Cost effectiveness of adjuvant bile salt treatment in extracorporeal shock wave lithotripsy for the treatment of gall bladder stones.

The relative cost effectiveness of adjuvant urso and chenodeoxycholic acid treatment in extracorporeal shockwave lithotripsy (ESWL) has been assessed as part of a pragmatic randomised controlled trial of ESWL as a treatment of gall bladder stones. Of the first patients with gall stone volume < 4 cm3 randomised to ESWL in the main trial, 24 were randomised to have ESWL alone and 26 to have adjuvant bile acid treatment, one of whom died before the end of the 12 month follow up period. At 12 months after treatment, differences in gall stone clearance between ESWL alone (3/24 (13%) clear, 5 (21%) referred for surgery) and ESWL and bile acids (6/25 (24%) clear, 2 (8%) referred for surgery) were not significant (p = 0.36, log rank test). Patients in both groups had substantial and significant health gains (according to biliary pain frequency and severity, Nottingham Health Profile scores, visual analogue scale symptom scores, and complications) but there were no significant differences between the groups. Improvements in both groups usually occurred within a few weeks of treatment and were unrelated to gall stone clearance. Costs were greater in the bile salt group (95% confidence intervals for estimated cost difference: 90 pounds to 630 pounds). If the purpose of treatment is symptom relief rather than gall stone clearance then adjuvant bile salt treatment seems to be unnecessary.