Open-label Cluster-randomized Trial Research Articles

The effect of salt substitution on frequency and severity of headache: results from the SSaSS cluster-randomised controlled trial of 20,995 participants

BackgroundHeadache is one of the most common neurological symptoms. Headache disorders are associated with a high global burden of disease. Prior studies indicate that short-to-medium term sodium reduction reduces headache symptom. This study evaluated the effects of long-term reduced-sodium, added-potassium salt on headache frequency and severity in rural China.MethodsThe Salt substitute and stroke study (SSaSS) was an open-label cluster-randomised trial in rural China designed to evaluate the effect of salt substitution on mortality and cardiovascular events. Participants included adults with a history of prior stroke and those aged ≥60 years with uncontrolled high blood pressure (BP). Villages were randomly assigned in a 1:1 ratio either to intervention with salt substitute (75% sodium chloride and 25% potassium chloride by mass) or to control with continued use of regular salt (100% sodium chloride). In this pre-specified analysis, between-group differences in headache frequency and severity were evaluated. The study was registered with ClinicalTrials.gov (identifier number: NCT02092090).ResultsA total of 20,995 participants were included in the trial (mean age 64.3 years, 51% female, mean follow-up 4.7 years). At final follow-up at the end of the study, headache outcome data including frequency and severity of headaches was available for 16,486 (98%) of 16,823 living participants. Overall, 4454/16,486 (27%) individuals reported having headache: 27.4% in the intervention group (2301/8386) vs 26.6% in the control group (2153/8100) (RR 1.04, 95% CI: 0.93, 1.16, p = 0.48). There was no difference in headache severity between intervention and control groups (p = 0.90).ConclusionLong term salt substitution did not reduce the frequency or severity of headaches in this population.

Mortality in HIV and tuberculosis patients following implementation of integrated HIV-TB treatment: Results from an open-label cluster-randomized trial.

SummaryBackgroundHIV-TB treatment integration reduces mortality. Operational implementation of integrated services is challenging. This study assessed the impact of quality improvement (QI) for HIV-TB integration on mortality within primary healthcare (PHC) clinics in South Africa.MethodsAn open-label cluster randomized controlled study was conducted between 2016 and 2018 in 40 rural clinics in South Africa. The study statistician randomized PHC nurse-supervisors 1:1 into 16 clusters (eight nurse-supervisors supporting 20 clinics per arm) to receive QI, supported HIV-TB integration intervention or standard of care (control). Nurse supervisors and clinics under their supervision, based in the study health districts were eligible for inclusion in this study. Nurse supervisors were excluded if their clinics were managed by municipal health (different resource allocation), did not offer co-located antiretroviral therapy (ART) and TB services, services were performed by a single nurse, did not receive non-governmental organisation (NGO) support, patient data was not available for > 50% of attendees. The analysis population consists of all patients newly diagnosed with (i) both TB and HIV (ii) HIV only (among patients previously treated for TB or those who never had TB before) and (iii) TB only (among patients already diagnosed with HIV or those who were never diagnosed with HIV) after QI implementation in the intervention arm, or enrolment in the control arm. Mortality rates was assessed 12 months post enrolment, using unpaired t-tests and cox-proportional hazards model. (Clinicaltrials.gov, NCT02654613, registered 01 June 2015, trial closed).FindingsOverall, 21 379 participants were enrolled between December 2016 and December 2018 in intervention and control arm clinics: 1329 and 841 HIV-TB co-infected (10·2%); 10 799 and 6 611 people living with Human Immunodeficiency Virus (HIV)/ acquired immunodeficiency syndrome (AIDS) (PLWHA) only (81·4%); 1 131 and 668 patients with TB only (8·4%), respectively. Average cluster sizes were 1657 (range 170–5782) and 1015 (range 33–2027) in intervention and control arms. By 12 months, 6529 (68·7%) and 4074 (70·4%) were alive and in care, 568 (6·0%) and 321 (5·6%) had completed TB treatment, 1078 (11·3%) and 694 (12·0%) were lost to follow-up, with 245 and 156 deaths occurring in intervention and control arms, respectively. Mortality rates overall [95% confidence interval (CI)] was 4·5 (3·4–5·9) in intervention arm, and 3·8 (2·6–5·4) per 100 person-years in control arm clusters [mortality rate ratio (MRR): 1·19 (95% CI 0·79–1·80)]. Mortality rates among HIV-TB co-infected patients was 10·1 (6·7–15·3) and 9·8 (5·0–18·9) per 100 person-years, [MRR: 1·04 (95% CI 0·51–2·10)], in intervention and control arm clusters, respectively.InterpretationHIV-TB integration supported by a QI intervention did not reduce mortality in HIV-TB co-infected patients. Demonstrating mortality benefit from health systems process improvements in real-world operational settings remains challenging. Despite the study being potentially underpowered to demonstrate the effect size, integration interventions were implemented using existing facility staff and infrastructure reflecting the real-world context where most patients in similar settings access care, thereby improving generalizability and scalability of study findings.FundingResearch reported in this publication was supported by South African Medical Research Council (SAMRC), and UK Government's Newton Fund through United Kingdom Medical Research Council (UKMRC).

Smartphone-Based Telestroke Vs"Stroke Physician" led Acute Stroke Management (SMART INDIA): A Protocol for a Cluster-Randomized Trial.

Background:One of the major challenges is to deliver adequate health care in rural India, where more than two-thirds of India's population lives. There is a severe shortage of specialists in rural areas with one of the world's lowest physician/population ratios. There is only one neurologist per 1.25 million population. Stroke rehabilitation is virtually nonexistent in most district hospitals. Two innovative solutions include training physicians in district hospitals to diagnose and manage acute stroke ('Stroke physician model') and using a low-cost Telestroke model. We will be assessing the efficacy of these models through a cluster-randomized trial with a standard of care database maintained simultaneously in tertiary nodal centers with neurologists.Methods:SMART INDIA is a multicenter, open-label cluster-randomized trial with the hospital as a unit of randomization. The study will include district hospitals from the different states of India. We plan to enroll 22 district hospitals where a general physician manages the emergency without the services of a neurologist. These units (hospitals) will be randomized into either of two interventions using computer-generated random sequences with allocation concealment. Blinding of patients and clinicians will not be possible. The outcome assessment will be conducted by the blinded central adjudication team. The study includes 12 expert centers involved in the Telestroke arm by providing neurologists and telerehabilitation round the clock for attending calls. These centers will also be the training hub for “stroke physicians” where they will be given intensive short-term training for the management of acute stroke. There will be a preintervention data collection (1 month), followed by the intervention model implementation (3 months).Outcomes:The primary outcome will be the composite score (percentage) of performance of acute stroke care bundle assessed at 1 and 3 months after the intervention. The highest score (100%) will be achieved if all the eligible patients receive the standard stroke care bundle. The study will have an open-label extension for 3 more months.Conclusion:SMART INDIA assesses whether the low-cost Telestroke model is superior to the stroke physician model in achieving acute stroke care delivery. The results of this study can be utilized in national programs for stroke and can be a role model for stroke care delivery in low- and middle-Income countries. (CTRI/2021/11/038196)

Efficacy of pragmatic same-day ring prophylaxis for adult individuals exposed to SARS-CoV-2 in Switzerland (COPEP): protocol of an open-label cluster randomised trial

IntroductionLopinavir/ritonavir (LPV/r) has been proposed as repurposed drugs for pre-exposure and postexposure prophylaxis as well as therapy of COVID-19. Coronavirus postexposure prophylaxis (COPEP) trial aims at assessing their efficacy as...

Cardiovascular risk factor reduction by community health workers in rural India: A cluster randomized trial

There is a need to identify and test low-cost approaches for cardiovascular disease (CVD) risk reduction that can enable health systems to achieve such a strategy. Community health workers (CHWs) are an integral part of health-care delivery system in lower income countries. Our aim was to assess impact of CHW based interventions in reducing CVD risk factors in rural households in India. We performed an open-label cluster-randomized trial in 28 villages in 3 states of India with the household as a unit of randomization. Households with individuals at intermediate to high CVD risk were randomized to intervention and control groups. In the intervention group, trained CHWs delivered risk-reduction advice and monitored risk factors during 6 household visits over 12 months. Households in the non-intervention group received usual care. Primary outcomes were a reduction in systolic BP (SBP) and adherence to prescribed BP lowering drugs. We randomized 2312 households (3261 participants at intermediate or high risk) to intervention (1172 households) and control (1140 households). At baseline prevalence of tobacco use (48.5%) and hypertension (34.7%) were high. At 12 months, there was significant decline in SBP (mmHg) from baseline in both groups- controls 130.3 ± 21 to 128.3 ± 15; intervention 130.3 ± 21 to 127.6 ± 15 (P < .01 for before and after comparison) but there was no difference between the 2 groups at 12 months (P = .18). Adherence to antihypertensive drugs was greater in intervention vs control households (74.9% vs 61.4%, P = .001). A 12-month CHW-led intervention at household level improved adherence to prescribed drugs, but did not impact SBP. To be more impactful, a more comprehensive solution that addresses escalation and access to useful therapies is needed.

Community transmission of type 2 poliovirus after cessation of trivalent oral polio vaccine in Bangladesh: an open-label cluster-randomised trial and modelling study

SummaryBackgroundTrivalent oral polio vaccine (tOPV) was replaced worldwide from April, 2016, by bivalent types 1 and 3 oral polio vaccine (bOPV) and one dose of inactivated polio vaccine (IPV) where available. The risk of transmission of type 2 poliovirus or Sabin 2 virus on re-introduction or resurgence of type 2 poliovirus after this switch is not understood completely. We aimed to assess the risk of Sabin 2 transmission after a polio vaccination campaign with a monovalent type 2 oral polio vaccine (mOPV2).MethodsWe did an open-label cluster-randomised trial in villages in the Matlab region of Bangladesh. We randomly allocated villages (clusters) to either: tOPV at age 6 weeks, 10 weeks, and 14 weeks; or bOPV at age 6 weeks, 10 weeks, and 14 weeks and either one dose of IPV at age 14 weeks or two doses of IPV at age 14 weeks and 18 weeks. After completion of enrolment, we implemented an mOPV2 vaccination campaign that targeted 40% of children younger than 5 years, regardless of enrolment status. The primary outcome was Sabin 2 incidence in the 10 weeks after the campaign in per-protocol infants who did not receive mOPV2, as assessed by faecal shedding of Sabin 2 by reverse transcriptase quantitative PCR (RT-qPCR). The effect of previous immunity on incidence was also investigated with a dynamical model of poliovirus transmission to observe prevalence and incidence of Sabin 2 virus. This trial is registered at ClinicalTrials.gov, number NCT02477046.FindingsBetween April 30, 2015, and Jan 14, 2016, individuals from 67 villages were enrolled to the study. 22 villages (300 infants) were randomly assigned tOPV, 23 villages (310 infants) were allocated bOPV and one dose of IPV, and 22 villages (329 infants) were assigned bOPV and two doses of IPV. Faecal shedding of Sabin 2 in infants who did not receive the mOPV2 challenge did not differ between children immunised with bOPV and one or two doses of IPV and those who received tOPV (15 of 252 [6%] vs six of 122 [4%]; odds ratio [OR] 1·29, 95% CI 0·45–3·72; p=0·310). However, faecal shedding of Sabin 2 in household contacts was increased significantly with bOPV and one or two doses of IPV compared with tOPV (17 of 751 [2%] vs three of 353 [1%]; OR 3·60, 95% CI 0·82–15·9; p=0·045). Dynamical modelling of within-household incidence showed that immunity in household contacts limited transmission.InterpretationIn this study, simulating 1 year of tOPV cessation, Sabin 2 transmission was higher in household contacts of mOPV2 recipients in villages receiving bOPV and either one or two doses of IPV, but transmission was not increased in the community as a whole as shown by the non-significant difference in incidence among infants. Dynamical modelling indicates that transmission risk will be higher with more time since cessation.FundingBill & Melinda Gates Foundation.

Can we reduce bias in open-label trials when blinded outcome assessment is not possible? An example from the trigger trial

Blinded outcome assessment is a key component of randomised trials, as unblinded assessment can lead to bias. However, in some circumstances blinded assessment may be difficult to achieve. In these situations, it may be useful to modify the outcome definition to remove the most subjective elements, thereby reducing the risk of bias. This is the approach used in TRIGGER, an open-label cluster-randomised trial in patients with acute upper gastrointestinal bleeding. The primary clinical outcome was further bleeding. Blinded outcome assessment was impossible, as all clinicians throughout a hospital were aware of the treatment allocation due to the use of cluster-randomisation, and given the emergency nature of the condition, it was not possible to compile relevant information to send to an adjudication committee in a blinded matter. We therefore modified the outcome definition to remove subjective events (e.g. if a patient vomited blood, whether it was ‘fresh’ enough to indicate a new bleed), leaving only relatively objective events (the presence vs. absence of blood in the patient's upper gastrointestinal tract, based on a visual inspection by endoscopy). We collected both outcomes (including vs. removing subjective events) during the trial, and compared the estimated treatment effects from both. Including subjective events led to an odds ratio (OR) of 0.83 (95% CI 0.50 to 1.37), compared to an OR of 0.50 (95% CI 0.32 to 0.78) after removing subjective events. The ratio of odds ratios was 1.66, indicating that including subjective events may biased the treatment effect upwards by 66%.