Open AccessThe value of complementing administrative data with abstracted information on smoking and obesity: A study in kidney cancer
Author(s) -
Madhur Nayan,
Robert J. Hamilton,
Antonio Finelli,
Peter C. Austin,
Girish S. Kulkarni,
David N. Juurlink
Publication year - 2017
Publication title -
canadian urological association journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.477
H-Index - 38
eISSN - 1920-1214
pISSN - 1911-6470
DOI - 10.5489/cuaj.4569
Subject(s) - medicine , hazard ratio , proportional hazards model , confidence interval , cancer , comorbidity , cancer registry , statistic , obesity , body mass index , statin , database , statistics , mathematics , computer science
Variables, such as smoking and obesity, are rarely available in administrative databases. We explored the added value of including these data in an administrative database study evaluatingthe association of statin use with survival in kidney cancer.Methods: We linked administrative data with chart-abstracted data on smoking and obesity for 808 patients undergoing nephrectomy for kidney cancer. Base models consisted of variables from administrative databases (age, sex, year of surgery, and different measures of comorbidity [to compare their sensitivity to smoking and obesity data]); extended models added chart-abstracted data. Wecompared coefficients for statin use with overall (OS) and cancer-specific survival (CSS), and used the c-statistic and net reclassification improvement (NRI) to compare predications of five-year survival obtained from Cox proportional hazard models.Results: The coefficient for statin use changed minimally following addition of abstracted data (<6% for OS, <2% for CSS). Base models performed similarly for OS, with c-statistics of 0.75 (95% confidence interval [CI] 0.72‒0.79) for Charlson score and 0.73 (95% CI 0.69‒0.78) for John Hopkins Aggregated Diagnosis Groups score. After including abstracted data, c-statistics modestly improved (change <0.02); CSS demonstrated similar findings. NRIs were 0.210 (95% CI 0.062‒0.297) and 0.186 (-0.031‒0.387) when using the Charlson score, and 0.207 (0.068‒0.287) and 0.197 (0.007‒0.399) when using the Aggregated Diagnosis Groups score, for OS and CSS, respectively.Conclusions: The inclusion of data on smoking and obesity marginally influences survival