Example

 

“Surgeon eligibility: participating surgeons must either be a consultant orthopaedic surgeon or perform the procedure under direct consultant supervision. To deliver KR (knee replacement) within KARDS (Knee Arthroplasty versus Joint Distraction for Osteoarthritis), a surgeon must have performed ≥10 KRs in the past 12 months as the primary surgeon. To deliver KJD (knee joint distraction) within KARDS, they must have performed ≥10 external fixations during their career as the primary surgeon or completed a limb reconstruction fellowship" [221]. 

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Explanation

 

For all types of trials, it is important to plan the eligibility criteria for trial sites, and to consider the characteristics of the treatment providers intended to deliver both the experimental and comparator interventions. One reason for this is logistical, as the complexity of running a trial increases with the number of sites (so each site should preferably be able to include a reasonable number of trial participants). However, for many trials, it is also important to align the experience of the treatment providers in the trial with that of the expected treatment providers in routine clinical practice.

 

For some pharmacological interventions it is important that treatment providers have specialist training or that the intervention is delivered in specialised settings, e.g., within oncology. More commonly, issues related to the training, qualifications, and experience of treatment providers and the setup of sites arise in trials of nonpharmacological interventions. For trials of nonpharmacologic interventions, such as surgery or rehabilitation, it is often important to also report the eligibility criteria for sites where the interventions will be administered and for the individuals who will deliver the intervention [222, 223]. 

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Patient outcomes can be associated with hospital and care provider volume (i.e., the number of patients seen by a care provider or treated in a hospital) [223]. A systematic review of 135 trials found that 71% observed a positive association between hospital volume and outcomes and 70% observed an association between care provider volume and outcomes [224]. Different levels of expertise of care providers in each trial group can bias treatment effect estimates [225]. 

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Furthermore, a nonpharmacological intervention might be found to be safe and effective in a trial performed in high-volume sites by high-volume care providers, but could have different results in low-volume sites. For example, in an analysis of Medicare National Claim files of 167,208 patients undergoing coronary stent surgery, patients treated by high-volume physicians and at high-volume centres experienced better outcomes compared with those treated by low-volume physician at low-volume centres [226]. 

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Eligibility criteria for care providers and centres in nonpharmacological trial protocols are often poorly reported. Reviews of two samples of 108 and 292 trial protocols from 2016 found that centre eligibility criteria (and criteria for those performing the intervention) were reported in 30% to 38% of protocols, respectively [9, 10]. 

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A description of care providers who will be involved in the trial, as well as details of the sites where participants will be treated, are essential to enable study personnel to apply these criteria consistently throughout the trial. This information also helps readers appraise the risk of bias and the applicability of the trial results to other populations [223]. Eligibility criteria for sites typically relate to site volume for the procedure under investigation or similar procedures. Eligibility of care providers might include professional qualifications, years in practice, number of interventions performed, skill as assessed by number and type of complication when performing the intervention, and specific training before trial initiation. Eligibility criteria should be justified because they will influence the applicability of the trial results.

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Summary of key elements to address

If applicable:

• Eligibility criteria for sites (e.g., site volume for surgical procedure)

• Eligibility criteria for individuals delivering the interventions (e.g., surgeons, physiotherapists), such as professional qualifications, years in practice, skills, or validation of specific training before trial initiation