Clinical and Economic Outcomes for Gastric Cancer Patients Treated with Gastrectomy at Centres With and Without Cancer Surgery Designation in Ontario

Gastric cancer places high clinical and economic burden on healthcare systems. This study compares patient outcomes between centres with and without cancer surgery centre designation (CSCD). Gastric cancer patients diagnosed 2002-2014, and treated with gastrectomy were identified using Ontario’s linked administrative databases. Outcomes included 90-day mortality, overall survival, and healthcare costs. Institutions with CSCD (n =1,436) were associated with lower 90-day mortality (OR 0.70, 95% CI 0.52-0.94, p=0.02), and similar overall survival (HR 0.94, 95% CI 0.85-1.04, p=0.24) as institutions without CSCD (n = 1,494). The cost analysis included 1,143, and 1,256 patients treated at institutions with and without CSCD, respectively. Adjusted mean monthly costs were $3,310 (95$2,384-$4,595) for the CSCD group, and$3,430 (95% CI $2,469-$4,765) for the non-CSCD group (p=0.36). Treatment at institutions with CSCD may result in lower 90-day mortality, and similar overall survival, and costs of care for gastric cancer patients.M.Sc

Validating an algorithm to identify metastatic gastric cancer in the absence of routinely collected TNM staging data

Abstract Background Accurate TNM stage information is essential for cancer health services research, but is often impractical and expensive to collect at the population-level. We evaluated algorithms using administrative healthcare data to identify patients with metastatic gastric cancer. Methods A population-based cohort of gastric cancer patients diagnosed between 2005 and 2007 identified from the Ontario Cancer Registry were linked to routinely collected healthcare data. Reference standard data identifying metastatic disease were obtained from a province-wide chart review, according to the Collaborative Staging method. Algorithms to identify metastatic gastric cancer were created using administrative healthcare data from hospitalization, emergency department, and physician billing records. Time frames of data collection in the peri-diagnosis period, and the diagnosis codes used to identify metastatic disease were varied. Algorithm sensitivity, specificity, and accuracy were evaluated. Results Of 2366 gastric cancer patients, included within the chart review, 54.3% had metastatic disease. Algorithm sensitivity ranged from 50.0- 90%, specificity ranged from 27.6 - 92.5%, and accuracy from 61.5 - 73.4%. Sensitivity and specificity were maximized when the most conservative list of diagnosis codes from hospitalization and outpatient records in the six months prior to and the six months following diagnosis were included. Conclusion Algorithms identifying metastatic gastric cancer can be used for research purposes using administrative healthcare data, although they are imperfect measures. The properties of these algorithms may be generalizable to other high fatality cancers and other healthcare systems. This study provides further support for the collection of population-based, TNM stage data

Additional file 1: of Validating an algorithm to identify metastatic gastric cancer in the absence of routinely collected TNM staging data

Table S1. Included diagnoses, ICD-9 and 10 codes used to identify metastatic disease for the different algorithms. (DOCX 15 kb