Balancing benefits and potential risks of vaccination: the precautionary principle and the law of unintended consequences

Vaccination is a life-saving endeavour, yet risk and uncertainty are unavoidable in science and medicine. Vaccination remains contentious in the public mind, and vaccine hesitancy is a serious public health issue. This has recently been reignited in the discussion over potential side effects of COVID-19 vaccines, and the decision by several countries to suspend measures such as the AstraZeneca vaccine. In these instances, the precautionary principle has often been invoked as a rationale, yet such heuristics do not adequately weigh potential harms against real benefits. How we analyse, communicate and react to potential harms is absolutely paramount to ensure the best decisions and outcomes for societal health, and maintaining public confidence. While balancing benefits and risks is an essential undertaking, it cannot be achieved without due consideration of several other pertinent factors, especially in the context of vaccination, where misguided or exaggerated fears have in the past imperilled public health. While well meaning, over reactions to potential hazards of vaccination and other health interventions can have unintended consequences, and cause lingering damage to public trust. In this analysis, we explore the challenges of assessing risk and benefit, and the limitations of the precautionary principle in these endeavours. When risk is unclear, cautious vigilance might be a more pragmatic and useful policy than reactionary suspensions.

Density strips: visualisation of uncertainty in clinical data summaries and research findings

The disproportionate focus on statistical significance in reporting and interpreting clinical research studies contributes to publication bias and encourages selective reporting. This highlights a need for alternative approaches that clearly communicate the uncertainty in the data, enabling researchers to provide a more nuanced interpretation of clinical research findings.Our purpose in this article is to introduce the density strip method as one potential approach that might act as a bridge between data visualisation for descriptive purposes and formal statistical inference. We build on existing theory, translating it to the applied research context to illustrate its utility to clinical researchers.We achieve this by considering an exemplar clinical trial, Multiple Sclerosis-Secondary Progressive Multi-Arm Randomisation Trial (MS-SMART). MS-SMART was a multiarm randomised placebo-controlled trial of three potentially neuroprotective drugs in secondary progressive MS. We illustrate through MS-SMART the potential of the density strip as an effective visualisation of the distribution of clinical trial outcomes and as a complementary approach to aid the interpretation of formal, inferential, statistical analysis.We conclude by summarising the advantages and disadvantages of the density strip methodology and provide suggestions for its potential extensions and possible further uses.

Risks of infection, hospital and ICU admission, and death from COVID-19 in people with asthma: systematic review and meta-analyses

ObjectivesTo determine if and to what degree asthma may predispose to worse COVID-19 outcomes in order to inform treatment and prevention decisions, including shielding and vaccine prioritisation.DesignSystematic review and meta-analysis.SettingElectronic databases were searched (October 2020) for clinical studies reporting at least one of the following stratified by asthma status: risk of infection with SARS-CoV-2; hospitalisation, intensive care unit (ICU) admission or mortality with COVID-19.ParticipantsAdults and children who tested positive for or were suspected to have COVID-19.Main outcome measuresMain outcome measures were the following stratified by asthma status: risk of infection with SARS-CoV-2; hospitalisation, ICU admission or mortality with COVID-19. We pooled odds ratios (ORs) and presented these with 95% confidence intervals (CI). Certainty was assessed using GRADE (Grading of Recommendations, Assessment, Development and Evaluations).Results30 (n=112 420) studies were included (12 judged high quality, 15 medium, 3 low). Few provided indication of asthma severity. Point estimates indicated reduced risks in people with asthma for all outcomes, but in all cases the evidence was judged to be of very low certainty and 95% CIs all included no difference and the possibility of increased risk (death: OR 0.90, 95% CI 0.72 to 1.13, I2=58%; hospitalisation: OR 0.95, 95% CI 0.71 to 1.26; ICU admission: OR 0.96, 95% CI 0.75 to 1.24). Findings on hospitalisation are also limited by substantial unexplained statistical heterogeneity. Within people with asthma, allergic asthma was associated with less COVID-19 risk and concurrent chronic obstructive pulmonary disease was associated with increased risk. In some studies, corticosteroids were associated with increased risk, but this may reflect increased risk in people with more severe asthma.ConclusionsThough absence of evidence of a clear association between asthma and worse outcomes from COVID-19 should not be interpreted as evidence of absence, the data reviewed indicate that risks from COVID-19 in people with asthma, as a whole, may be less than originally anticipated.

Registration of health and medical research

Registration of health and medical research is an effective way of improving the transparency and credibility of evidence. Registration involves pre-specifying the research objectives, design, methods and analytic plan on a publicly accessible repository before conducting the study. Registration can reduce bias and improve the transparency and credibility of research findings. Registration is mandated for clinical trials, but it is also relevant to systematic reviews, observational and preclinical experimental research. This paper describes how researchers can register their research and outlines possible barriers and challenges in doing so. Widespread adoption of research registration can reduce research waste and improve evidence-informed clinical and policy decision making.

Preventable deaths from SARS-CoV-2 in England and Wales: a systematic case series of coroners’ reports during the COVID-19 pandemic

ObjectivesTo examine coroners’ Prevention of Future Deaths (PFDs) reports to identify deaths involving SARS-CoV-2 that coroners deemed preventable.DesignConsecutive case series.SettingEngland and Wales.ParticipantsPatients reported in 510 PFDs dated between 01 January 2020 and 28 June 2021, collected from the UK’s Courts and Tribunals Judiciary website using web scraping to create an openly available database: https://preventabledeathstrackernet/.Main outcome measuresConcerns reported by coroners.ResultsSARS-CoV-2 was involved in 23 deaths reported by coroners in PFDs. Twelve deaths were indirectly related to the COVID-19 pandemic, defined as those that were not medically caused by SARS-CoV-2, but were associated with mitigation measures. In 11 cases, the coroner explicitly reported that COVID-19 had directly caused death. There was geographical variation in the reporting of PFDs; most (39%) were written by coroners in the North West of England. The coroners raised 56 concerns, problems in communication being the most common (30%), followed by failure to follow protocols (23%). Organisations in the National Health Service were sent the most PFDs (51%), followed by the government (26%), but responses to PFDs by these organisations were poor.ConclusionsPFDs contain a rich source of information on preventable deaths that has previously been difficult to examine systematically. Our openly available tool (https://preventabledeathstracker.net/) streamlines this process and has identified many concerns raised by coroners that should be addressed during the government’s inquiry into the handling of the COVID-19 pandemic, so that mistakes made are less likely to be repeated.Study protocol preregistrationhttps://osf.io/bfypc/.