Association Between Annual Surgeon Total Thyroidectomy Volume and Transient and Permanent Complications.

IMPORTANCE: Although the association between annual surgeon total thyroidectomy volume and clinical outcomes is well established, published methods typically group surgeons into volume categories. The volume-outcomes association is likely continuous, but little is known about the point at which the annual surgeon procedure volumes begin to be associated with a decrease in complication rates. OBJECTIVE: To model the volume-outcomes association as a continuous function and identify the point at which increasing surgeon volume begins yielding better outcomes. DESIGN, SETTING, AND PARTICIPANTS: A retrospective cohort study was conducted in 2018 to 2019 on 10 546 patients from 2 Kaiser Permanente regions (Northern and Southern California), who underwent total thyroidectomy from January 1, 2008, through December 31, 2015, and were followed up through December 31, 2017. The association between annual surgeon procedure volume and outcomes was modeled with analyses that accounted for an association of unknown form and surgeon-specific effects, after adjusting for sociodemographics, prior-year utilization, and multiple comorbidities. Data were analyzed from October 2018 to April 2019. EXPOSURE: Total thyroidectomy. MAIN OUTCOMES AND MEASURES: Presence or absence of transient and permanent hypoparathyroidism and vocal cord paralysis (VCP) in relation to surgeon volume of total thyroidectomies. RESULTS: Of 10 546 patients in this study, 8500 (81.0%) were male and 4877 (46.2%) aged 45 to 64 years. Surgeons with annual volumes of 1 to 9 total thyroidectomies operated on 2912 patients (27.7%), those with an annual volume of 10 to 19 operated on 3404 (32.6%), and those with an annual volume of 20 or more operated on the remaining 4232 (40.6%). During 2008-2015, a mean of 53.5 (range, 46-198) thyroidectomies were performed each year by surgeons with an annual volume of 40 or more procedures. A generalized additive model showed that the occurrence rates of VCP and hypoparathyroidism began to decrease at annual surgeon procedure volumes of 18.2 (95% CI, 15.0-21.5) and 18.1 (95% CI, 13.8-21.3) procedures per year, respectively. The model revealed a subsequent increase in complication rates for transient VCP. With the use of a refined model, statistically significant decreases were noted in the occurrence rates of complications as annual surgeon volumes increased. Among all 10 546 patients who underwent total thyroidectomy, 632 (6.0%) experienced transient hypoparathyroidism and 170 (1.6%) experienced permanent hypoparathyroidism, whereas 440 (4.2%) experienced transient VCP and 182 (1.7%) experienced permanent VCP. Absolute decreases in complication rates when all surgeons had modeled minimum annual procedure volumes greater than 40 were low, ranging from 0.6% for permanent VCP and hypoparathyroidism to 1.5% for transient hypoparathyroidism. CONCLUSIONS AND RELEVANCE: In this study, occurrence rates of transient and permanent hypoparathyroidism and VCP appeared to decrease as the annual surgeon procedure volume increased, but the absolute decrease may be modest if the affected health system already has low complication rates. Shifting patients to higher-volume surgeons to realize these reductions may be of variable attractiveness in systems with low baseline complication rates.

Clinical outcomes and healthcare use associated with optimal ESRD starts.

OBJECTIVES: To assess the association between optimal end-stage renal disease (ESRD) starts and clinical and utilization outcomes in an integrated healthcare delivery system. STUDY DESIGN: Retrospective observational cohort study in 6 regions of an integrated healthcare delivery system, 2011-2013. METHODS: Propensity score techniques were used to match 1826 patients who experienced an optimal start of renal replacement therapy (initial therapy of hemodialysis via an arteriovenous fistula or graft, peritoneal dialysis, or pre-emptive transplant) to 1826 patients who experienced a nonoptimal start (hemodialysis via a central venous catheter). Outcomes included 12-month rates of sepsis, mortality, and utilization (inpatient stays, total inpatient days, emergency department visits, and outpatient visits to primary care and specialty care). RESULTS: Optimal starts were associated with a 65% reduction in sepsis (odds ratio, 0.35; 95% CI, 0.29-0.42) and a 56% reduction in 12-month mortality (hazard ratio, 0.44; 95% CI, 0.36-0.53). Optimal starts were also associated with lower utilization, except for nephrology visits. Large utilization differences were observed for total inpatient days (9.4 for optimal starts vs 27.5 for nonoptimal starts; relative rate [RR], 0.45; 95% CI, 0.38-0.52) and outpatient visits for specialty care other than nephrology or vascular surgery (12.5 vs 18.3, respectively; RR, 0.62; 95% CI, 0.53-0.74). CONCLUSIONS: Compared with patients with nonoptimal starts, patients with optimal ESRD starts have lower morbidity and mortality and less use of inpatient and outpatient care. Late-stage chronic kidney disease and ESRD care in an integrated system may be associated with greater benefits than those previously reported in the literature.

Risk of Complications after Thyroidectomy and Parathyroidectomy: A Case Series with Planned Chart Review.

OBJECTIVE: To develop a predictive model for the risk of complications after thyroid and parathyroid surgery. STUDY DESIGN: Case series with planned chart review of patients undergoing surgery, 2007-2013. SETTING: Kaiser Permanente Northern California and Kaiser Permanente Southern California. SUBJECTS AND METHODS: Patients (N = 16,458) undergoing thyroid and parathyroid procedures were randomly assigned to model development and validation groups. We used univariate analysis to assess relationships between each of 28 predictor variables and 30-day complication rates. We subsequently entered all variables into a recursive partitioning decision tree analysis, with P < .05 as the basis for branching. RESULTS: Among patients undergoing thyroidectomies, the most important predictor variable was thyroid cancer. For patients with thyroid cancer, additional risk predictors included coronary artery disease and central neck dissection. For patients without thyroid cancer, additional predictors included coronary artery disease, dyspnea, complete thyroidectomy, and lobe size. Among patients undergoing parathyroidectomies, the most important predictor variable was coronary artery disease, followed by cerebrovascular disease and chronic kidney disease. The model performed similarly in the validation groups. CONCLUSION: For patients undergoing thyroid surgery, 7 of 28 predictor variables accounted for statistically significant differences in the risk of 30-day complications; for patients undergoing parathyroid surgery, 3 variables accounted for significant differences in risk. This study forms the foundation of a parsimonious model to predict the risk of complications among patients undergoing thyroid and parathyroid surgery.

Surgeon volume in thyroid surgery: Surgical efficiency, outcomes, and utilization.

OBJECTIVES/HYPOTHESIS: To test our hypothesis that high-surgeon volume is associated with improved surgical efficiency and 30-day outcomes, and lower hospital utilization. STUDY DESIGN: Retrospective observational cohort, 2008-2013. METHODS: A total of 3,135 patients with hemithyroidectomy or total thyroidectomy performed by a high-volume surgeon, propensity score-matched to 3,135 patients with the same procedure performed by a low-volume surgeon. All-cause 30-day complication, mortality, readmission, and emergency department visit rates, proportion of outpatient procedures, cut-to-close time, and length of stay were assessed. RESULTS: Hemithyroidectomies: Compared to low-volume surgeons, high-volume surgeons had fewer readmitted patients (2.7% vs. 7.0%, P < .05), more outpatient procedures (46% vs. 29%, P < .05), and shorter lengths of stay (mean [standard deviation] 16.6 [22.1] vs. 21.7 [27.5] hours, P < .05) and surgical (cut-to-close) times (1.7 [0.7] vs. 2.0 [1.1] hours, P < .05). Total thyroidectomies: High-volume surgeons had lower rates of all surgery-related complications (5.7% vs. 7.5%, P < .05), hypocalcemia (4.9% vs. 7.0%, P < .05), surgical site infections (0.3% vs. 1.0%, P < .05), more outpatient procedures (13% vs. 3%, P < .05), shorter lengths of stay (29.9 [32.8] vs. 39.8 [36.2] hours, P < .05), and cut-to-close times (2.4 [1.1] vs. 3.0 [1.7] hours, P < .05). CONCLUSION: High-volume surgeons improve patient safety and have the potential to contribute to organizational efficiency that may be underutilized in some settings. LEVEL OF EVIDENCE: 4. Laryngoscope, 126:2630-2639, 2016.

Safety of Outpatient Thyroid and Parathyroid Surgery: A Propensity Score-Matched Study.

OBJECTIVE: To test our hypothesis that general and thyroid surgery-specific complications, mortality, and postdischarge utilization for patients undergoing outpatient and inpatient thyroid and parathyroid surgery would not differ when outpatient status was defined as discharge within 8 hours of surgery completion. STUDY DESIGN: Retrospective observational cohort, 2008 to 2013. SETTING: Kaiser Permanente Northern California and Kaiser Permanente Southern California. SUBJECTS AND METHODS: We used a robust set of variables and propensity score methods to match 2362 patients undergoing hemithyroidectomy, total thyroidectomy, or parathyroidectomy surgery as outpatients to 2362 patients undergoing the same procedures as inpatients. Outcomes assessed were 30-day rates of complications, emergency department visits, all-cause hospital readmissions, and mortality. RESULTS: After matching, no statistically significant differences between inpatients and outpatients were found for complication rates or postdischarge utilization. After matching, there was no statistically significant difference between inpatients and outpatients in hematoma rates, which were 0.55% in both groups. In the matched-pair groups, 2 deaths occurred among inpatients (0.09%) and none occurred among outpatients (0.00%), a difference that was not statistically significant. CONCLUSION: Discharge within 8 hours after completion of thyroid and parathyroid surgery is as safe as inpatient surgery.

Occult Uterine Sarcoma and Leiomyosarcoma: Incidence of and Survival Associated With Morcellation.

OBJECTIVE: To estimate the incidence of occult uterine sarcoma and leiomyosarcoma in hysterectomies for leiomyomas and the risk associated with their morcellation. METHODS: We conducted a population-based cohort study. All uterine sarcomas from 2006-2013 in an integrated health care system were identified. Age- and race-specific incidences of occult uterine sarcoma were calculated. Kaplan-Meier survival analysis was performed. Crude and adjusted risk ratios of recurrence and death associated with morcellation at 1, 2, and 3 years were estimated using Poisson regression with inverse probability weighting. RESULTS: There were 125 hysterectomies with occult uterine sarcomas identified among 34,728 hysterectomies performed for leiomyomas. The incidence of occult uterine sarcoma and leiomyosarcoma was 1 of 278 or 3.60 (95% confidence interval [CI] 2.97-4.23) and 1 of 429 or 2.33 (95% CI 1.83-2.84) per 1,000 hysterectomies. For stage I leiomyosarcoma (n=111), eight (7.2%) were power and 27 (24.3%) nonpower-morcellated. The unadjusted 3-year probability of disease-free survival for no morcellation, power and nonpower morcellation was 0.54, 0.19, and 0.51, respectively (P=.15); overall survival was 0.64, 0.75, and 0.68, respectively (P=.97). None of the adjusted risk ratios for recurrence or death were significant except for death at 1 year for power and nonpower morcellation groups combined (6/33) compared with no morcellation (4/76) (5.12, 95% CI 1.33-19.76, P=.02). We had inadequate power to infer differences for all other comparisons including 3-year survival and power morcellation. CONCLUSION: Morcellation is associated with decreased early survival of women with occult leiomyosarcomas. We could not accurately assess associations between power morcellation and 3-year survival as a result of small numbers.