Accuracy of mortality data for interstitial lung diseases in New Mexico, USA.
BACKGROUND
The sensitivity and accuracy of death certificates and mortality data as sources of population based data on the occurrence of interstitial lung diseases has received limited attention. To determine the usefulness of these data sources, death certificates and mortality data from patients in New Mexico were examined.


METHODS
Patients with an interstitial lung disease were identified from a population based registry. For subjects who had died, diagnostic information from their death certificates and from mortality data was compared with the clinical diagnoses made before death.


RESULTS
Of 385 patients with a clinical diagnosis of an interstitial lung disease, 134 died between October 1988 and August 1994. Death certificates were obtained for 96% of these patients. An interstitial lung disease was listed somewhere on the death certificate for only 46% of the patients, and as an immediate cause of death for only 15%. For the patients with an interstitial lung disease listed somewhere on the death certificate the overall concordance between the diagnoses before death and those on the death certificate was 76%. Mortality data for the State of New Mexico showed a diagnosis of interstitial lung disease to be the assigned cause of death for only 22% of the patients. The overall agreement between the diagnoses made before death and those of the state mortality data was only 21%.


CONCLUSIONS
These results suggest that death certificates and state mortality data are neither sensitive nor accurate for describing the occurrence of interstitial lung diseases. This finding may partly explain the apparently low mortality rates from idiopathic pulmonary fibrosis in the USA compared with other countries.
Coultas
D B
DB
Department of Internal Medicine, University of New Mexico School of Medicine, Albuquerque 87131, USA.
Hughes
M P
MP
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002423:Cause of Death; D003625:Data Collection / Q000592:standards*; D003644:Death Certificates; D005260:Female; D006801:Humans; D017563:Lung Diseases, Interstitial / Q000175:diagnosis / Q000401:mortality*; D008297:Male; D008875:Middle Aged; D009516:New Mexico / Q000453:epidemiology; D011658:Pulmonary Fibrosis / Q000401:mortality; D012042:Registries; D012680:Sensitivity and Specificity