Risk-Adjusted Margin Positivity Rate as a Surgical Quality Metric for Non-Small Cell Lung Cancer

Abstract

Background Incomplete lung cancer resection connotes poor prognosis, the incidence varies with patient demographic, clinical, and institutional factors. We sought to develop a valid, survival-impactful facility-based surgical quality metric which adjusts for related patient demographic and clinical characteristics. Methods Facilities performing resections for patients diagnosed with stage I-IIIA non-small-cell lung cancer in National Cancer Data Base between 2004-2011 were identified. Multivariate logistic regression modeling was used to estimate the expected number of margin-positive cases by adjusting for patient risk-mix and calculate the observed: expected (O/E) ratio for each facility. Facilities were categorized as outperformers (O/E ratio<1, p<.05), non-outliers (p>.05), and underperformers (O/E ratio>1, p<.05); and their characteristics across performance categories were compared by chi-square tests. Multivariate Cox proportional hazard analyses were conducted, adjusting for patient demographic and clinical characteristics. Results A total of 96,324 patients underwent surgery at 809 facilities. The overall observed margin-positive rate was 4.4%. Sixty-one facilities (8%) were outperformers, 644(80%) were non-outliers, and 104(13%) were underperformers. One-third (36%) of National Cancer Institute-designated facilities, 13% Academic-Comprehensive-Cancer-Programs, 5% Comprehensive-Community-Cancer-Programs, and 13% ‘other’ facilities achieved outperforming status but no Community-Cancer-Programs did. Interestingly, 9% of National Cancer Institute-designated facilities and 11% of Academic-Comprehensive-Cancer-program facilities were underperformers. Adjusting for patient demographic and clinical characteristics, outperformers had a 5-year all-cause hazard ratio of 0.88 (95%CI: 0.85–0.91, p<.0001) compared to non-outliers; and 0.80 (95%CI: 0.77–0.84, p<.0001) compared to underperformers. Conclusions Facility performance in lung cancer surgery can be captured by the risk-adjusted margin- positivity rate, potentially providing a valid quality improvement metric.

Institutional-Level Differences in Quality and Outcomes of Lung Cancer Resections in the United States

“…54 High volume does not guarantee high-quality practice; for example, unexpectedly high rates of incomplete resections occur in some highvolume institutions. 27 Although most amenable to measurement and corrective intervention, care-delivery process changes are only useful to the degree that they promote desired outcomes. As soon as a strong link is established between processes and desired outcomes, closer examination of the provider-level and organizationallevel factors driving process differences is necessary to deepen understanding of the relationships among structure, processes, and outcomes.…”

“…Structural categorization alone is insufficient because performance within each structural category is neither uniform nor guaranteed. 27…”

“…Based on existing evidence, we evaluated the following seven adverse quality measures: postoperative mortality at 30, 60, 90, and 120 days [41][42][43] ; resection with positive margins 26,27 ; nonanatomic resection 44 ; resection without lymph node examination (pNX) 45,46 ; resection for stage I and II NSCLC with fewer than 10 examined lymph nodes 47 ; and non-evidence-based use of adjuvant chemotherapy 36,48 or radiation. 33 We defined evidence-based adjuvant chemotherapy as use in patients with pathologic stages IB (T2N0M0 tumors of more than 4 cm), IIA, to IIIB, [34][35][36]48 and we defined any use of adjuvant chemotherapy outside of these stage groups as non-evidence based.…”

“…[23][24][25] In addition to differences in perioperative management and mortality risk, differences in the oncologic quality of care may play a role in the disparate outcomes between patients treated at different institutions. Examples of such differences in oncologic quality include the completeness of resection, 26,27 thoroughness of lymph node examination, [28][29][30] use of anatomic resection, 31,32 and evidence-based use of adjuvant therapy for high-risk patients. [33][34][35][36][37] In theory, eliminating institutional-level survival disparities requires dissemination of best practices across institutions and providers of various characteristics and eliminating disparities in the processes of care.…”

Progress in the Management of Early-Stage Non–Small Cell Lung Cancer in 2017

“…101 2017 brought evidence that directly linked specific process measures (attainment of the NCCNrecommended quality of resection [anatomic resection, negative margins, examination of N1 lymph nodes and examination of a minimum of three mediastinal nodal stations] and the ratio of the observed-to-expected rate of incomplete resection) to survival: two readily measured surgical quality benchmarks. 102,103 Adjuvant and Neoadjuvant Therapies Treatment with 4 cycles of cisplatin-based chemotherapy following complete surgical resection in patients with stage II-IIIA NSCLC remains the standard of care in the adjuvant setting, offering an approximately 5% overall survival (OS) benefit. 26,104 Patients with stage I disease and tumors >4 cm likely also derive benefit from adjuvant chemotherapy.…”