Hospital-activity data inaccurate for determining spread-of-disease at diagnosis for non-small cell lung cancer.
OBJECTIVE
Accurate information on spread-of-disease at diagnosis would increase the usefulness of hospital-activity data for cancer research. This study evaluates the accuracy of codes recorded in hospital-activity data to assign spread-of-disease at diagnosis for non-small cell lung cancer (NSCLC).


METHODS
The reference (gold) standard was TNM stage as assigned at a multi-disciplinary meeting. To allow comparison with hospital-activity data, TNM stage was mapped to spread-of-disease (local, regional, distant). Sensitivity, specificity and positive-predictive values were stratified by whether the patient had surgery.


RESULTS
Data from the reference standard and hospital-activity database were available for 2,184 patients. According to the reference standard, local disease was present for 57.0% of surgical patients and 12.6% of non-surgical patients at diagnosis. Hospital-activity data over-estimated patients with local disease (surgical: 71.9%, non-surgical: 48.5%). There was a corresponding underestimation of distant spread-of-disease: surgical (reference standard: 4.0%, hospital-activity data: 2.7%); non-surgical (reference standard: 45.9%, hospital-activity data: 36.8%). This meant that hospital-activity data had good sensitivity but poor specificity for local disease; and poor sensitivity, but good specificity for metastatic disease.


CONCLUSIONS
Secondary diagnosis codes in hospital activity data do not accurately capture spread-of-disease at diagnosis for patients with non-small cell lung cancer; even when the clinical notes contain TNM clinical stage as documented at a multidisciplinary meeting.


CONCLUSIONS
Changes are needed to coding rules, and the ICD codes themselves, to allow for coding of regional and distant spread without specification of the precise site.
School of Population Health, University of Queensland, Victoria.
Bridie
B
Thompson
Melanie
M
Watson
Rayleen
R
Bowman
Kwun
K
Fong
Michael
M
Coory
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002289:Carcinoma, Non-Small-Cell Lung / Q000175:diagnosis / Q000473:pathology* / Q000601:surgery; D005260:Female; D006753:Hospital Records / Q000706:statistics & numerical data*; D006801:Humans; D038801:International Classification of Diseases / Q000592:standards* / Q000706:statistics & numerical data; D008175:Lung Neoplasms / Q000175:diagnosis / Q000473:pathology* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D009362:Neoplasm Metastasis / Q000175:diagnosis*; D009367:Neoplasm Staging / Q000592:standards*; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D055815:Young Adult