Geographic Variation in the Quality of Secondary Prevention for Nephrolithiasis.

Objective: To examine the variation in the quality of secondary prevention for nephrolithiasis across health care markets.
Methods: Using analytical files from Litholink Corporation (2003-2012), we identified adults with nephrolithiasis and abnormal urine biochemistries on 24-hour urine collection. After assigning all patients to a hospital referral region (HRR), we determined the proportion of patients in each HRR who underwent on-treatment follow-up testing (our measure of quality). We then fitted multivariate hierarchical regression models to quantify the amount of variation in this proportion across HRRs. Finally, we examined for associations between a patient's odds of on-treatment follow-up testing and the supply of primary care and specialist physicians in an HRR.
Results: The mean rate on-treatment follow-up testing was exceedingly low at only 11.9%. This rate has been stable over time. There was fourfold variation in this rate across HRRs from as little as 6.6% to as high as 23.4%. Those HRRs with higher on-treatment follow-up testing rates tended to have a wealthier and more educated population (P = .01). Receipt of on-treatment follow-up testing was not associated with the number of specialists per capita.
Conclusion: Wide geographic variation exists in the quality of secondary prevention for patients with nephrolithiasis. Given that current guidelines recommend on-treatment follow-up testing, efforts to increase its uptake are needed.
(Published by Elsevier Inc.)