Severity assessment of lower respiratory tract infection in elderly patients in primary care

Background: Simple markers for evaluating the severity of lower respiratory tract infections (LRTI) in primary care are lacking. It is of value to exa mine whether the information available to the primary care physician during a patient's initial visit can be used to assess the severity of LRTI. Methods: The associations between different baseline variables and outcomes (survival within or more than 30 days) were investigated prospectively in a series of 950 home-living patients 65 years or older with severe LRTI tha t their primary care physicians suspected to be pneumonia. Results: Twenty-one men and 17 women died (4.1%) within 30 days. According to univariate analysis, the following parameters differed (P < .01) between the fatalities and survivors: acute aggravation of a coexisting illness, a ge, respiratory rate, white blood cell count, and C-reactive protein (CRP) level. According to Cox forward stepwise regression analysis (P = .01 for e ntry and .05 for removal), acute aggravation of a concurrent illness, respi ratory rate (greater than or equal to 25/min), and CRP concentration (great er than or equal to 100 mg/L) were independently associated with death. The mortality rate was 2.2% if the patients had none or only I of the independ ent risk factors and 20% if they had all 3 risk factors. Conclusions: Preceding aggravation of a concurrent illness and respiratory rate of 25/min or higher, together with an elevated serum CRP level (greate r than or equal to 100 mg/L), can be used as simple markers for identifying patients with the highest risk for LRTI and improve management decisions a mong elderly people in primary care.