Supplements Special Issue: Payer/Provider Relationships in Oncology
Pathways, Outcomes, and Costs in Colon Cancer: Retrospective Evaluations in 2 Distinct Databases
Objective: The goal of this study was to use 2 separate databases to evaluate the clinical outcomes and the economic impact of adherence to Level I Pathways, an evidence-based oncology treatment program in the treatment of colon cancer.
Patients and Methods: The first study used clinical records from an electronic health record (EHR) database to evaluate survival according to pathway status in patients with colon cancer. Disease-free survival in patients receiving adjuvant treatment and overall survival in patients receiving first-line therapy for metastatic disease was calculated. The second study used claims data from a national administrative claims database to examine direct medical costs and use, including the cost of chemotherapy and of chemotherapy-related hospitalizations according to pathway status.
Results: Overall costs from the national claims database—including total cost per case and chemotherapy costs—were lower for patients treated according to Level I Pathways (on- Pathway) compared with patients not treated according to Level I Pathways. Use of pathways was also associated with a shorter duration of therapy and lower rate of chemotherapy-related hospital admissions. Survival for patients on- Pathways in the EHR database was comparable with that in the published literature.
Conclusion: Results from 2 distinct databases suggest that treatment of patients with colon cancer on-Pathways costs less; use of these pathways demonstrates clinical outcomes consistent with published evidence.
(Am J Manag Care. 2011;17(5 Spec No.):SP45-SP52)
This report assesses the impact of adherence to evidence-based treatment pathways on clinical outcomes, treatment complications, and cost of care in colon cancer.
- This information can be used in practice and policy decisions when evaluating programs to address quality and value in cancer care, including the different data sources and the strengths and limitations of clinical and claims information.
Cancer treatment guidelines,4-6 or clinical pathways, have been developed to standardize treatment and improve quality of care. Little information exists, however, regarding the impact of adherence to pathways on clinical outcomes, treatment complications, and cost of care. Data suggest that the use of clinical pathways in oncology can produce improvements in some areas—including length of hospital stay, complications, and financial outcomes7—and are cost-effective in treating non-smallcell lung cancer.8
Level I Pathways is a set of treatment guidelines established as the foundation of an evidence-based oncology treatment program developed and led by physicians in the US Oncology (The Woodlands, TX) network. It uses only high-level evidence to assess efficacy, toxicity, and cost when recommending therapies. Treatments are updated regularly by a multidisciplinary task force in collaboration with disease research committees and practicing community oncologists. Recommendations are based on lines of therapy and are integrated into the iKnowMed (iKM) electronic health records (EHR) system to provide point-of-care decision support.
The MedStat MarketScan database (Thomson Reuters, New York, NY) represents the inpatient and outpatient healthcare service use of individuals nationwide covered by the benefit plans of large employers, health plans, and government and public organizations. The MarketScan database links paid claims and encounter data to detailed patient information across sites and types of providers over time. The annual medical database includes private sector health data from approximately 100 payers.
Our objective was to conduct 2 separate studies by using the 2 databases to evaluate the clinical outcomes and the economic impact of adherence to Level I Pathways in colon cancer treatment. The first study used clinical records from the iKM EHR database to evaluate survival. To address concern that pathways use may adversely impact quality of care in this study, we examined survival according to pathway status. In the second study, we applied a set of pathway rules to a separate cohort of patients with colon cancer from the MedStat national claims database to examine the cost of chemotherapy and chemotherapy-related adverse events.
Patients and Methods
Patient Identification and Characterization From the EHR Database
The first study was a retrospective cohort design identifying iKM EHR patients with a primary colon cancer diagnosis and initiating an adjuvant line of therapy or a first-line chemotherapy regimen for metastatic disease between July 1, 2006 and June 31, 2007 at US Oncology network practices. Patients who were in the middle of treatment, who were starting with second-line therapy or beyond, or whose regimens were unassessable (as a result of missing or conflicting information) for pathway status were excluded. Using clinical data from the EHR and Pathways reporting center, chemotherapy regimens were electronically assigned a pathway status. Patients were classified as on-Pathway if all regimens during the study period were consistent with the Level I Pathways recommendations for colon cancer. Patients were classified as off- Pathway if treatments were not consistent with pathways or if treatments changed from on- to off-Pathway or vice versa.
Patient Identification and Characterization From a National Claims Database
The second study used MedStat 2005, 2006, and 2007. A retrospective cohort design was used to query this large, commercial insurance database containing data for approximately 4.9 million insured lives with patient characteristics of 24 months of comprehensive fee-for-service coverage (medical and prescription coverage but no capitation) in 2005 and 2006 and at least 1 day of coverage in 2007, younger than age 70, and an active employee or spouse of an active employee. All patients with colon cancer who initiated cytotoxic chemotherapy during the first 6 months of 2006 and had not received chemotherapy in the 12 months before their initial chemotherapy date were identified. Colon cancer was identified by the presence of International Classification of Disase, Ninth Revision (ICD-9) 153.xx in 2006 with 2 or more examination and management physician claims or 1 or more inpatient facility or emergency department facility claims. Treatment was classified as adjuvant if patients had colon resection followed by chemotherapy that began within 60 days after resection; all other patients were considered metastatic. For each patient, the data were organized to produce a timeline of care, including details by dates of surgery, radiation therapy, and chemotherapy. Chemotherapy was categorized into regimens and lines of therapy. The care was compared manually with the 2006 Level I Pathways for colon cancer. Pathway status was calculated on the basis of cycle 1 of each line of therapy using drug combination rules. For example, if a Pathways regimen consisted of 3 drugs (eg, A B C), all had to be present for the patient to be considered on-Pathway. If a drug was omitted (eg, A C only), added (eg, A B C D), or substituted (eg, A B X), the regimen was considered off-Pathway. A nurse and team of pharmacists experienced in clinical oncology and pathways reviewed the timelines. Patients who received any care off- Pathway were classified as being off-Pathway.
Disease-free survival (DFS) and overall survival (OS) were compared between patients treated on-Pathway and off-Pathway by using the Kaplan-Meier method and an intentionto- treat analysis. DFS was calculated in patients starting an adjuvant line of therapy from chemotherapy initiation date to recurrence date, death, or censored for last date of contact. Because of the limited number of patients with stage II disease and pathway treatment changes occurring during the study period, these patients were excluded from the DFS analysis given that the groups could not be reliably separated according to treatment regimen. For patients starting firstline therapy for metastatic disease, OS was calculated from the chemotherapy initiation date to the date of death or last contact. Date of initiation of chemotherapy was defined as the date the chemotherapy regimen was ordered. Because of difficulty in obtaining radiology reports, the date of initiation of subsequent chemotherapy after adjuvant therapy was used to indicate relapse. Date of death, if available, was obtained from the EHR. If no relapse or death was noted, the last date of contact with documented patient vital signs was used.
Cost and Use Analysis
Allowed amounts (before cost sharing) from MedStat were tabulated during the chemotherapy period, which was from the date of the first chemotherapy to the last chemotherapy plus 30 days or until December 31, 2007, whichever came first, with a maximum of 18 months of total observation. Total patient care costs and chemotherapy costs, including oral and infused products, were tabulated. In addition, chemotherapyrelated hospital admissions during the chemotherapy period were tabulated. These were defined by the presence on the claim of a likely chemotherapy-related adverse effect as the primary diagnosis or the primary designation of a cancer diagnosis with 1 of the secondary diagnoses as a chemotherapy-related adverse effect. Statistical significance was calculated by using the Wilcoxon rank sum test.
Clinical Results From an EHR Database
The study included 910 patients from 11 states with a diagnosis of colon cancer who met the EHR eligibility criteria. During the study period, 433 patients (48%) initiated djuvant therapy, and 477 (52%) initiated first-line therapy for metastatic disease. Of the total study population, 756 patients (83%) were treated on-Pathway, and 154 (17%) were treated off-Pathway. All patients had at least 35 months of observation with data through May 31, 2010. Patient characteristics of the adjuvant and metastatic populations according to pathway status are listed in Tables 1 and 2, respectively.
DFS: Adjuvant Chemotherapy
DFS was calculated for the 338 patients with stage III disease initiating adjuvant therapy during the study period. Eighty-five events (recurrence or death) occurred. Approximately 23% of on-Pathway patients (71 of 313) and 56% of off-Pathway patients (14 of 25) experienced an event. Median DFS was 26.9 months for off-Pathway patients and has not yet been reached for on-Pathway patients (Figure 1; P <.05; hazard ratio, 4.98; 95% confidence interval [CI], 2.11 to 11.74). The estimated 1-year, 2-year, and 3-year DFS for on-Pathway and off-Pathway patients was 91% versus 72%, 80% versus 51%, and 73% versus 41%, respectively.
OS: Metastatic Disease
OS was calculated for the 477 patients initiating first-line therapy for metastatic disease. A total of 229 deaths occurred. Approximately 47% of on-Pathway patients (194 of 412) and 54% of off-Pathway patients (35 of 65) died. Median OS for on-Pathway was 26.9 versus 20.1 months for off-Pathway (Figure 2; P = .03; hazard ratio, 1.57; 95% CI, 1.04 to 2.39). The 1-year estimated survival for on-Pathway was 80%; it was 74% for off-Pathway.
Economic Analysis: Cost and Use
From the MedStat national claims database, 220 patients with colon cancer treated with chemotherapy were identified who met study criteria. Table 3 lists patient demographics. Classification of patients receiving adjuvant therapy or as having metastatic disease and as receiving treatment that adhered to Level I Pathways for colon cancer was determined by examining details of therapy as represented in the claims. This examination showed that 41% of patients were treated on-Pathway and 59% were treated off-Pathway. Cost and use results are listed in Table 4. For adjuvant treatment, total costs, chemotherapy costs, and the chemotherapy period were significantly lower for patients on-Pathway (P <.05). Costs per case and per patient per month were lower for patients on-Pathway, which was statistically significant for patients on adjuvant therapy. The chemotherapy-related admissions werelower in both adjuvant and metastatic on-Pathway patients, but this did not achieve statistical significance.