[Case volume and complications after thyroid gland surgery in Germany: an analysis of routine data from 48,387 AOK patients]

BACKGROUND

Many studies showed that hospital and surgeon volume have a significant influence on the complication rates of thyroid surgery. The present study investigates whether this relationship applies in subtotal as well as total lobe resections. Furthermore, it is still unclear which threshold for the hospital-related case volume can be determined, above which the risk of complications lies below the current national average.

MATERIAL AND METHODS

The study was based on nationwide routine data for persons insured with the Local General Sickness Fund (AOK) who had undergone thyroid surgery in 2014-2016. Permanent vocal cord palsy, bleeding and wound infection needing revision were recorded using indicators. The effect of the case volume on the indicators and the case number threshold was determined using logistic regression.

RESULTS

Permanent vocal cord palsy was observed in 1.3% and bleeding or wound infections needing revision in 1.6% and 0.3% of the cases. Compared to hospitals with >450 surgeries per year, the risk of permanent vocal cord palsy in hospitals with fewer than 201, 101 and 51 surgeries was significantly increased (OR [95% CI]: 1.5 [1.1-2.1]; 1.5 [1.1-2.1]; 1.8 [1.3-2.5]). The threshold needed to achieve a risk for permanent vocal cord palsy below the national average (1.3%) was 265 thyroid surgeries per year (95% CI: 110-420). For bleeding or wound infection in need of revision, no association between volume and outcome was found.

CONCLUSION

The present study showed that the risk of postoperative permanent vocal cord palsy decreased with increasing case volume. The broad confidence interval of the threshold makes clear case volume recommendation difficult. In order that the risk for a postoperative permanent vocal cord palsy is not likely above the national average, the annual case volume should reach 110 thyroid interventions.

Hospital volume and outcome in inguinal hernia repair: analysis of routine data of 133,449 patients

Introduction

Inguinal hernias are repaired using either open or minimally invasive surgical techniques. For both types of surgery it has been demonstrated that a higher annual surgeon volume is associated with a lower risk of recurrence. This present study investigated the volume-outcome implications for recurrence operations, surgical complications, rate of chronic pain requiring treatment, and 30-day mortality based on the hospital volume.

Materials and methods

The data basis used was the routine data collected throughout the Federal Republic of Germany for persons insured by the Local General Sickness Fund “AOK” who had undergone inpatient inguinal hernia repair between 2013 and 2015. Complications were recorded by means of indicators. Hospitals were divided into five groups on the basis of the annual caseload volume: 1–50, 51–75, 76–100, 101–125, and ≥ 126 inguinal hernia repairs per year. The effect of the hospital volume on the indicators was assessed using multiple logistic regression.

Results

133,449 inguinal hernia repairs were included. The incidence for recurrence operations was 0.95%, for surgical complications 4.22%, for chronic pain requiring treatment 2.87%, and for the 30-day mortality 0.28%. Low volume hospitals (1–50 and 51–75 inguinal hernia repairs per year) showed a significantly increased recurrence risk compared to high volume hospitals with ≥ 126 inguinal hernia repairs per year (odds ratio: 1.53 and 1.24). No significant correlations were found for the other results.

Conclusions

The study gives a detailed picture of hospital care for inguinal hernia repair in Germany. Furthermore, it was noted that the risk of hernia recurrence decreases in line with a rising caseload of the treating hospital.