Objective: To compare the cumulative probability of survival in a cohort of patients with chronic obstructive pulmonary disease (COPD) attended at primary and tertiary levels of health care.
Patients and method: A cohort study was carried out at the Department of Pneumology of the Centro Medico Nacional La Raza (Mexico DF) on 87 of the 114 patients with confirmed diagnosis of COPD. All patients followed a 6-month physical activity and educational program. Patients underwent the COPD diagnostic tests recommended by the American Thoracic Society and were randomized and distributed in 2 groups: Group A had 44 patients who received tertiary care, and Group B had 43 who received primary care. Follow up lasted from 1993 to 2001. Exacerbations, hospital admissions, exercise duration, hospital stay, and death or study abandonment were recorded for all patients. Respiratory function tests were performed annually. Annual and total mortality, distribution by sex, loss in life expectancy, mean age at death, and cumulative probability of survival were analyzed.
Results: No differences were found between the groups in population or initial characteristics. Respiratory function declined in both groups, although the decline was smaller in Group A: mean (SD) forced expired volume in 1 second, 8.93% (8.72%) compared with 17.71% (2.51%) and annual drop in blood pressure of 1.39 mm Hg compared with 1.95 mm Hg. Annual exacerbations were 0.23 in Group A compared with 2.07 in Group B; hospitalizations, 0.06 compared with 0.92, and length of stay, 15.76 days compared with 17.32 days. Mean age at death was 66.12 compared with 60.6; loss of life expectancy was 13.88 years lost compared with 19.4, and the cumulative probability of survival was 0 compared with 0.224.
Conclusions: There are many reasons for the differences found: better medical management, health education, and family involvement at the tertiary level. These factors, included in international COPD guidelines, must be incorporated into primary health care.