The surgical management of kidney stone disease: a population-based time series analysis

Purpose — To evaluate population-based trends in the use of extracorporeal shockwave lithotripsy (SWL), ureteroscopy (URS) and percutaneous nephrolithotomy (PCNL) over the past 20 years, as well as assessing retreatment rate and morbidity from treatment over time.

Methods — Using administrative databases in the province of Ontario, Canada, a population-based cross-sectional time series analysis was performed between July 1, 1991 and December 31, 2010. All SWL, URS and PCNL procedures were identified, along with all hospital readmissions and emergency department (ED) visits within 7 days of treatment. The primary outcome was treatment utilization and the secondary outcomes were the need for ancillary treatment and hospital readmission or ED visit post-treatment. Exponential smoothing and autoregressive integrated moving average models were utilized to assess trends over time.

Results — The authors identified 194,781 kidney stone treatments performed during the study period. Time series modeling demonstrated a significant increase in the utilization of URS over time (25% to 59% of all procedures, p<0.0001) and a reciprocal decrease in the utilization of SWL (69% to 34% of all procedures, p<0.0001). A corresponding significant decrease in the need for ancillary treatment over time (23% to 15%, p<0.0001) and increase in the need for hospital readmission (7% to 11%, p<0.0001) or ED visit (7% to 11%, p=0.0024) post-treatment was also demonstrated.

Conclusions — This population-based study demonstrates a shift in the treatment paradigm with increased use of URS over time and a reciprocal decrease in SWL utilization. The authors also observed a corresponding decrease in ancillary treatment and increase in post-treatment morbidity over time.