Control, Fludrocortisone or Midodrine for the treatment of Orthostatic Hypotension: CONFORM-OH pilot RCT and economic evaluation.

Background: Orthostatic hypotension is a significant drop in blood pressure upon standing upright. It is very common and can result in symptoms such as postural dizziness, fainting and falls. Within the United Kingdom National Health Service, there are three principal treatments: non-drug therapies, and two medications - fludrocortisone or midodrine. Despite this we do not know which treatments are the most effective, nor whether they are cost-effective. Objective: Evaluate the feasibility of a randomised trial to evaluate the clinical and cost-effectiveness of fludrocortisone and midodrine in comparison to non-drug therapies for the treatment of orthostatic hypotension. Design: A 10-month pilot of a pragmatic, open-label, randomised, prospective, superiority, multiarm, multistage clinical trial. The pilot evaluated recruitment, attrition, crossover and quality of outcomes. Setting: Falls and Syncope, Movement Disorder, Geriatrics, and Cardiology clinics in United Kingdom National Health Service secondary care. Participants: Adults with symptomatic orthostatic hypotension. Interventions: Control: Non-drug therapies (conservative management). Interventions: Conservative management plus fludrocortisone (50-400 mcg daily) or conservative management plus midodrine (5-30 mg daily). Main outcome measures: Recruitment: Target was 40-64 participants from 14 sites. Attrition target: ≤ 15% participants withdraw before the primary end point. Crossover: To determine the rates of crossover between intervention arms. Outcome data: Assess the quality and completeness of outcomes. Other important outcomes included feedback via questionnaire and interview from sites and participants. Results: Two hundred and eighty-two patients were screened for eligibility during the pilot; of these, 13 were recruited from 4 of 9 open sites. Current or recent use of one of the study medications accounted for 120 (52%) exclusions due to ineligibility. At the primary end point of 6 months, 10 of the 13 participants (77%) remained in the study. Of those, completion rates for primary and secondary outcomes were 100%, except for the falls diaries, which was 60%. Feedback from sites revealed that redeployment of clinical and research staff due to COVID-19 negatively impacted on site opening and screening for eligible participants. Adapting the protocol to make it more flexible for remote clinics and more pragmatic for clinical use did not improve recruitment. Limitations: The sample size is too small to provide a reliable estimate of attrition and crossover rates for future studies. Conclusions: This study was not feasible in its current design. COVID-19 had an impact on staffing and site opening, while the exclusion criteria limited recruitment. Future work: To answer the research question, novel trial designs are needed. Funding: This synopsis presents independent research funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme as award number NIHR127385.