Clarithromycin and endoscopic sinus surgery for adults with chronic rhinosinusitis with and without nasal polyps: study protocol for the MACRO randomised controlled trial

A double-blinded randomised controlled trial of vitamin A drops to treat post-viral olfactory loss: study protocol for a proof-of-concept study for vitamin A nasal drops in post-viral olfactory loss (APOLLO)

BACKGROUND

Smell loss is a common problem with an estimated 5% of the population having no functioning sense of smell. Viral causes of smell loss are the second most common cause and the coronavirus (COVID-19) pandemic is estimated to have caused 20,000 more people this year to have a lasting loss of smell. Isolation, depression, anxiety, and risk of danger from hazards such as toxic gas and spoiled food are all negative impacts. It also affects appetite with weight loss/gain in two-thirds of those affected. Phantosmia or smell distortion can also occur making most foods seem unpalatable. Smell training has been tried with good results in the immediate post-viral phase. Evidence behind treatment with steroids has not shown to have proven effectiveness. With this, a key problem for patients and their clinicians is the lack of proven effective therapeutic treatment options. Based on previous studies, there is some evidence supporting the regenerative potential of retinoic acid, the metabolically active form of vitamin A in the regeneration of olfactory receptor neurons. It is based on this concept that we have chosen vitamin A as our study comparator.

AIM

To undertake a two-arm randomised trial of intranasally delivered vitamin A vs no intervention to determine proof of concept.

METHODS/DESIGN

The study will compare 10,000 IU once daily Vitamin A self-administered intranasal drops versus peanut oil drops (placebo) delivered over 12 weeks in patients with post-viral olfactory loss. Potentially eligible patients will be recruited from the Smell & Taste Clinic and via the charity Fifth Sense. They will be invited to attend the Brain Imaging Centre at the University of East Anglia on two occasions, 3 months apart. If they meet the eligibility criteria, they will be consented to enter the study and randomised to receive vitamin A drops or no treatment in a 2:1 ratio. MRI scanning will enable volumetric measurement of the OB and ROS; fMRI will then be conducted using an olfactometer to deliver pulsed odours-phenethylalcohol (rose-like) and hydrogen sulphide (rotten eggs). Participants will also perform a standard smell test at both visits as well as complete a quality-of-life questionnaire. Change in OB volume will be the primary outcome measure.

DISCUSSION

We expect the outputs of this study to enable a subsequent randomised controlled trial of Vitamin A versus placebo. With PPI input we will make the outputs publicly available using journals, conferences, and social media via Fifth Sense. We have already prepared a draft RCT proposal in partnership with the Norwich Clinical Trials Unit and plan to develop this further in light of the findings.

TRIAL REGISTRATION

ISRCTN registry 39523. Date of registration in the primary registry: 23rd February 2021.

Exploring Endotypes in Chronic Rhinosinusitis (ExpRess): Protocol for a cohort study

BACKGROUND

Chronic Rhinosinusitis (CRS) affects approximately 1 in 10 UK adults and impacts quality of life quality of life significantly. Response to treatment may be driven by individual CRS endotypes and therefore work to delineate biomarker clusters that may separate responders from non-responders is needed. The ongoing MACRO three-arm parallel-group trial randomises adult CRS patients to endoscopic sinus surgery, macrolide therapy or placebo.

AIM

This study aims to correlate CRS endotypes with clinical parameters from the ongoing MACRO trial, including olfactory function and outcomes in terms of response to treatment using core biomarkers sets.

METHODS

Adult CRS patients enrolled into the MACRO trial will be recruited from participating UK otorhinolaryngology departments. Nasal tissue samples and swabs will be obtained in theatre or clinic from patients randomised to all three trial arms. Nasal tissue will be analysed with multiplex electrochemiluminescence for 32 cytokines including IL-5, IL-13, IgE and periostin. Bacterial swabs will be analysed using illumina miSeq 16S amplicon sequencing. Mean expression for each biomarker will be reported for treatment responder and non-responder groups. Correlation of biomarkers with MACRO trial outcome data such as endoscopic evaluation scores and quality-of-life improvement scores will be reported.

DISCUSSION

Defining clear endotypes in CRS will contribute to refining patient pathways for the efficient use of clinical resources. This work may lay the groundwork for future studies to predict which patients might respond to medical or surgical therapy.

Observational retrospective study calculating health service costs of patients receiving surgery for chronic rhinosinusitis in England, using linked patient-level primary and secondary care electronic data

OBJECTIVES

Chronic rhinosinusitis (CRS) symptoms are experienced by an estimated 11% of UK adults, and symptoms have major impacts on quality of life. Data from UK and elsewhere suggest high economic burden of CRS, but detailed cost information and economic analyses regarding surgical pathway are lacking. This paper estimates healthcare costs for patients receiving surgery for CRS in England.

DESIGN

Observational retrospective study examining cost of healthcare of patients receiving CRS surgery.

SETTING

Linked electronic health records from the Clinical Practice Research Datalink, Hospital Episode Statistics and Office for National Statistics databases in England.

PARTICIPANTS

A phenotyping algorithm using medical ontology terms identified 'definite' CRS cases who received CRS surgery. Patients were registered with a general practice in England. Data covered the period 1997-2016. A cohort of 13 462 patients had received surgery for CRS, with 9056 (67%) having confirmed nasal polyps.

OUTCOME MEASURES

Information was extracted on numbers and types of primary care prescriptions and consultations, and inpatient and outpatient hospital investigations and procedures. Resource use was costed using published sources.

RESULTS

Total National Health Service costs in CRS surgery patients were £2173 over 1 year including surgery. Total costs per person-quarter were £1983 in the quarter containing surgery, mostly comprising surgical inpatient care costs (£1902), and around £60 per person-quarter in the 2 years before and after surgery, of which half were outpatient costs. Outpatient and primary care costs were low compared with the peak in inpatient costs at surgery. The highest outpatient expenditure was on CT scans, peaking in the quarter preceding surgery.

CONCLUSIONS

We present the first study of costs to the English healthcare system for patients receiving surgery for CRS. The total aggregate costs provide a further impetus for trials to evaluate the relative benefit of surgical intervention.

Endoscopic sinus surgery in adult patients with Chronic Rhinosinusitis with nasal polyps (PolypESS) - statistical analysis plan for a multicentre randomised controlled trial

Background: Chronic rhinosinusitis with nasal polyps (CRSwNP) afflicts 2-4% of the population and comes with a long time burden of disease and high societal costs. The current treatment consists of medical treatment alone or in combination with endoscopic sinus surgery. No consensus exists on the right timing and extent of disease that warrants surgery. Furthermore, there is lack of clinical knowledge about the benefit of surgery over medication only. The current study evaluates the clinical effectiveness and cost-effectiveness of endoscopic sinus surgery in addition to medical treatment versus medication alone in the adult patient group with nasal polyps (CRSwNP). Methods: The PolypESS trial is designed as a prospective, randomised, multicentre trial in adult patients with CRSwNP selected for primary or revision endoscopic sinus surgery by their otorhinolaryngologist. Patients are randomly assigned to endoscopic sinus surgery in addition to medication or medical therapy only. This paper details the statistical analysis plan (SAP) of this trial and was submitted before outcome data were available. Results: The primary outcome of the trial is disease-specific Health-Related Quality of Life quantified by the SNOT-22 at 12-months follow-up. Secondary outcomes consist of generic and disease-specific Health-Related Quality of Life, objective signs of disease and adverse events of treatment. Subgroup analyses will be performed to verify if treatment effects differ among patient phenotypes. Analyses will be completed according to this pre-specified SAP. The main analysis will be performed as a standard ITT analysis. Discussion: The PolypESS trial will show whether addition of endoscopic sinus surgery to medical treatment improves the disease-specific Health-Related Quality of Life quantified by the SNOT-22 at 12-months follow-up. Unforeseen deviations from the SAP at the time of analysis will be motivated and discussed in the final publication of the primary outcome of this study.

Maximising recruitment to a randomised controlled trial for chronic rhinosinusitis using qualitative research methods: the MACRO conversation study

Background

Randomised controlled trials (RCTs) are considered the ‘gold standard’ of medical evidence; however, recruitment can be challenging. The MACRO trial is a NIHR-funded RCT for chronic rhinosinusitis (CRS) addressing the challenge of comparing surgery, antibiotics and placebo. The embedded MACRO conversation study (MCS) used qualitative research techniques pioneered by the University of Bristol QuinteT team to explore recruitment issues during the pilot phase, to maximise recruitment in the main trial.

Methods

Setting: Five outpatient Ear Nose and Throat (ENT) departments recruiting for the pilot phase of the MACRO trial (ISRCTN Number: 36962030, prospectively registered 17 October 2018). We conducted a thematic analysis of telephone interviews with 18 recruiters and 19 patients and 61 audio-recordings of recruitment conversations. We reviewed screening and recruitment data and mapped patient pathways at participating sites. We presented preliminary findings to individual site teams. Group discussions enabled further exploration of issues, evolving strategies and potential solutions. Findings were reported back to the funder and used together with recruitment data to justify progression to the main trial.

Results

Recruitment in the MACRO pilot trial began slowly but accelerated in time to progress successfully to the main trial. Research nurse involvement was pivotal to successful recruitment. Engaging the wider network of clinical colleagues emerged as an important factor, ensuring the patient pathway through primary and secondary care did not inadvertently affect trial eligibility. The most common reason for patients declining participation was treatment preference. Good patient-clinician relationships engendered trust and supported patient decision-making. Overall, trial involvement appeared clearly presented by recruiters, possibly influenced by pre-trial training. The weakest area of understanding for patients appeared to be trial medications. A clear presentation of medical and surgical treatment options, together with checking patient understanding, had the potential to allay patient concerns.

Conclusion

The MACRO conversation study contributed to the learning process of optimising recruitment by helping to identify and address recruitment issues. Although some issues were trial-specific, others have applicability to many clinical trial situations. Using qualitative research techniques to identify/explore barriers and facilitators to recruitment may be valuable during the pilot phase of many RCTs including those with complex designs.

Prophylactic antibiotics after endoscopic sinus surgery for chronic rhinosinusitis: a randomized, double-blind, placebo-controlled noninferiority clinical trial

BACKGROUND

Surgeons commonly prescribe prophylactic antibiotics after endoscopic sinus surgery (ESS), yet minimal data exist to support this practice. In this study we aimed to assess the impact of post-ESS antibiotics on infection, quality of life (QOL), and endoscopic scores.

METHODS

This was a randomized, double-blind, placebo-controlled, noninferiority trial comparing amoxicillin-clavulanate vs placebo after ESS (NCT01919411, ClinicalTrials.gov). Adults (N = 77) with chronic rhinosinusitis (CRS) refractory to appropriate medical therapy who underwent ESS were randomized to antibiotics (N = 37) or placebo (N = 40) and followed clinically (mean ± standard deviation: 1.3 ± 0.3 and 8.8 ± 3.9 weeks postoperatively). At baseline and follow-up, QOL was measured with 22-item Sino-Nasal Outcome Test questionnaires and Lund-Kennedy endoscopic scores were evaluated. Outcomes were analyzed with repeated-measures analysis of variance and analysis of covariance and z tests for proportions.

RESULTS

Placebo was noninferior to antibiotic prophylaxis with regard to postoperative SNOT-22 scores (β = 0.18, 2-tailed p < 0.05). There were no significant differences between the antibiotic and placebo groups in LK score trajectories over time (p = 0.63) or in postoperative infection rates (2.6% vs 2.4%, respectively; p = 0.96). The rate of diarrhea was significantly higher in the antibiotic group (24.3% vs 2.5%; relative risk = 10.8; p = 0.02).

CONCLUSION

Although statistically underpowered, the results suggest placebo was noninferior to prophylactic antibiotics after ESS for CRS regarding postoperative sinonasal-specific QOL. There were no significant differences in postoperative endoscopic scores or rates of infection, but the rate of diarrhea was significantly higher in the antibiotic group. These findings add to the growing evidence that routine use of prophylactic postoperative antibiotics does not improve outcomes post-ESS and significantly increases the rate of diarrhea.

The Role of Macrolides and Doxycycline in Chronic Rhinosinusitis

Antibiotic therapy has become an important adjunct in the management of recalcitrant chronic rhinosinusitis (CRS) because of some antibiotics' immunomodulatory properties even at subtherapeutic antimicrobial levels. Macrolide antibiotics, such as clarithromycin and azithromycin, decrease production of proinflammatory cytokines, impair neutrophil recruitment, inhibit bacterial biofilm formation, and improve mucus quality. Doxycycline, a tetracycline antibiotic, inhibits the activity of matrix metalloproteinases in CRS with nasal polyposis. This article reviews the clinical applications for macrolide and doxycycline use in CRS, considerations for dosing and duration of treatment, and important side effects and drug interactions associated with these medications.

Practical help for specifying the target difference in sample size calculations for RCTs: the DELTA2 five-stage study, including a workshop

BACKGROUND

The randomised controlled trial is widely considered to be the gold standard study for comparing the effectiveness of health interventions. Central to its design is a calculation of the number of participants needed (the sample size) for the trial. The sample size is typically calculated by specifying the magnitude of the difference in the primary outcome between the intervention effects for the population of interest. This difference is called the 'target difference' and should be appropriate for the principal estimand of interest and determined by the primary aim of the study. The target difference between treatments should be considered realistic and/or important by one or more key stakeholder groups.

OBJECTIVE

The objective of the report is to provide practical help on the choice of target difference used in the sample size calculation for a randomised controlled trial for researchers and funder representatives.

METHODS

The Difference ELicitation in TriAls2 (DELTA2) recommendations and advice were developed through a five-stage process, which included two literature reviews of existing funder guidance and recent methodological literature; a Delphi process to engage with a wider group of stakeholders; a 2-day workshop; and finalising the core document.

RESULTS

Advice is provided for definitive trials (Phase III/IV studies). Methods for choosing the target difference are reviewed. To aid those new to the topic, and to encourage better practice, 10 recommendations are made regarding choosing the target difference and undertaking a sample size calculation. Recommended reporting items for trial proposal, protocols and results papers under the conventional approach are also provided. Case studies reflecting different trial designs and covering different conditions are provided. Alternative trial designs and methods for choosing the sample size are also briefly considered.

CONCLUSIONS

Choosing an appropriate sample size is crucial if a study is to inform clinical practice. The number of patients recruited into the trial needs to be sufficient to answer the objectives; however, the number should not be higher than necessary to avoid unnecessary burden on patients and wasting precious resources. The choice of the target difference is a key part of this process under the conventional approach to sample size calculations. This document provides advice and recommendations to improve practice and reporting regarding this aspect of trial design. Future work could extend the work to address other less common approaches to the sample size calculations, particularly in terms of appropriate reporting items.

FUNDING

Funded by the Medical Research Council (MRC) UK and the National Institute for Health Research as part of the MRC-National Institute for Health Research Methodology Research programme.

What is the most appropriate treatment for chronic rhinosinusitis?

Chronic rhinosinusitis (CRS) is a common, treatable disease that affects approximately 11% of British adults. It places an enormous burden on patients, with significant detriment to their quality of life, and the health service as it consumes vast numbers of both primary and secondary care resources. However, there is considerable variability in treatment strategies and prescribing practices. This review summarises the key recommendations from landmark guidelines in the treatment of CRS and critically appraises the evidence for treatment.