When, for How Long and in Whom Should Medical Expulsive Therapy be Used? PATIENTS with ureteral stones are typically offered the 3 options of medical expulsive therapy, shock wave lithotripsy and ureteroscopy. For medical expulsive therapy they are counseled on the likelihood of spontaneous stone passage based on the size and location of the stone.1 Their prior experience with stone passage, including how big, how much pain, how much impact on quality of life, factors into the discussion. Typically a trial of medical expulsive therapy may be tried for 4 to 6 weeks if the patient’s severity of symptoms allows and there is no compromise in renal function. In this issue of The Journal Dauw et al (page 673) use a claims based algorithm and propensity score matching to evaluate the indirect costs of medical expulsive therapy vs early endoscopic treatment using short-term disability claims as a surrogate for indirect costs.2 As the probability of filing a shortterm disability claim was low in both groups (6% to 17%), one wonders if other measures of socioeconomic impact, such as the filing of family medical leave forms by the patient or relatives, would also be important to evaluate. Indeed, the availability of short-term disability may impact a patient’s decision of whether to proceed with early intervention. This issue in itself confounds the analysis in this study.

Unfortunately with claims based data the most critical prognostic factors for stone passage are not available, namely stone size and stone location. Although propensity score matching controls for measured confounders between the 2 groups, it cannot account for the potential selection bias based on nonrecorded confounders, in this case stone size and location. As such, one could hypothesize that there would be a tipping point based on stone size and location, for which early endoscopic management with shock wave lithotripsy would be more cost-effective than medical expulsive therapy in terms of indirect and direct costs. Indeed, a recent study suggests that for proximal ureteral calculi, early shock wave lithotripsy is associated with superior outcomes as measured by the number of days to a stone-free result and the need for re-treatment or secondary procedures.3 Manoj Monga* Stevan Streem Center for Endourology & Stone Disease Glickman Urological & Kidney Institute Cleveland Clinic Cleveland, Ohio *Financial interest and/or other relationship with Cook Urological, Bard, Olympus, Histosonics, Coloplast and Fortec.

REFERENCES 1. Miller OF and Kane CJ: Time to stone passage for observed ureteral calculi: a guide for patient education. J Urol 1999; 162: 688. 2. Dauw CA, Kaufman SR, Hollenbeck BK et al: Expulsive therapy versus early endoscopic stone removal in patients with acute renal colic: a comparison of indirect costs. J Urol 2014; 191: 673. 3. Kumar A, Mohanty NK, Jain M et al: A prospective randomized comparison between early (