was associated with decreased mortality: 80% and 59% of residents who answered ‘yes’ and ‘no’, respectively, survived.
Conclusions
The lack of negative emotions was associated with decreased mortality in NH residents. Residents who did not report that their situation was hopeless and those who enjoyed getting up in the morning lived longer. More research on positive emotions in NH residents is needed due to limited number of positive items of the GDS used in the study.