Ann Intern Med. 2014 Nov 4;161(9):659-67. doi: 10.7326/M13-2908.

Dietary and pharmacologic management to prevent recurrent nephrolithiasis in adults: a clinical practice guideline from the American College of Physicians.

Qaseem A, Dallas P, Forciea MA, Starkey M, Denberg TD; Clinical Guidelines Committee of the American College of Physicians.

PMID: 25364887

Americas: June 9th 9 pm Eastern

EU/Africa: June 10th 8 pm GMT

Thanks Hector Madariaga for curating both chats. 

 

Summary (written by Swapnil Hiremath)

The ACP guideline process

NephJC returns to the critical appraisal of guidelines, this time with the significant effort put by the team from the American College of Physicians (ACP), which was published in the Annals recently. Some background of the ACP guideline development process will be useful – after all, as they themselves say, they are not produced "by a bunch of old guys sitting around a board room". Indeed, they have been doing these since 1981, and the full list can be found here. The ACP guideline development process is also published (free paper, available here). Of the three pathways that guideline development could follow, some are commissioned by the Agency for Healthcare Research and Quality (AHRQ), some by speciality societies and lastly, some by the ACP from its own funds. This particular CPG was done the third way, using ACP funds. They use a slightly modified GRADE approach in evaluating the evidence, suggesting methodological rigor.

Table 1 from Qaseem et al Annals of Internal Med, 2014

Table 1 from Qaseem et al Annals of Internal Med, 2014

The ACP CPG on Nephrolithiasis

As for their previous CPGs, the ACP CPG committee conducted a systematic review to prepare this guidance. The overall purpose was ostensibly to present the evidence and provide clinical recommendations on the comparative effectiveness and safety of preventive dietary and pharmacologic management of recurrent nephrolithiasis in adults. They set up to answer 6 key questions:

  1. Do results of baseline stone composition and blood and urine chemistries predict the effectiveness of diet and/or pharmacologic treatment on final health outcomes and intermediate stone outcomes, as well as reduce adverse effects?
  2. Do results of follow-up blood and urine biochemistry measurements predict final health outcomes and intermediate stone outcomes in adults being treated to prevent recurrence?
  3. What is the effectiveness and comparative effectiveness of different dietary therapies on final health outcomes and intermediate stone outcomes?
  4. What is the evidence that dietary therapies to reduce risk for recurrent stone episodes are associated with adverse effects?
  5. What is the effectiveness and comparative effectiveness of different pharmacologic therapies on final health outcomes and intermediate stone outcomes?
  6. What is the evidence that pharmacologic therapies to reduce risk for recurrent stone episodes are associated with adverse effects?

Unequivocally, these are extremely important questions, so what happened next is interesting. Table 2 is depressing in terms of what they found: very little evidence - or rather, low quality and insufficient evidence. As a result, they made only two weak recommendations - increase fluid intake to 2 litres, and if that doesn't work, use thiazide diuretics, allopurinol or citrate.

Figure from Qaseem et al, Annals of Int med, 2014

Figure from Qaseem et al, Annals of Int med, 2014

The Aftermath

For any clinician who deals with patients with recurrent kidney stones, these recommendations do not seem very helpful. And there are are other problems highlighted by

- comments/correspondence in Annals

- Articulate, and thoughtful blog posts by the eminent Stone expert, Fredric Coe on recommendation 1 and recommendation 2

- A scathing rebuke written by Stone Former and Treater extraordinaire, David Goldfarb aka @weddellite

- Some more background provided by Joel on PBFluids

- The American Urological Association Guidelines, released earlier in 2014 (PDF Link)

Experts or Outsiders?

One of the major issues this highlights is - who should be making and writing these guidelines? Content experts are indeed experts, but they may be too invested in the topic perhaps - and often may have financial or other conflicts of interests. On the other hand, using non-content experts can lead to some problems highlighted above. Moreover, the rise to prominence of the guideline process has lead to this becoming a contentious issue. Witness the broad and sparse recommendations of JNC 2014 compared to the practical and detailed - and near-simultaneous release of the ASH/ISH guidelines (PDF link alert). Similarly the ACP guidelines on screening for CKD were not received with welcome arms by the nephrology community. 
We may not have an answer to many of these issues, but join us for what promises to be an exciting twitter discussion next week.

Banner image credit Annie Cavanagh, used under Creative Commons License, available at WellcomeImages.org