Association of Compliance With Process-Related Quality Metrics and Improved Survival in Oral Cavity Squamous Cell Carcinoma

Abstract

Importance: Quality metrics for patients with head and neck cancer are available, but it is unknown whether compliance with these metrics is associated with improved patient survival.

Objective: To identify whether compliance with various process-related quality metrics is associated with improved survival in patients with oral cavity squamous cell carcinoma who receive definitive surgery with or without adjuvant therapy.

Design, setting, and participants: A retrospective cohort study was conducted at a tertiary academic medical center among 192 patients with previously untreated oral cavity squamous cell carcinoma who underwent definitive surgery with or without adjuvant therapy between January 1, 2003, and December 31, 2010. Data analysis was performed from January 26 to August 7, 2015.

Interventions: Surgery with or without adjuvant therapy.

Main outcomes and measures: Compliance with a collection of process-related quality metrics possessing face validity that covered pretreatment evaluation, treatment, and posttreatment surveillance was evaluated. Association between compliance with these quality metrics and overall survival, disease-specific survival, and disease-free survival was calculated using univariable and multivariable Cox proportional hazards analysis.

Results: Among 192 patients, compliance with the individual quality metrics ranged from 19.7% to 93.6% (median, 82.8%). No pretreatment or surveillance metrics were associated with improved survival. Compliance with the following treatment-related quality metrics was associated with improved survival: elective neck dissection with lymph node yield of 18 or more, no unplanned surgery within 14 days of the index surgery, no unplanned 30-day readmissions, and referral for adjuvant radiotherapy for pathologic stage III or IV disease. Increased compliance with a "clinical care signature" composed of these 4 metrics was associated with improved overall survival, disease-specific survival, and disease-free survival on univariable analysis (log-rank test; P < .05 for each). On multivariable analysis controlling for pT stage, pN stage, extracapsular spread, margin status, and comorbidity, increased compliance with these 4 metrics was associated with improved overall survival (100% vs ≤50% compliance: adjusted hazard ratio [aHR], 4.2; 95% CI, 2.1-8.5; 100% vs 51%-99% compliance: aHR, 1.7; 95% CI, 1.0-3.1), improved disease-specific survival (100% vs ≤50% compliance: aHR, 3.9; 95% CI, 1.7-9.0; 100% vs 51%-99%: aHR, 1.3; 95% CI, 0.6-2.9), and improved disease-free survival (100% vs ≤50% compliance: aHR, 3.0; 95% CI, 1.5-5.8; 100% vs 51%-99% compliance: aHR, 1.6; 95% CI, 0.9-2.7).

Conclusions and relevance: Compliance with a core set of process-related quality metrics was associated with improved survival for patients with surgically managed oral cavity squamous cell carcinoma. Multi-institutional validation of these metrics is warranted.

Figure 1. Association Between Compliance With the “Clinical Care Signature” and Improved Survival on Univariable Analysis

A, Kaplan-Meier estimate of overall survival (P < .05; log-rank test). B, Kaplan-Meier estimate of disease-specific survival (P < .05; log-rank test). C, Kaplan-Meier estimate of disease-free survival (P < .05; log-rank test). The clinical care signature is a small group of process-related care practices associated with the overall quality of care. All estimates are stratified by compliance with the clinical care signature quality metrics (100% vs 51%-99%. vs 50%).

Figure 2. Association Between Compliance With the “Clinical Care Signature” and Improved Survival on Multivariable Analysis

A, Cox multivariable survival analysis for overall survival (100% vs ≤50%: adjusted hazard ratio [aHR], 4.2; 95% CI, 2.1-8.5; 100% vs 51%-99%: aHR, 1.7; 95% CI, 1.0-3.1). B, Cox multivariable survival analysis for disease-specific survival (100% vs ≤50%: aHR, 3.9; 95% CI, 1.7-9.0; 100% vs 51%-99%: aHR, 1.3; 95% CI, 0.6-2.9). C, Cox multivariable survival analysis for disease-free survival (100% vs ≤50%: aHR, 3.0; 95% CI, 1.5-5.8; 100% vs 51%-99%: aHR, 1.6; 95% CI, 0.9-2.7). The clinical care signature is a small group of process-related care practices associated with the overall quality of care. All estimates are stratified by compliance with the clinical care signature quality metrics after adjusting for pT stage, pN stage, extracapsular spread, margin status, and comorbidity.