Comparison of clinical characteristics and performance of pneumonia severity score and CURB-65 among younger adults, elderly and very old subjects.
BACKGROUND
Age-related alterations in the clinical characteristics and performance of severity scoring systems for community-acquired pneumonia (CAP) are unknown.


METHODS
Consecutive patients with CAP presenting to the emergency department were prospectively studied. Patients were classified as younger adults (age 18-64 years), elderly (age 65-84 years) and very old subjects (age ≥85 years). Clinical characteristics, complications, outcomes and validity of the pneumonia severity index (PSI) and CURB-65 categories were compared across these three age categories.


RESULTS
Analysis involved 348 (35.3%) younger adult patients, 438 (44.3%) elderly patients and 201 (20.0%) very old patients. Compared with younger adults, elderly and very old patients had a higher burden of comorbidities and a higher incidence of CAP-related complications. The 30-day mortality rate was 5.2% in younger adults, 7.1% in elderly patients and 9.5% in very old patients. The area under the ROC curve (AUCs) for PSI were 0.87 (95% CI 0.77 to 0.97), 0.85 (95% CI 0.803 to 0.897) and 0.69 (95% CI 0.597 to 0.787) and the AUCs for CURB-65 were 0.80 (95% CI 0.67 to 0.93), 0.73 (95% CI 0.65 to 0.82) and 0.60 (95% CI 0.47 to 0.73) in the younger adult, elderly and very old patients, respectively. A modified PSI or CURB-65 excluding the age variable increased the AUC in most age categories. There was no significant effect of age on 30-day mortality after adjusting for other PSI or CURB-65 variables.


CONCLUSIONS
Elderly patients with CAP have more atypical clinical manifestations and worse outcomes. The underperformance of the PSI in elderly patients may be due to the inappropriate weight given to the age variable. A modification of the cut-off point for PSI or CURB-65 to define severe pneumonia may improve the score performance in elderly patients.
Department of Family Medicine, Chang Gung Memorial Hospital, Chiayi, Taiwan.
Jung-Hsiang
JH
Chen
Shy-Shin
SS
Chang
Jason J
JJ
Liu
Rai-Chi
RC
Chan
Jiunn-Yih
JY
Wu
Wei-Chuan
WC
Wang
Si-Huei
SH
Lee
Chien-Chang
CC
Lee
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D017714:Community-Acquired Infections / Q000175:diagnosis / Q000453:epidemiology; D015897:Comorbidity; D004636:Emergency Service, Hospital; D004812:Epidemiologic Methods; D006801:Humans; D008875:Middle Aged; D011014:Pneumonia / Q000175:diagnosis* / Q000453:epidemiology; D011379:Prognosis; D012720:Severity of Illness Index; D013624:Taiwan / Q000453:epidemiology; D055815:Young Adult