Full spectrum cannabidiol-rich extract reduced propofol dosage required for anesthetic induction in dogs-a pilot study

Introduction

Cannabinoids show great therapeutic potential, but their effect on anesthesia still remains unclear. Use of chronic recreational Cannabis in humans undergoing anesthetic procedures tends to require a higher dose when compared to non-users. On the other hand, studies on rodents and dogs have shown that cannabinoid agonists may potentiate certain anesthetics. This contrast of effects possibly occurs due to different time lengths of administration of different phytocannabinoids at different doses, and their distinct effects on the Endocannabinoid System, which is also affected by anesthetics such as propofol and isoflurane.

Methods

Twenty-seven healthy male dogs, client-owned, ranging from 1 to 7 years, and from 5 to 35 kg were selected, mean weight 15.03±7.39 kg, with owners volunteering their animals to participate in the research performed in the Federal University of Santa Catarina (UFSC). Dogs were randomized into 3 groups. The Control Group (CON, n = 9), receiving only Extra Virgin Olive Oil, the same oil-base used in the treatment groups. Group 2 (G2, n = 9) received 2 mg/kg of total phytocannabinoids, and Group 3 (G3, n = 9) received 6 mg/kg of total phytocannabinoids. All groups received their treatments transmucosally, 75 min before their induction with propofol. Heart and respiratory rate, blood pressure, temperature and sedation were evaluated prior to, and at 30, 60, and 75  min after administration of the fsCBD-rich extract or Placebo extract. Preanesthetic medication protocol was also included across all treatment groups, 15  min before induction. Parametric data was analyzed with one-way ANOVA, followed by Student-Newman-Keuls (SNK) if significant statistical differences were found. Non-parametric data was analyzed using Friedman's test, followed by Dunn test for comparisons between all timepoints in the same group. Kruskal-Wallis followed by Dunn was utilized for between groups comparisons. Propofol dose necessary for induction was analyzed through One-way ANOVA followed by Tukey's Multiple Comparisons Test, using Instat by Graphpad, and differences were considered statistically significant when p < 0.05. Our analysis assessed if statistical significance was present between time points in the same group, and between groups in the same time points.

Results

In our study, 6  mg/kg of total phytocannabinoids were able to reduce the dose of propofol necessary for induction by 23% when compared to the control group. The fsCBD-rich extract did not produce significant sedation within or between groups, although statistically significant differences in heart rate and systolic blood pressure were found.

Discussion

Our findings indicate that phytocannabinoids could be an adjunct option in anesthesia, although further research is necessary to better confirm this data. Additionally, further research is needed to determine the best dosage, delivery method, time for administration, ideal molecular profile for desired effects, safety, drug-drug interactions, and transurgical effects.

Does Melatonin Improve Sleep Following Primary Total Knee Arthroplasty? A Randomized, Double-Blind, Placebo-Controlled Trial

BACKGROUND

Sleep impairment following total knee arthroplasty (TKA) is common and may decrease patient satisfaction and recovery. Standardized postoperative recommendations for sleep disturbances have not been established. We aimed to assess whether melatonin use could promote healthy sleep and reduce sleep disturbance in the acute period following TKA.

METHODS

Patients undergoing primary, elective TKA between July 19, 2021 and January 4, 2024 were prospectively enrolled and randomized to receive either 5 mg of melatonin nightly or placebo for 14 days postoperatively. Participants recorded their nightly pain on the visual analog scale, the number of hours slept, and the number of night-time awakenings in a sleep diary starting the night of surgery (postoperative day [POD] 0). Sleep disturbance was assessed preoperatively and on POD 14 using the patient-reported outcome measurement information system sleep disturbance form. Epworth Sleepiness Scores were collected on POD 14 to assess sleep quality.

RESULTS

Of the 138 patients enrolled, 128 patients successfully completed the study protocol, with 64 patients in each group. Melatonin patients trended toward more hours of sleep on POD 2 (placebo: 5.0 ± 2.4, melatonin: 5.8 ± 2.0, P = .084), POD 3 (placebo: 5.6 ± 2.2, melatonin: 6.3 ± 2.0, P = .075), and averaged over POD 1 to 3 (placebo: 4.9 ± 2.0, melatonin: 5.6 ± 1.8, P = .073), although no differences were observed on POD 4 or after. Fewer night-time awakenings in the melatonin group were observed on POD 1 (placebo: 4.4 ± 3.9, melatonin: 3.6 ± 2.4, P = .197), although this was not statistically significant. Preoperative and postoperative Patient-Reported Outcomes Measurement Information System Sleep Disturbance score increases were comparable for both groups (placebo: 4.0 ± 8.4, melatonin: 4.6 ± 8.2, P = .894). The melatonin (65.4%) and placebo (65%) groups demonstrated similar rates of increased sleep disturbance.

CONCLUSIONS

Melatonin may promote longer sleep in the immediate postoperative period after TKA, although these benefits wane after POD 3. Disturbances in sleep should be expected for most patients, although melatonin may have an attenuating effect. Melatonin is safe and can be considered for TKA patients experiencing early sleep disturbances postoperatively.

Blinding Is Seeing: A Single-Centre Study Into the Viability of Auto-Injectors for Blinded-Drug Administration in Randomised Controlled Trials

Objective The aim of the study was to assess the viability of auto-injector systems (A-INJ) for preserving investigator blinding in randomized controlled trials (RCT). Background Blinding refers to the concealment of group allocation from one or more individuals involved in a clinical research study. In the dosing of subcutaneous (SC) and intramuscular (IM) investigational medicinal products (IMP), specific challenges arise in maintaining investigator blinding. These challenges primarily involve the active injectate's viscosity and visual appearance (colour/translucency) in comparison to the placebo. Existing methods to control these issues are not perfect. Common approaches include using unblinded investigators or applying films or additives to make the active and placebo injectates appear similar. Method A single-centre experimental and descriptive study was carried out to compare the use of an A-INJ (Owen Mumford, Autoject 2) with the use of a conventional syringe (CS) in delivering a 1 ml dose of both placebo and reference IMP. The percentage delivery of the injectate was compared between the A-INJ IMP and placebo groups. Additionally, eight trained research physicians serving as investigators recorded their assessments of safety and effectiveness after performing serial injections with the A-INJ into a human-tissue analogue. Results Overall, a mean of 95.38% of 1ml placebo injectate was released from the A-INJ, compared to 96.00% from the CS. A total of 94.715% of 1 ml IMP injectate was released from the A-INJ, as opposed to 94.74% from the CS. Independent t-test analyses showed no statistical significance between the experimental arms. The mean administration time was 8.5 seconds. Investigators were unable to differentiate between the two solutions when using the A-INJ. There were no recorded concerns about investigators becoming unblinded, which stands in contrast to concerns associated with using the CS. Conclusion In assessing the viability of A-INJ use in RCTs, we noted a marked improvement when blinding was used. A-INJ systems effectively administer both placebo and active injectates, thereby maintaining the benefit of blinding without the need to alter the placebo through the addition of colourants or viscosity additives. While audio cues from the A-INJ and the time required to administer the injectate pose challenges, solutions are suggested. Although our findings are preliminary, they add to the existing literature on the advantages of A-INJs for administering injectable compounds and offer new perspectives on their utility in RCTs.

Memantine for Refractory Obsessive-Compulsive Disorder: Protocol for a Pragmatic, Double-blind, Randomized, Parallel-Group, Placebo-Controlled, Monocenter Trial

BACKGROUND

Obsessive-compulsive disorder (OCD) is a psychiatric syndrome characterized by unwanted and repetitive thoughts and repeated ritualistic compulsions for decreasing distress. Symptoms can cause severe distress and functional impairment. OCD affects 2% to 3% of the population and is ranked within the 10 leading neuropsychiatric causes of disability. Cortico-striatal-thalamo-cortical circuitry dysfunction has been implicated in OCD, including altered brain activation and connectivity. Complex glutamatergic signaling dysregulation within cortico-striatal circuitry has been proposed in OCD. Data obtained by several studies indicate reduced glutamatergic concentrations in the anterior cingulate cortex, combined with overactive glutamatergic signaling in the striatum and orbitofrontal cortex. A growing number of randomized controlled trials have assessed the utility of different glutamate-modulating drugs as augmentation medications or monotherapies for OCD, including refractory OCD. However, there are relevant variations among studies in terms of patients' treatment resistance, comorbidity, age, and gender. At present, 4 randomized controlled trials are available on the efficacy of memantine as an augmentation medication for refractory OCD.

OBJECTIVE

Our study's main purpose is to conduct a double-blind, randomized, parallel-group, placebo-controlled, monocenter trial to assess the efficacy and safety of memantine as an augmentative agent to a selective serotonin reuptake inhibitor in the treatment of moderate to severe OCD. The study's second aim is to evaluate the effect of memantine on cognitive functions in patients with OCD. The third aim is to investigate if responses to memantine are modulated by variables such as gender, symptom subtypes, and the duration of untreated illness.

METHODS

Investigators intend to conduct a double-blind, randomized, parallel-group, placebo-controlled, monocenter trial to assess the efficacy and safety of memantine as an augmentative agent to a selective serotonin reuptake inhibitor in the treatment of patients affected by severe refractory OCD. Participants will be rated via the Yale-Brown Obsessive Compulsive Scale at baseline and at 2, 4, 6, 8, 10, and 12 months. During the screening period and T4 and T6 follow-up visits, all participants will undergo an extensive neuropsychological evaluation. The 52-week study duration will consist of 4 distinct periods, including memantine titration and follow-up periods.

RESULTS

Recruitment has not yet started. The study will be conducted from June 2023 to December 2024. Results are expected to be available in January 2025. Throughout the slow-titration period, we will observe the minimum effective dose of memantine, and the follow-up procedure will detail its residual efficacy after drug withdrawal.

CONCLUSIONS

The innovation of this research proposal is not limited to the evaluation of the efficacy and safety of memantine as an augmentation medication for OCD. We will also test if memantine acts as a pure antiobsessive medication or if memantine's ability to improve concentration and attention mimics an antiobsessive effect.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05015595; https://clinicaltrials.gov/ct2/show/NCT05015595.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

PRR1-10.2196/39223.

Efficacy of a 4-Antigen Staphylococcus aureus Vaccine in Spinal Surgery: The STRIVE Randomized Clinical Trial

BACKGROUND

Staphylococcus aureus is a global pathogen frequently responsible for healthcare-associated infections, including surgical site infections (SSIs). Current infection prevention and control approaches may be limited, with S aureus antibiotic resistance remaining problematic. Thus, a vaccine to prevent or reduce S aureus infection is critically needed. This study evaluated efficacy and safety of an investigational 4-antigen S aureus vaccine (SA4Ag) in adults undergoing elective open posterior spinal fusion procedures with multilevel instrumentation.

METHODS

In this multicenter, site-level, randomized, double-blind trial, subjects 18-85 years old received a single dose of SA4Ag or placebo 10-60 days before surgery. SA4Ag efficacy in preventing postoperative S aureus bloodstream infection and/or deep incisional or organ/space SSI was the primary endpoint. Safety evaluations included local reactions, systemic events, and adverse events (AEs). Immunogenicity and colonization were assessed.

RESULTS

Study enrollment was halted when a prespecified interim efficacy analysis met predefined futility criteria. SA4Ag showed no efficacy (0.0%) in preventing postoperative S aureus infection (14 cases in each group through postoperative Day 90), despite inducing robust functional immune responses to each antigen compared with placebo. Colonization rates across groups were similar through postoperative Day 180. Local reactions and systemic events were mostly mild or moderate in severity, with AEs reported at similar frequencies across groups.

CONCLUSIONS

In patients undergoing elective spinal fusion surgical procedures, SA4Ag was safe, well tolerated, but despite eliciting substantial antibody responses that blocked key S aureus virulence mechanisms, was not efficacious in preventing S aureus infection. ClinicalTrials.gov: NCT02388165.

Interferential therapy for chronic constipation in adults: The CON-COUR randomizedcontrolled trial

BACKGROUND

Chronic constipation (CC) is a frequent condition, and the first-line treatment includes dietary rules, the use of laxatives, and biofeedback for evacuation disorders. However, almost half of the patients are dissatisfied with their current treatment. We report the first double-blind randomized multicenter trial assessing the effectiveness of transabdominal electrical stimulation by interferential therapy (IFT) in the treatment of CC in adults.

METHODS

A prospective, multicenter, randomized, double-blind, sham-controlled, parallel-group, phase 3 trial was conducted at 7 centers in France. The primary endpoint was 8-week efficacy as defined by the number of complete spontaneous bowel movements during the last 4 weeks of the 8-week stimulation period. Secondary endpoints included the evaluation of the effects of IFT on symptoms (Patient Assessment of Constipation Symptoms questionnair (PAC-SYM)), quality of life (QOL) (Patient Assessment of Constipation Quality of Life), Colonic transit time (CTT), anorectal manometry, and patient satisfaction.

RESULTS

The proportion of 8-week responders was not significantly different between the two groups (73.2% in the IFT group vs. 67.1% in the sham group). After 8 weeks of stimulation, the mean overall PAC-SYM score and the mean reduction in the overall PAC-SYM score were significantly greater in the IFT group than in the sham group. No differences were observed concerning CTT, anorectal manometry, or patient satisfaction.

CONCLUSIONS

Although the primary endpoint was not reached, IFT can significantly alleviate the symptoms and improve the QOL of CC patients. It can be assumed that new treatments require different modes of evaluation and that the assessment of patient-reported outcomes may become a priority among therapeutic targets of CC. Trial registration number NCT02381665.

Treatment of acute exacerbations of chronic obstructive pulmonary disease with acupuncture during hospitalization: a three-arm double-blinded randomized sham-controlled trial

Background:

Acute exacerbations of chronic obstructive pulmonary disease (AECOPD) are a healthcare burden. Acupuncture improves dyspnea in patients with chronic obstructive pulmonary disease (COPD) but, to the best of our knowledge, has not been tested in AECOPD. Here, we evaluated the efficacy and safety of true acupuncture added to standard of care (SOC), as compared with both sham procedure plus SOC and SOC only, for the treatment of AECOPD among inpatients.

Methods:

This double-blinded randomized sham-controlled trial was set in a tertiary hospital in Israel. Patients with a clinical diagnosis of AECOPD were assigned to true acupuncture with SOC, sham procedure with SOC or SOC only. The primary outcome was dyspnea improvement as measured daily by the validated modified Borg (mBorg) scale. Secondary outcomes included improvement of other patient-reported outcomes and physiologic features, as well as duration of hospitalization and treatment failure. Acupuncture-related side effects were evaluated by the validated Acup-AE questionnaire.

Results:

Seventy-two patients were randomized: 26 to acupuncture treatment, 24 to sham and 22 to SOC only arms. Baseline characteristics were similar in the three groups. A statistically significant difference in dyspnea intensity was found from the first day of evaluation after treatment (p = 0.014) until day 3 after treatment. Similar results were found for sputum production, but no statistical significance was found when comparing physiologic features between the three arms. Acupuncture was not associated with adverse events.

Conclusion:

Acupuncture seems to be efficacious in the treatment of AECOPD among inpatients hospitalized in internal medicine departments.

Trial registration number:

NCT03398213 (ClinicalTrials.gov)

Repeated Transcranial Magnetic Stimulation for Improving Cognition in Alzheimer Disease: Protocol for an Interim Analysis of a Randomized Controlled Trial

BACKGROUND

Many clinical trials investigating treatment efficacy require an interim analysis. Recently we have been running a large, multisite, randomized, placebo-controlled, double-blind clinical trial investigating the effect of repetitive transcranial magnetic stimulation (rTMS) treatment for improving or stabilizing the cognition of patients diagnosed with Alzheimer disease.

OBJECTIVE

The objectives of this paper are to report on recruitment, adherence, and adverse events (AEs) to date, and to describe in detail the protocol for interim analysis of the clinical trial data. The protocol will investigate whether the trial is likely to reach its objectives if continued to the planned maximum sample size.

METHODS

The specific requirements of the analytic protocol are to (1) ensure the double-blind nature of the data while doing the analysis, (2) estimate the predictive probabilities of success (PPoSs), (3) estimate the numbers needed to treat, (4) re-estimate the initial required sample size. The initial estimate of sample size was 208. The interim analysis will be based on 150 patients who will be enrolled in the study and finish at least 8 weeks of the study. Our protocol for interim analysis, at the very first stage, is to determine the response rate for each participant to the treatment (either sham or active), while ensuring the double-blind nature of the data. The blinded data will be analyzed by a statistician to investigate the treatment efficacy. We will use Bayesian PPoS to predict the success rate and determine whether the study should continue.

RESULTS

The enrollment has been slowed significantly due to the COVID-19 pandemic and lockdown. Nevertheless, so far 133 participants have been enrolled, while 22 of these have been withdrawn or dropped out for various reasons. In general, rTMS has been found tolerable with no serious AE. Only 2 patients dropped out of the study due to their intolerability to rTMS pulses.

CONCLUSIONS

Overall, the study with the same protocol is going as expected with no serious AE or any major protocol deviation.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02908815; https://clinicaltrials.gov/ct2/show/NCT02908815.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/31183.

Repetitive transcranial magnetic stimulation for neuropathic pain: a randomized multicentre sham-controlled trial

Repetitive transcranial magnetic stimulation (rTMS) has been proposed to treat neuropathic pain but the quality of evidence remains low. We aimed to assess the efficacy and safety of neuronavigated rTMS to the motor cortex (M1) or dorsolateral prefrontal cortex (DLPFC) in neuropathic pain over 25 weeks. We did a randomised double-blind, placebo-controlled trial at four outpatient clinics in France. Patients aged 18-75 years with peripheral neuropathic pain were randomly assigned in a 1:1 ratio to M1 or DLPFC-rTMS and re-randomised in a 2:1 ratio to active or sham rTMS (10 Hz, 3000 pulses/session, 15 sessions over 22 weeks). Patients and investigators were blind to treatment allocation. The primary endpoint was the comparison between active M1-rTMS, active DLPCF-rTMS and sham-rTMS for the change over the course of 25 weeks (group by time interaction) in average pain intensity (from 0 no pain to 10 maximal pain) on the Brief Pain Inventory (BPI), using a mixed model repeated measures analysis in patients who received at least one rTMS session (modified ITT population). Secondary outcomes included other measures of pain intensity and relief, sensory and affective dimensions of pain, quality of pain, self reported pain intensity and fatigue (patients diary), patient and clinician global impression of change (PGIC, CGIC), quality of life, sleep, mood and catastrophizing. This study is registered with ClinicalTrials.gov NCT02010281. A total of 152 patients were randomised and 149 received treatment (49 for M1; 52 for DLPFC; 48 for sham). M1-rTMS reduced pain intensity versus sham-rTMS (estimate for group x session interaction: -0.048 ± 0.02; 95% CI: -0.09 to -0.01; p = 0.01). DLPFC-rTMS was not better than sham (estimate: -0.003 ± 0.01; 95% CI:-0.04 to 0.03, p = 0.9). M1-rRMS, but not DLPFC-rTMS, was also superior to sham-rTMS on pain relief, sensory dimenson of pain, self reported pain intensity and fatigue, PGIC and CGIC. There were no effect on quality of pain, mood, sleep and quality of life as all groups improved similarly over time. Headache was the most common side effect and occurred in 17 (34.7%), 23 (44.2%) and 13 (27.1%) patients from M1, DLPFC and sham groups respectively (p = 0.2). Our results support the clinical relevance of M1-rTMS, but not of DLPFC-rTMS, for peripheral neuropathic pain with an excellent safety profile.

A randomized, double-blind, placebo-controlled phase III clinical trial to evaluate the efficacy and safety of SARS-CoV-2 vaccine (inactivated, Vero cell): a structured summary of a study protocol for a randomised controlled trial

Objectives

The primary objective is to evaluate the efficacy of an inactivated and aluminium hydroxide adsorbed SARS-CoV-2 vaccine (Sinovac, China) in voluntary participants after 14 days of the second dose against RT-PCR confirmed symptomatic COVID-19 cases. The secondary objectives include evaluating the efficacy after at least one dose of the vaccine against RT-PCR confirmed symptomatic COVID-19 cases; the efficacy of two doses of the vaccine on the rates of hospitalization and death; the safety of the vaccine including adverse reactions up to one year after the 2^nd dose of vaccination; and the immunogenicity of the vaccine and its duration up to 120 days.

Trial Design

This is a phase III, randomized, double-blind, placebo-controlled case driven clinical trial to assess the efficacy and safety of the vaccine. The study is planned to be carried out within two separate cohorts in voluntary participants aged between 18-59 years old. The first cohort includes healthcare professionals actively working in healthcare units, who are assumed to have higher risk of acquiring COVID-19, and the second cohort includes other immunocompetent subjects in the same age group, who are at a regular risk for COVID-19 disease. In Cohort 1, healthcare professionals will be randomized to receive two intramuscular doses of investigational product or the placebo in a 1:1 ratio and they will be monitored for 12 months by active surveillance of COVID-19. In Cohort 2, immunocompetent subjects will be randomized to receive vaccine or the placebo in a 2:1 ratio.

Participants

Healthcare professionals of both genders, including medical doctors, nurses, cleaners, hospital technicians, and administrative personnel who work in any department of a healthcare unit and immunocompetent individuals of both genders are included. Pregnant (confirmed by positive beta-hCG test) and breastfeeding women as well as those intending to become pregnant within three months after vaccination are excluded. Other exclusion criteria include history of COVID-19 test positivity (PCR or immunoglobulin test results), any form of immunosuppressive therapy including corticosteroids within 6 months, history of bleeding disorders, asplenia, and administration of any form of immunoglobulins or blood products within 3 months.

Exclusion criteria for the second dose include any serious adverse events related with the vaccine, anaphylaxis or hypersensitivity after vaccination, or any confirmed or suspected autoimmune or immunosuppressive disease (including HIV infection).

Participants are only included after signing the voluntary informed consent form, ensuring cooperation in visits, undergoing screening for evaluation, and conforming to all the inclusion and exclusion criteria. All clinical sites are located in Turkey.

Intervention and comparator

The vaccine was manufactured by Sinovac Research & Development Co., Ltd. It is a preparation made from a novel coronavirus (strain CZ02) grown in the kidney cell cultures (Vero Cell) of the African green monkey and contains inactivated SARS-CoV-2 virus, aluminium hydroxide, disodium hydrogen phosphate, sodium dihydrogen phosphate, and sodium chloride. A dose of 0.5 mL contains 600 SU of SARS-CoV-2 virus antigen. The placebo contains aluminium hydroxide, disodium hydrogen phosphate, sodium dihydrogen phosphate, and sodium chloride (0.5mL/dose).

Scheduled visits and additional unscheduled weekly visits will be performed for the first 13 weeks and neutralizing antibody test, IgG test, T-Cell activation test, pregnancy test, and RT-PCR tests along with total antibody test will be performed. Adverse events and serious adverse events during the follow-up will be recorded on diary cards. Diary cards will collect information on the timing and severity of COVID-19 symptoms and solicited adverse events recorded by the subjects during one-year follow-up period. All serious adverse events will be managed and necessary treatment will be ensured according to the local regulations. All serious adverse events following vaccination will be reported to the ethics committee, the Ministry of Health, and the study sponsor within 24 hours of detection.

Main Outcomes

The primary efficacy endpoint is the incidence of symptomatic cases of COVID-19 disease confirmed by RT-PCR two weeks after the second dose of vaccination. Secondary efficacy endpoints are the incidence of hospitalization/mortality rates among one or two dose regimens, duration of immunogenicity rates up to 120 days, the seroconversion rate, the seropositivity rate, neutralizing antibody titer, and IgG levels 14 days after each dose of vaccination. The primary safety endpoint is the severity and frequency of local and systemic adverse reactions during the period of one week after vaccination. The study would be terminated if more than 15% of the subjects have grade ≥3 adverse events related to vaccination including local reactions.

Randomisation

Eligible subjects will be randomized at their Study Day 0 to two study groups using an Interactive Web Response System (IWRS; developed by Omega CRO, Ankara, Turkey) in both risk groups. The IWRS system customizes the randomization algorithm. After enrolment in the study, each participant will be randomly assigned to either of the two treatment arms at a ratio of 1:1 in the high-risk group and at a ratio of 2:1 in the normal risk group. Each enrolled participant will be assigned to a code and will receive the treatment labelled with the code.

Blinding (masking)

The trial is a double-blind study to avoid introducing bias. The blinding may be broken by the investigator in the event of a medical emergency in which knowledge of the identity of the study vaccine is critical for management of the subject’s immediate treatment. The Data and Safety Monitoring Board is to be contacted in case of breaking the blinding for a study object. The blood samples will be taken from both placebo and vaccinated groups, in order not to break the blinding.

Numbers to be randomised (sample size)

The study is planned to be carried out with two separate cohorts. The Cohort 1 includes healthcare professionals working in healthcare units and the Cohort 2 consists of immunocompetent subjects having normal risk for COVID-19 disease. The Cohort 2 will be initiated after the evaluation of the interim safety report of the Cohort 1 by the Data and Safety Monitoring Board. Both cohorts will be followed-up via RT-PCR to confirm symptomatic COVID-19 cases. If the clinical efficacy of the vaccine is shown in the Cohort 1 or 2, the subjects randomized into the placebo arm will also be vaccinated. In the Cohort 1, 588 subjects should be included in both arms with the assumption that the risk of infection with COVID-19 will be 5% for the placebo arm and 2% for the vaccine arm in the high-risk group. Considering 10% of drop-out rate and 5% of seropositivity or PCR positivity at baseline, 680 subjects should be screened at both arms of the Cohort 1. Group sample sizes of 7545 SARS-CoV-2 vaccine and 3773 placebo suits at a two-sided 95% confidence interval for the difference in population proportions with a width equal to 1.0%, when the estimated incidence rate for vaccinated group is 1.0% and the estimated incidence rate for placebo group is 2.0%. Drop-out rate is assumed to be 10% and seropositivity or PCR positivity at baseline is assumed to be 5%; accordingly, 13000 participants are needed to be enrolled totally in both cohorts. The remaining 11640 subjects will be screened in the Cohort 2 and eligible subjects will be randomized at a ratio of 2:1.

Trial Status

Protocol version 6.0 – 15 October 2020. Recruitment started on 15.09.2020 and is expected to end on February 2022.

Trial Registration

ClinicalTrials.gov, NCT04582344. Registered 8 October 2020

Full Protocol

The full protocol of the trial is attached as an additional file, accessible from the Trials website (Additional file 1). In the interest in expediting dissemination of this material, the familiar formatting has been eliminated; this Letter serves as a summary of the key elements of the full protocol.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-021-05180-1.

Network meta-analysis of efficacy and safety of chlorthalidone and hydrochlorothiazide in hypertensive patients

Hypertension is a chronic condition leading to increased stress on the heart and blood vessels, a critical risk factor for clinically significant events such as myocardial infarction heart failure, stroke and death. Chlorthalidone and hydrochlorothiazide are first-line antihypertensive agents for most patients with hypertension. The aim of our meta-analysis was to compare the efficacy and safety of both therapies in patients with hypertension. Searches of electronic databases PubMed, MEDLINE, Scopus, PsycInfo and eLIBRARY.ru, were performed. We used network meta-analysis to combine direct and indirect evidence. Forest plots and closed loops depict estimated results from studies included in our meta-analysis. Of 1289 identified sources, only 37 were included in our meta-analysis. Our analysis has demonstrated a slight superiority for chlorthalidone regarding SBP and not statistically significant differences regarding DBP. Simultaneously, hydrochlorothiazide seems to be a safer choice of therapy, as evidenced by the levels of serum potassium. The two diuretics can be used interchangeably.

Repeated Transcranial Magnetic Stimulation for Improving Cognition in Patients With Alzheimer Disease: Protocol for a Randomized, Double-Blind, Placebo-Controlled Trial

Background

Alzheimer disease has no known cure. As existing pharmacologic interventions only modestly slow cognitive decline, there is a need for new treatments. Recent trials of repetitive transcranial magnetic stimulation (rTMS) have reported encouraging results for improving or stabilizing cognition in patients diagnosed with Alzheimer dementia. However, owing to small samples and lack of a well-controlled double-blind design, the results to date are inconclusive. This paper presents the protocol for a large placebo-controlled double-blind study designed with sufficient statistical rigor to measure the efficacy of rTMS treatment in patients with Alzheimer dementia.

Objective

The objectives are to (1) recruit and enroll up to 200 eligible participants, (2) estimate the difference in treatment effects between active treatment and sham treatment, (3) estimate the difference in treatment effects between two doses of rTMS applications, (4) estimate the duration of treatment effects among responders to active rTMS treatment, and (5) estimate the effect of dementia severity on treatment outcomes among patients receiving active rTMS treatment.

Methods

We have designed our study to be a double-blind, randomized, placebo-controlled clinical trial investigating the short- and long-term (up to 6 months) benefits of active rTMS treatment at two doses (10 sessions over 2 weeks and 20 sessions over 4 weeks) compared with sham rTMS treatment. The study will include patients aged ≥55 years who are diagnosed with Alzheimer disease at an early to moderate stage and have no history of seizures and no major depression. The primary outcome measure is the change in the Alzheimer Disease Assessment Scale-Cognitive Subscale score from pretreatment to posttreatment. Secondary outcomes are changes in performance on tests of frontal lobe functioning (Stroop test and verbal fluency), changes in neuropsychiatric symptoms (Neuropsychiatric Inventory Questionnaire), and changes in activities of daily living (Alzheimer Disease Co-operative Study-Activities of Daily Living Inventory). Tolerability of the intervention will be assessed using a modification of the Treatment Satisfaction Questionnaire for Medication. We assess participants at baseline and 3, 5, 8, 16, and 24 weeks after the intervention.

Results

As of November 1, 2020, we have screened 523 individuals, out of which 133 were eligible and have been enrolled. Out of the 133 individuals, 104 have completed the study. Moreover, as of November 1, 2020, there has been no serious adverse event. We anticipate that rTMS will considerably improve cognitive function, with effects lasting up to 3 months. Moreover, we expect rTMS to be a well-tolerated treatment with no serious side effect.

Conclusions

This protocol design will allow to address both the rTMS active treatment dose and its short- and long-term effects compared with sham treatment in large samples.

Trial Registration

ClinicalTrials.gov NCT02908815; https://clinicaltrials.gov/ct2/show/NCT02908815

International Registered Report Identifier (IRRID)

DERR1-10.2196/25144

Efficacy of Ethanolic Extract of Opuntia ficus-indica var. saboten Stems for Improving Cognitive Function in Elderly Subjects 55-85 Years of Age: A Randomized, Double-Blind, Placebo-Controlled Study

Many natural compounds have been reported to improve cognitive function in cell- and animal-based studies. In this clinical trial, we evaluated the efficacy of ethanolic extract of Opuntia ficus-indica var. saboten stem for improving cognitive function using a randomized, double-blind, placebo-controlled trial (n = 81) in aged people. After 12 weeks of administration of OFE (a mixture of ethanolic extract of O. ficus-indica var. Saboten stem and dextrin) or placebo, the effect on cognitive function was assessed. Overall, OFE did not show a significant difference from the placebo in terms of efficacy. However, the cognitive function significantly improved in the OFE group compared with the placebo group in the subgroup ≤70 years of age, which means that the effect of OFE administration exhibits an age-dependent effect. In addition, the safety of OFE was confirmed by analyzing blood test results, vital signs, and electrocardiograms. In conclusion, OFE administration in participants ≤70 years of age shows a positive effect on overall cognitive function. The trial was registered on CRIS (the Clinical Research Information Service), administered by the Korea Centers for Disease Control & Prevention (Registration Number: KCT0003766; URL: https://cris.nih.go.kr/cris/en/search/search_result_st01.jsp?seq=12957).

Hydralazine vs nifedipine for acute hypertensive emergency in pregnancy: a randomized controlled trial

BACKGROUND

There is a paucity of good quality evidence regarding the best therapeutic option for acute control of blood pressure during acute hypertensive emergency of pregnancy.

OBJECTIVE

We sought to compare the efficacy of intravenously administered hydralazine and oral nifedipine for acute blood pressure control in acute hypertensive emergency of pregnancy.

STUDY DESIGN

In this double-blind, randomized, controlled trial, pregnant women (≥24 weeks period of gestation) with sustained increase in systolic blood pressure of ≥160 mm Hg or diastolic blood pressure of ≥110 mm Hg were randomized to receive intravenous hydralazine injection in doses of 5, 10, 10, and 10 mg and a placebo tablet or oral nifedipine (10 mg tablet up to 4 doses) and intravenous saline injection every 20 minutes until the target blood pressure of 150 mm Hg systolic and ≤100 mm Hg diastolic was achieved. Crossover treatment was administered if the initial treatment failed. The primary outcome of the study was time necessary to achieve target blood pressure. The secondary outcomes were the number of dosages required, adverse maternal and neonatal effects, and perinatal outcome.

RESULTS

From December 2014 through September 2015, we enrolled 60 patients. The median time to achieve target blood pressure was 40 minutes in both groups (intravenous hydralazine and oral nifedipine) (interquartile interval 5 and 40 minutes, respectively, P = .809). The median dose requirement in both groups was 2 (intravenous hydralazine and oral nifedipine) (interquartile range 1 and 2 doses, respectively, P = .625). Intravenous hydralazine was associated with statistically significantly higher occurrence of vomiting (9/30 vs 2/30, respectively, P = .042). No serious adverse maternal or perinatal side effects were witnessed in either group.

CONCLUSION

Both intravenous hydralazine and oral nifedipine are equally effective in lowering of blood pressure in acute hypertensive emergency of pregnancy.

A combined study of MEG and pico-Tesla TMS on children with autism disorder

Magnetoencephalographic (MEG) recordings from the brain of 10 children with autism (6 boys and 4 girls, with ages range from 5-12 years, mean[Formula: see text][Formula: see text][Formula: see text]SD: 8.3[Formula: see text][Formula: see text][Formula: see text]2.1) were obtained using a whole-head 122-channel MEG system in a magnetically shielded room of low magnetic noise. A double-blind experimental design was used in order to look for possible effect of external pico-Tesla Transcranial Magnetic Stimulation (pT-TMS). The pT-TMS was applied on the brain of the autistic children with proper field characteristics (magnetic field amplitude: 1-7.5[Formula: see text]pT, frequency: the alpha - rhythm of the patient 8-13[Formula: see text]Hz). After unblinding it was found a significant effect of an increase of frequencies in the range of 2-7[Formula: see text]Hz across the subjects followed by an improvement and normalization of their MEG recordings. The statistical analysis of our results showed a statistical significance at 6 out of 10 patients (60%). It is also observed an increase of alpha activity in autistic children at the end of one month after pT-TMS treatment at home. In conclusion, the application of pT-TMS has the prospective to be a noninvasive, safe and important modality in the management of autism children.

Effect of steroids for nasal polyposis surgery: A placebo-controlled, randomized, double-blind study

OBJECTIVES/HYPOTHESIS

Although medical intervention is the first option for treatment of nasal polyps, surgery is still a therapeutic option for symptomatic cases that do not respond or partially respond to medical intervention. However, there is a need for high-level evidence for the preoperative use of steroids in nasal polyposis surgery. We aimed to assess the perioperative effect of preoperative use of oral prednisolone for advanced-stage diffuse nasal polyposis.

STUDY DESIGN

Prospective, double-blind, randomized, placebo-controlled study.

METHODS

A visual analog scale (VAS) was evaluated for smell, nasal discharge, nasal obstruction, facial pressure, headache, butanol smell threshold, and peak nasal inspiratory flow (PNIF) before and after the use of study drug. Perioperative bleeding volume, visibility of operative field, operative time, hospital stay, and complication rate were also evaluated.

RESULTS

The improvement in the corticosteroid group (CG) in the VAS scores, butanol thresholds, and PNIF values showed statistically significant differences compared to the placebo group (PG) (P < .05). The perioperative bleeding volume, visibility score, operative time, and hospital stay for CG/PG were 141 mL/384 mL, 2.4/3.4, 61 min/71.6 min, and 1.1 day/1.8 day, respectively (P < .05). The difference between the complication rates for the two groups did not show any statistically significant difference (P = .214).

CONCLUSIONS

Preoperative administration of systemic corticosteroids improves the perioperative visibility by reducing blood loss and shortens the operation time. We recommend the use of preoperative corticosteroid for the safety of the patients. The optimum dose and duration have not been established and require further studies.

LEVEL OF EVIDENCE

1b.

The Potential of Double Blinding with Two Placebo Acupuncture Needles: A Randomized Controlled Pilot-Trial

Background: Whether acupuncture treatment employing multiple penetrating, skin-touch placebo, or no-touch placebo needles designed for double blinding actually do blind practitioners and patients has not been investigated. We aimed to investigate this question. Subjects: 120 patients with functional neck/shoulder stiffness but in otherwise healthy condition were randomly assigned to a treatment using four penetrating, four skin-touch placebo, or four no-touch placebo needles. Each of six acupuncturists applied four needles to four acupoints in the neck/shoulder of 20 patients. Acupuncturists and patients were asked to guess the treatment mode and their confidence in their guesses on 100 mm visual analog scales. Results: The kappa coefficients between practitioner guesses and treatment type and between patient guesses and treatment type were 0.15 and 0.44, respectively. The median score of practitioner confidence was 46.8, and no significant difference in confidence between correct and incorrect guesses was revealed for any treatment. The median score of patient confidence for correct guesses was 77.6. The kappa coefficient between practitioner and patient guesses was 0.06. Conclusions: The practitioners were blinded to the nature of treatment using the same multiple needles, but patient blinding was insufficient. Further improvement is necessary to achieve satisfactory patient blinding with these acupuncture needles.

Do randomized clinical trials with inadequate blinding report enhanced placebo effects for intervention groups and nocebo effects for placebo groups?

BACKGROUND

Studies suggest that expectations powerfully shape clinical outcomes. For subjective outcomes in adequately blinded trials, health improvements are substantial and largely explained by non-specific factors.The objective of this study was to investigate if unblinding in randomized controlled trials (RCTs) is associated with enhanced placebo effects for intervention groups and nocebo effects for placebo groups. For these effects, a secondary objective was to explore potential moderating factors.

METHODS

We included RCTs that investigated the efficacy of phosphodiesterase-5 (PDE-5) inhibitors for male erectile dysfunction by comparing one PDE-5 inhibitor to placebo. In addition, to be included studies must have reported scores for change from baseline, or baseline and final International Index of Erectile Functioning-Erectile Functioning domain score (IIEF-EF), and be published in either English, French, Dutch, or German.We searched for both published and unpublished relevant trials using PUBMED, EMBASE, the Cochrane Central Register of Controlled Trials, a clinical trials register (clinicaltrials.gov) and the Food and Drug Administration clinical reviews through March 2012.We evaluated the blinding status of trials with the Cochrane Risk of Bias Tool, using the domains of allocation sequence concealment, blinding of participants, healthcare providers and outcome assessors. Across these four domains, studies that scored low risk of bias were judged to be adequately blinded and studies that scored unclear or high risk of bias were judged to be inadequately blinded.

RESULTS

We included 110 studies (205 journal publications and 2 unpublished sources) that involved 23,877 participants; 93 (85%), 51 (46%), 93 (85%) and 93 (85%) studies were assessed with an unclear risk of bias for allocation concealment, blinding of participant, blinding of caregiver and blinding of outcome assessor, respectively. None of the studies reported testing of blinding.None of the 205 journal publications provided sufficient details to assess allocation concealment, blinding of participants, caregivers and outcome assessors. After contacting authors for additional information, we judged five studies to be adequately (n = 1,202) and 16 to be inadequately (n = 3,006) blinded. The IIEF-EF score for placebo groups in adequately blinded trials versus inadequately blinded trials was 1.92 points (95% CI, 0.64 to 3.20) versus 1.56 (95% CI, 0.93 to 2.20), respectively. The IIEF-EF score for intervention groups in adequately blinded trials versus inadequately blinded trials was 9.40 (95% CI, 6.96 to 11.83) versus 8.33 (95% CI, 7.29 to 9.37), respectively. In a secondary analysis, prior experience with the drug affected the scores; in placebo groups with participants naïve to the intervention the score was 2.89 (95% CI, 2.33 to 3.45) versus -0.11 (95% CI, -2.06 to 1.84) with participants having prior experience. In the intervention groups, these scores were 7.99 (95% CI, 6.85 to 9.14) versus 8.33 (95% CI, 7.51 to 9.16), respectively.Unblinding lowered placebo scores (creating a nocebo effect) by 19% (0.33 points; 95% CI, -0.96 to 1.62). Unblinding lowered intervention scores by 11% (1.0; 95% CI, -1.35 to 3.47). The results provided no conclusive evidence for nocebo or enhanced placebo effects. Patients taking a PDE-5 inhibitor for the first time experience a larger placebo effect that accounts for 35% of the total effect.

CONCLUSIONS

Given the overall poor reporting of blinding in clinical trial reports and the small number of trials that could be rated as adequately or inadequately blinded, we could not draw any robust conclusions about the existence or absence of nocebo and enhanced placebo effects. A large placebo effect was found for patients taking PDE-5 inhibitors for the first time. It was not clear if previous exposure to the drug impacted trial blinding.We found clear evidence that studies assessing a subjective continuous outcome fail to report on measures taken to secure double blinding. Although we observed a trend for the presence of a nocebo effect, there was insufficient evidence to quantify its impact on expectations. RCTs with patients with no prior experience with PDE-5 inhibitors reported larger placebo effects and possibly these studies were better blinded. Future research should further investigate the factors that contribute to blinding and their impact on health outcomes in randomized trials of subjectively assessed conditions. This research is part of a PhD project and has no external funding. The authors have no competing interests to declare.

VSL#3 ® probiotic therapy does not reduce portal pressures in patients with decompensated cirrhosis

BACKGROUND & AIMS

In patients with decompensated cirrhosis, bacterial translocation can contribute to splanchnic vasodilatation, decreased effective circulating volume, and portal hypertension. The primary objective of this randomized, double blind placebo controlled trial was to evaluate the effect of the probiotic VSL#3(®) on the hepatic venous pressure gradient (HVPG).

METHODS

Seventeen patients with decompensated cirrhosis and an HVPG of ≥ 10 mmHg were randomized to receive 2 months of VSL#3(®) or an identical placebo. HVPG, endotoxin, interleukin (IL)-6, IL-8, IL-10, renin, aldosterone, nitric oxide and stool microbiota were measured at baseline and study end.

RESULTS

Two of the 17 patients were taken off the trial before completion (one for alcohol abuse and the second for SBP - both in placebo arm). Data were analysed on the remaining 15 patients. The median model for end-stage liver disease score was 12, and 80% of patients had Child Pugh B disease. The treatment arm had a greater decrease in HVPG from baseline to study end than the placebo arm (median change from baseline -11.6% vs +2.8%), although this reduction was not statistically significant in either group. There was a significant reduction in the plasma aldosterone level in the VSL#3(®) group, but no significant changes in the other measured parameters, including the stool microflora analysis.

CONCLUSIONS

Within the limitations of our sample size, VSL#3(®) therapy does not appear to have a significant impact on portal pressure reduction in patients with decompensated cirrhosis.

Analgesic efficacy of high-frequency spinal cord stimulation: a randomized double-blind placebo-controlled study

INTRODUCTION

Spinal cord stimulation is a recognized treatment of chronic neuropathic and vascular pain. Recent data suggest that the use of very high-frequency (HF) stimulation modes does produce analgesia without paresthesia.

AIM OF THE STUDY

To compare the efficacy of HF stimulation (HF spinal cord stimulation [HFSCS]) and sham stimulation on the patient's global impression of change (PGIC), pain intensity, and quality of life.

PATIENTS AND METHODS

Forty patients who have achieved stable pain relief with conventional SCS have been recruited. After randomization, HFSCS and sham are initiated in a double-blind randomized two-period-crossover design.

RESULTS

Complete data were available from 33 patients. The primary outcome was a minimal improvement in the PGIC. The proportion of patients responding under HFSCS was 42.4% (14/33 patients) vs. 30.3% (10/33 patients) in the sham condition. The mean benefit of HF vs. sham was not statistically significant with a proportion of 11.2% in favor of HFSCS (p = 0.30). There was a highly statistically significant "period effect," irrespective of treatment received, with 51.5% of patients (N = 17) improving at visit 3 vs. 21.2% (N = 7) at visit 5 (p = 0.006). The mean pain visual analog scale (VAS) on sham was 4.26 vs. 4.35 on HFSCS (p = 0.82) and the mean EuroQol five-dimensional (EQ-5D) index with HFSCS was 0.480 vs. 0.463 with sham (p = 0.78).

CONCLUSION

This is the first randomized double-blind study on SCS. HFSCS was equivalent to sham for the primary outcome (improvement of PGIC) as well as for both the secondary outcomes (VAS and EQ-5D index). There was a highly statistically significant "period effect" (p = 0.006) with improved PGIC scores in the first study period regardless of the treatment. The same trend was seen for VAS and EQ-5D. It appears that the effect of HFSCS and sham is equal and only the order in the sequence, not the nature of the treatment, seems to dictate the effect.

Over-, under- and misuse of pain treatment in Germany

BACKGROUND

The HTA-report (Health Technology Assessment) deals with over- and undertreatment of pain therapy. Especially in Germany chronic pain is a common reason for the loss of working hours and early retirement. In addition to a reduction in quality of life for the affected persons, chronic pain is therefore also an enormous economic burden for society.

OBJECTIVES

Which diseases are in particular relevant regarding pain therapy?What is the social-medical care situation regarding pain facilities in Germany?What is the social-medical care situation in pain therapy when comparing on international level?Which effects, costs or cost-effects can be seen on the micro-, meso- and macro level with regard to pain therapy?Among which social-medical services in pain therapy is there is an over- or undertreatment with regard to the micro-, meso- and macro level?Which medical and organisational aspects that have an effect on the costs and/or cost-effectiveness have to be particularly taken into account with regard to pain treatment/chronic pain?What is the influence of the individual patient's needs (micro level) in different situations of pain (e. g. palliative situation) on the meso- and macro level?Which social-medical and ethical aspects for an adequate treatment of chronic pain on each level have to be specially taken into account?Is the consideration of these aspects appropriate to avoid over- or undertreatment?Are juridical questions included in every day care of chronic pain patients, mainly in palliative care?On which level can appropriate interventions prevent over- or undertreatment?

METHODS

A systematic literature research is done in 35 databases. In the HTA, reviews, epidemiological and clinical studies and economic evaluations are included which report about pain therapy and in particular palliative care in the years 2005 till 2010.

RESULTS

47 studies meet the inclusion criteria. An undertreatment of acupuncture, over- and misuse with regard to opiate prescription and an overuse regarding unspecific chest pain and chronic low back pain (LBP) can be observed. The results show the benefit and the cost-effectiveness of interdisciplinary as well as multi-professional approaches, multimodal pain therapy and cross-sectoral integrated medical care. Only rough values can be determined about the care situation regarding the supply of pain therapeutic and palliative medical facilities as the data are completely insufficient.

DISCUSSION

Due to the broad research question the HTA-report contains inevitably different outcomes and study designs which partially differ qualitatively very strong from each other. In the field of palliative care hospices for in-patients and palliative wards as well as hospices for out-patients are becoming more and more important. Palliative care is a basic right of all terminally ill persons.

CONCLUSION

Despite the relatively high number of studies in Germany the HTA-report shows a massive lack in health care research. Based on the studies a further expansion of out-patient pain and palliative care is recommended. Further training for all involved professional groups must be improved. An independent empirical analysis is necessary to determine over or undertreatment in pain care.

Informative value of Patient Reported Outcomes (PRO) in Health Technology Assessment (HTA)

Background

“Patient-Reported Outcome” (PRO) is used as an umbrella term for different concepts for measuring subjectively perceived health status e. g. as treatment effects. Their common characteristic is, that the appraisal of the health status is reported by the patient himself. In order to describe the informative value of PRO in Health Technology Assessment (HTA) first an overview of concepts, classifications and methods of measurement is given. The overview is complemented by an empirical analysis of clinical trials and HTA-reports on rheumatoid arthritis and breast cancer in order to report on type, frequency and consequences of PRO used in these documents.

Methods

For both issues systematic reviews of the literature have been performed. The search for methodological literature covers the publication period from 1990 to 2009, the search for clinical trials of rheumatoid arthritis and breast cancer covers the period 2005 to 2009. Both searches were performed in the medical databases of the German Institute of Medical Documentation and Information (DIMDI). The search for HTA-reports and methodological papers of HTA-agencies was performed in the CRD-Databases (CRD = Centre for Reviews and Dissemination) and by handsearching the websites of INAHTA member agencies (INAHTA = International Network of Agencies for Health Technology Assessment). For all issues specific inclusion and exclusion criteria were defined. The methodological quality of randomized controlled trials (RCT) was assessed by a modified version of the Cochrane Risk of Bias Tool. For the methodological part information extraction from the literature is structured by the report’s chapters, for the empirical part data extraction sheets were constructed. All information is summarized in a qualitative manner.

Results

Concerning the methodological issues the literature search retrieved 158 documents (87 documents related to definition or classification, 125 documents related to operationalisation of PRO). For the empirical analyses 225 RCT (rheumatoid arthritis: 77; breast cancer: 148) and 40 HTA-reports and method papers were found.

The analysis of the methodological literature confirms the role of PRO as an umbrella term for a variety of different concepts. The newest classification system facilitates the description of PRO measures by construct, target population and the method of measurement. Steps of operationalisation involve defining a conceptual framework, instrument development, exploration of measurement properties or, possibly, the modification of existing instruments.

Seven out of 59 RCT analysing the effects of antibody therapy for rheumatoid arthritis define PRO as the primary endpoint, 38 trials utilize composite measures (ACR, DAS) and ten trials report clinical or radiological parameters as the primary endpoint. Six out of 123 chemotherapy trials for breast cancer define PRO as the primary endpoint, while 98 trials report clinical endpoints (survival, tumour response, progression) in their primary analyses. Discrepancies in the number of trials result from inaccurate specifications of endpoints in the publications. This distribution is reflected in the HTA-reports: while almost all reports on rheumatoid arthritis refer to PRO, this is only the case in about half of the reports on breast cancer.

Conclusions

As definition and classification of PRO are concerned, coherent concepts are found in the literature. Their operationalisation and implementation must be guided by scientific principles. The type and frequency of PRO used in clinical trials largely depend on the disease analysed. The HTA-community seems to pursue the utilization of PRO proactively – in case of missing data the need for further research is stated.

Blinding in clozapine trials: a problem and a potential solution

BACKGROUND

A methodological problem arises when efficacy of clozapine is compared with other antipsychotic medication in double blind randomized studies. Due to the risk of leucopenia and agranulocytosis, patients in the clozapine condition need to have regular blood testing. The problem is that in order to maintain blinding, patients in the comparison conditions need to undergo blood testing as well and this can lead to underestimation of treatment acceptability and efficacy of the comparators.

METHODS

A thought experiment considering all possible solutions for the methodological problem.

RESULTS

We propose a special study design that preserves randomization and blinding while at the same time prevents underestimation of the effect in the comparator treatments. In addition, the necessity for blood testing is limited to only a small number of patients who receive comparative treatments. The design involves initial randomization to a sub-study including clozapine and a small comparator arm or to a sub-study that includes only comparator arms. Blood testing is only necessary in the first sub-study.

DISCUSSION

Limitations of the proposed design are discussed. It is noted that this study design may offer a solution to similar situations where blood testing or other types of monitoring (e.g. as with lithium) is required in one but not in all of the treatment arms of a double blind randomized study.

A comparison of antidepressant trials using active and inert placebos

In placebo-controlled antidepressant trials, there are concerns that the double blind may be breached, which may bias results. Some trials have therefore used placebos containing active substances in order to mimic the side effects of antidepressants. This study set out to examine the impact of 'unblinding' by comparing the results of a meta-analysis of a sample of trials using ordinary inert placebos with a meta-analysis of trials using active placebos. An a priori sub-group analysis of trials conducted with inpatients and outpatients was carried out. Quality was assessed using a quality assessment instrument and meta-regression analysis was conducted to explore heterogeneity. Results of meta-analysis did not differ between trials using active placebos and trials using inert ones. However, results were strongly influenced by two large trials. When these were excluded trials using inert placebos showed greater antidepressant-placebo differences than trials using active placebos. There was very high heterogeneity especially among trials using inert placebos. Meta-regression analysis showed the only significant predictor of outcome was whether trials were conducted with inpatients or outpatients. Sub-group analysis showed significant differences between antidepressants and any type of placebo in trials conducted with outpatients but not in inpatient trials. Lack of data, heterogeneity and the influence of large studies limited the analysis. The integrity of the double blind design, its effect on results and the heterogeneity between studies, require further exploration in antidepressant trials.

Evaluation of the prophylactic potential of an immunomodulator against respiratory disease in calves

The prophylatic effect against respiratory disease in feedlot calves of an immunomodulator, based on an inactivated avipox virus preparation, was evaluated in a double blind, placebo controlled field trial. The effect of the immunomodulator on phagocytosis and on the reactivity of the lymphocytes was also tested.

On the day of arrival at the feedlots and 3 days later 257 calves were injected with either the immunomodulator or with placebo. All calves were then observed for respiratory disease and treatments were recorded. The immunomodulator did not reduce the frequency of disease, compared to the placebo. Thirty percent of the calves treated with the immunomodulator and 27 % of the controls were treated with antibiotics for respiratory disease.

The cell mediated immune reactivity of 7 calves treated with the immunomodulator and of 7 untreated calves was tested. Monocytes isolated from the animals were examined for their ability to ingest latex beads and lymphocytes from the animals were examined for their response to different mitogens. Sera from each of the two groups were also investigated for the effect on phagocytosis. No difference in these parameters was observed between the two groups.