Biases in Evaluating the Safety and Effectiveness of Drugs for the Treatment of COVID-19: Designing Real-World Evidence Studies

Effectiveness of Treating Obstructive Sleep Apnea by Surgeries and Continuous Positive Airway Pressure: Evaluation Using Objective Sleep Parameters and Patient-Reported Outcomes

Background/Objectives: Uvulopalatopharyngoplasty (UPPP), palatal plus nasal surgery (PNS), and continuous positive airway pressure (CPAP) are widely implemented treatments for obstructive sleep apnea (OSA). This study aims to explore the long-term effects on objective sleep parameters and patient-reported outcomes (PROs) following different therapeutic interventions for OSA. Methods: Data from patients with moderate-to-severe OSA were retrospectively collected from a medical center and a regional hospital, spanning from December 2011 to August 2018. Objective evaluations included the Apnea-Hypopnea Index (AHI), minimum O2 saturation, and sleep efficiency. The PROs consisted of the Snore Outcomes Survey and Epworth Sleepiness Scale. Using mixed-effects models, we evaluated longitudinal changes in sleep parameters and PROs, accounting for repeated measures and variations within individuals over time. Results: Among 448 patients with moderate-to-severe OSA, follow-up data were collected for 42 patients undergoing UPPP surgery, 171 undergoing PNS, 127 using CPAP, and 108 in the non-treated group. The mean follow-up was 16.7 months (SD = 11.9, range: 1.6-77.3). Significant improvements were observed in AHI, minimum O2 saturation, and hypersomnia immediately following interventions with UPPP, PNS, and CPAP therapy (p < 0.05). Moreover, the analysis revealed no significant rate of change in these parameters over time, suggesting that the benefits of these treatments were sustained in the long term. Furthermore, all interventions exhibited a significant short-term effect on self-reported snoring when compared to the control group, with a p-value of less than 0.001. However, the magnitude of this improvement gradually decreased over time. The snore scores seemed to return to pre-treatment levels among the UPPP, PNS, and CPAP groups after averages of 46.4, 63.5, and 74.4 months, respectively (all p < 0.05). Conclusions: Surgical interventions and CPAP therapy showed potential long-term effectiveness in managing OSA. Snoring symptoms reappeared about 3.9-5.3 years after surgical treatments, which seemed earlier than the average of 6.2 years in patients receiving CPAP and should be considered in patient-participatory decision-making processes.

Assessing the benefit-risk balance of drugs. Some lessons from the COVID pandemic

INTRODUCTION

Drug efficacy and effectiveness are assessed respectively through clinical trials and pharmaco-epidemiological studies. However, relative and absolute benefits of drugs are distinct measures that must be considered in relation to the baseline risk of disease incidence, complication or progression. On the other hand, adverse drug reactions are independent of the basic risk but depend on the characteristics of the population treated. Given these prerequisites, how can we balance the benefits and risks of drugs?

AREAS COVERED

We use the example of therapeutics evaluated during Covid to describe how assessing the benefit-risk balance of drugs is a complex process.

EXPERT OPINION

Clinical trials are not designed to identify rare adverse events, underscoring the necessity for a pharmacovigilance system. Evaluating the balance between the benefits and risks of drugs is an ongoing process, demanding the simultaneous analysis of data from clinical trials, potential drug-drug interactions, pharmacovigilance monitoring and pharmaco-epidemiological studies, to identify potential safety concerns. In addition, pharmacologists must play a major role in educating the general public about drugs, aiding in the accurate interpretation of the benefit-risk balance and preventing misinformation.

Effectiveness of azvudine against severe outcomes among hospitalized COVID-19 patients in Xinjiang, China: a single-center, retrospective, matched cohort study

BACKGROUND

Since the end of 2022, Azvudine was widely used to treat hospitalized coronavirus disease 2019 (COVID-19) patients in China. However, data on the real-world effectiveness of Azvudine against severe outcomes and post-COVID-19-conditions (PCC) among patients infected by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron variants was limited. This study evaluates the effectiveness of Azvudine in hospitalized COVID-19 patients during a SARS-CoV-2 Omicron BA.5 dominance period.

METHODS

From 1 November 2022 to 1 July 2023, an SARS-CoV-2 Omicron BA.5 dominant period, we conducted a single-center retrospective cohort study based on hospitalized patients with laboratory-confirmed SARS-CoV-2 infection from a tertiary hospital in Shihezi, China. Patients treated with Azvudine and usual care were propensity-score matched (PSM) at a 1:1 ratio to a control group in which patients received usual care only, with matching based on covariates such as sex, age, ethnicity, number of preexisting conditions, antibiotic use at admission, and baseline complete blood cell count. The primary outcomes were all-cause death and short-term (60 days) PCC post discharge. The secondary outcomes included the initiation of invasive mechanical ventilation and PCC at long-term post discharge (120 days). Cox proportional hazards (PH) regression models were employed to estimate the hazard ratios (HR) of Azvudine treatment for both all-cause death and invasive mechanical ventilation, and logistic regression models were used to estimate the odds ratios (OR) for short-term and long-term PCC. Subgroup analyses were performed based on a part of the matched covariates.

RESULTS

A total of 2,639 hospitalized patients with SARS-CoV-2 infection were initially identified, and 2,069 ineligible subjects were excluded from analyses. After matching, 297 Azvudine recipients and 297 matched controls were eligible for analyses. The incidence rate of all-cause death was relatively lower in the Azvudine group than in control group (0.007 per person, 95% confidence interval [CI]: 0.001, 0.024 vs 0.128, 95% CI: 0.092, 0.171), and the use of Azvudine was associated with a significantly lower risk of death (HR: 0.049, 95% CI: 0.012, 0.205). Subgroup analyses suggested protection of Azvudine against the risks of all-cause death among men, age over 65, patients without the preexisting conditions, and patients with antibiotics dispensed at admission. Statistical differences were not observed between the Azvudine group and the control group for the risks of invasive mechanical ventilation or short and long-term PCC.

CONCLUSIONS

Our findings indicated that Azvudine was associated with lower risk of all-cause death among hospitalized patients with Omicron BA.5 infection in a real-world setting. Further investigation is needed to explore the effectiveness of Azvudine against the PCC after discharge.

A Critical Analysis of All-Cause Deaths during COVID-19 Vaccination in an Italian Province

Immortal time bias (ITB) is common in cohort studies and distorts the association estimates between the treated and untreated. We used data from an Italian study on COVID-19 vaccine effectiveness, with a large cohort, long follow-up, and adjustment for confounding factors, affected by ITB, with the aim to verify the real impact of the vaccination campaign by comparing the risk of all-cause death between the vaccinated population and the unvaccinated population. We aligned all subjects on a single index date and considered the "all-cause deaths" outcome to compare the survival distributions of the unvaccinated group versus various vaccination statuses. The all-cause-death hazard ratios in univariate analysis for vaccinated people with 1, 2, and 3/4 doses versus unvaccinated people were 0.88, 1.23, and 1.21, respectively. The multivariate values were 2.40, 1.98, and 0.99. Possible explanations of this trend of the hazard ratios as vaccinations increase could be a harvesting effect; a calendar-time bias, accounting for seasonality and pandemic waves; a case-counting window bias; a healthy-vaccinee bias; or some combination of these factors. With 2 and even with 3/4 doses, the calculated Restricted Mean Survival Time and Restricted Mean Time Lost have shown a small but significant downside for the vaccinated populations.

Methodological biases in observational hospital studies of COVID-19 treatment effectiveness: pitfalls and potential

Introduction

This study aims to discuss and assess the impact of three prevalent methodological biases: competing risks, immortal-time bias, and confounding bias in real-world observational studies evaluating treatment effectiveness. We use a demonstrative observational data example of COVID-19 patients to assess the impact of these biases and propose potential solutions.

Methods

We describe competing risks, immortal-time bias, and time-fixed confounding bias by evaluating treatment effectiveness in hospitalized patients with COVID-19. For our demonstrative analysis, we use observational data from the registry of patients with COVID-19 who were admitted to the Bellvitge University Hospital in Spain from March 2020 to February 2021 and met our predefined inclusion criteria. We compare estimates of a single-dose, time-dependent treatment with the standard of care. We analyze the treatment effectiveness using common statistical approaches, either by ignoring or only partially accounting for the methodological biases. To address these challenges, we emulate a target trial through the clone-censor-weight approach.

Results

Overlooking competing risk bias and employing the naïve Kaplan-Meier estimator led to increased in-hospital death probabilities in patients with COVID-19. Specifically, in the treatment effectiveness analysis, the Kaplan-Meier estimator resulted in an in-hospital mortality of 45.6% for treated patients and 59.0% for untreated patients. In contrast, employing an emulated trial framework with the weighted Aalen-Johansen estimator, we observed that in-hospital death probabilities were reduced to 27.9% in the "X"-treated arm and 40.1% in the non-"X"-treated arm. Immortal-time bias led to an underestimated hazard ratio of treatment.

Conclusion

Overlooking competing risks, immortal-time bias, and confounding bias leads to shifted estimates of treatment effects. Applying the naïve Kaplan-Meier method resulted in the most biased results and overestimated probabilities for the primary outcome in analyses of hospital data from COVID-19 patients. This overestimation could mislead clinical decision-making. Both immortal-time bias and confounding bias must be addressed in assessments of treatment effectiveness. The trial emulation framework offers a potential solution to address all three methodological biases.

Bias in observational studies on the effectiveness of in hospital use of hydroxychloroquine in COVID-19

PURPOSE

During the first waves of the coronavirus pandemic, evidence on potential effective treatments was urgently needed. Results from observational studies on the effectiveness of hydroxychloroquine (HCQ) were conflicting, potentially due to biases. We aimed to assess the quality of observational studies on HCQ and its relation to effect sizes.

METHODS

PubMed was searched on 15 March 2021 for observational studies on the effectiveness of in-hospital use of HCQ in COVID-19 patients, published between 01/01/2020 and 01/03/2021 on. Study quality was assessed using the ROBINS-I tool. Association between study quality and study characteristics (journal ranking, publication date, and time between submission and publication) and differences between effects sizes found in observational studies compared to those found in RCTs, were assessed using Spearman's correlation.

RESULTS

Eighteen of the 33 (55%) included observational studies were scored as critical risk of bias, eleven (33%) as serious risk and only four (12%) as moderate risk of bias. Biases were most often scored as critical in the domains related to selection of participants (n = 13, 39%) and bias due to confounding (n = 8, 24%). There were no significant associations found between the study quality and the characteristics nor between the study quality and the effect estimates.

DISCUSSION

Overall, the quality of observational HCQ studies was heterogeneous. Synthesis of evidence of effectiveness of HCQ in COVID-19 should focus on RCTs and carefully consider the added value and quality of observational evidence.

A Road Map for Peer Review of Real-World Evidence Studies on Safety and Effectiveness of Treatments

The growing acceptance of real-world evidence (RWE) in clinical and regulatory decision-making, coupled with increasing availability of health care data and advances in automated analytic approaches, has contributed to a marked expansion of RWE studies of diabetes and other diseases. However, a recent spate of high-profile retractions highlights the need for improvements in the conduct of RWE research as well as in the associated peer review and editorial processes. We review best pharmacoepidemiologic practices and common pitfalls regarding design, measurement, analysis, data validity, appropriateness, and generalizability of RWE studies. To enhance RWE study assessments, we propose that journal editors require 1) study authors to complete RECORD-PE, a reporting guideline for pharmacoepidemiological studies on routinely collected data, 2) availability of predetermined study protocols and analysis plans, 3) inclusion of pharmacoepidemiologists on the peer review team, and 4) provision of detail on data provenance, characterization, and custodianship to facilitate assessment of the data source. We recognize that none of these steps guarantees a high-quality research study. Collectively, however, they permit an informed assessment of whether the study was adequately designed and conducted and whether the data source used was fit for purpose.

Oral Azvudine for hospitalised patients with COVID-19 and pre-existing conditions: a retrospective cohort study

Background

As the COVID-19 pandemic continues to spread, the number of associated deaths continues to increase, especially among those with pre-existing conditions. Azvudine is recommended as a priority treatment for patients with COVID-19, but its efficacy in patients with pre-existing conditions is unknown.

Methods

This is a single-centre, retrospective cohort study between December 5, 2022 and January 31, 2023 in Xiangya Hospital of Central South University in China to evaluate the clinical efficacy of Azvudine in hospitalised patients with COVID-19 and pre-existing conditions. Patients with Azvudine and controls were propensity score-matched (1:1) for age, gender, vaccination status, time from symptom onset to treatment exposure, severity at admission, concomitant treatments initiated at admission. The primary outcome was a composite outcome of disease progression, and the secondary outcome was each of these individual disease progression outcomes. The univariate Cox regression model was used to estimate a hazard ratio (HR) with 95% confidence interval (CI) for each result between the groups.

Findings

We identified 2118 hospitalised patients with COVID-19 during the study period, with a follow-up of up to 38 days. After exclusions and propensity score matching, we included 245 Azvudine recipients and 245 matched controls. Azvudine recipients had lower crude incidence rate of composite disease progression outcome compared with matched controls (7.125/1000 person-days vs. 16.004/1000 person-days, P = 0.018). There was no significant difference in all-cause death between these two groups (1.934/1000 person-days vs. 4.128/1000 person-days, P = 0.159). Azvudine treatment was associated with significantly lower risks of composite disease progression outcome compared with matched controls (HR: 0.49; 95% CI: 0.27-0.89, P = 0.016). A significant difference in all-cause death was not found (HR: 0.45; 95% CI: 0.15-1.36, P = 0.148).

Interpretation

These findings indicate that Azvudine therapy showed substantial clinical benefits in hospitalised patients with COVID-19 and pre-existing conditions, and should be considered for this population of patients.

Funding

This work was supported by the National Natural Science Foundation of China (Grant Nos. 82103183 to F. Z., 82102803, 82272849 to G. D.), National Natural Science Foundation of Hunan Province (Grant Nos. 2022JJ40767 to F. Z., 2021JJ40976 to G. D.), Huxiang Youth Talent Program (Grant Nos. 2022RC1014 to M.S.) and Ministry of Industry and Information Technology of China (Grant Nos. TC210804V to M.S.).

Target Trial Emulation Using Hospital-Based Observational Data: Demonstration and Application in COVID-19

Methodological biases are common in observational studies evaluating treatment effectiveness. The objective of this study is to emulate a target trial in a competing risks setting using hospital-based observational data. We extend established methodology accounting for immortal time bias and time-fixed confounding biases to a setting where no survival information beyond hospital discharge is available: a condition common to coronavirus disease 2019 (COVID-19) research data. This exemplary study includes a cohort of 618 hospitalized patients with COVID-19. We describe methodological opportunities and challenges that cannot be overcome applying traditional statistical methods. We demonstrate the practical implementation of this trial emulation approach via clone-censor-weight techniques. We undertake a competing risk analysis, reporting the cause-specific cumulative hazards and cumulative incidence probabilities. Our analysis demonstrates that a target trial emulation framework can be extended to account for competing risks in COVID-19 hospital studies. In our analysis, we avoid immortal time bias, time-fixed confounding bias, and competing risks bias simultaneously. Choosing the length of the grace period is justified from a clinical perspective and has an important advantage in ensuring reliable results. This extended trial emulation with the competing risk analysis enables an unbiased estimation of treatment effects, along with the ability to interpret the effectiveness of treatment on all clinically important outcomes.

Real-world effectiveness of early molnupiravir or nirmatrelvir-ritonavir in hospitalised patients with COVID-19 without supplemental oxygen requirement on admission during Hong Kong's omicron BA.2 wave: a retrospective cohort study

BACKGROUND

Data on the effectiveness of oral antivirals in patients with mild-to-moderate COVID-19 are urgently needed. This retrospective cohort study aimed to evaluate the clinical and virological outcomes associated with molnupiravir or nirmatrelvir-ritonavir use in hospitalised patients with mild-to-moderate COVID-19 during a pandemic wave dominated by the omicron BA.2 subvariant.

METHODS

We analysed data from a territory-wide retrospective cohort of patients in Hong Kong who were hospitalised with a confirmed diagnosis of SARS-CoV-2 infection between Feb 26 and April 26, 2022. Data were extracted from the Hospital Authority, the Department of Health, and the Hong Kong Death Registry. Patients were eligible for inclusion if their admission date was within 3 days before or after confirmation of their COVID-19 diagnosis. Those who were admitted to hospital more than 5 days after symptom onset, were younger than 18 years, had a history of oral antiviral use before admission, required supplemental oxygen on admission, had drug-related contraindications to nirmatrelvir-ritonavir use, or had severe renal or severe liver impairment were excluded. Patients who received the oral antivirals molnupiravir or nirmatrelvir-ritonavir were matched with controls using propensity-score matching in a ratio of 1:1. The primary outcome was all-cause mortality and secondary outcomes included a composite outcome of disease progression (all-cause mortality, initiation of invasive mechanical ventilation [IMV], intensive care unit [ICU] admission, or the need for oxygen therapy) and each of these individual disease progression outcomes, and time to reaching a low viral burden (RT-PCR cycle threshold value ≥30). For each event outcome, crude incidence rates were calculated and hazard ratios (HRs) estimated using Cox regression models.

FINDINGS

We identified 40 776 patients hospitalised with SARS-CoV-2 infection during the study period, with a mean follow-up of 41·3 days (total 925 713 person-days). After exclusions and propensity-score matching, we included 1856 molnupiravir recipients and 1856 matched controls, and 890 nirmatrelvir-ritonavir recipients and 890 matched controls. A lower risk of all-cause mortality was observed in molnupiravir recipients (crude incidence rate per 10 000 person-days 19·98 events [95% CI 16·91-23·45]) versus matched controls (38·07 events [33·85-42·67]; HR 0·48 [95% CI 0·40-0·59], p<0·0001) and in nirmatrelvir-ritonavir recipients (10·28 events [7·03-14·51]) versus matched controls (26·47 events [21·34-32·46]; HR 0·34 [0·23-0·50], p<0·0001). Oral antiviral recipients also had lower risks of the composite disease progression outcome (molnupiravir HR 0·60 [95% CI 0·52-0·69], p<0·0001; nirmatrelvir-ritonavir 0·57 [0·45-0·72], p<0·0001) and need for oxygen therapy (molnupiravir 0·69 [0·57-0·83], p=0·0001; nirmatrelvir-ritonavir 0·73 [0·54-0·97], p=0·032) compared with controls. Time to achieving a low viral burden was significantly shorter among oral antiviral recipients than matched controls (molnupiravir HR 1·38 [95% CI 1·15-1·64], p=0·0005; nirmatrelvir-ritonavir 1·38 [1·07-1·79], p=0·013). Significant differences in initiation of IMV and ICU admission were not found.

INTERPRETATION

During a wave of SARS-CoV-2 omicron BA.2, initiation of novel oral antiviral treatments in hospitalised patients not requiring oxygen therapy on admission showed substantial clinical benefit. Our findings support the early use of oral antivirals in this population of patients.

FUNDING

Health and Medical Research Fund (Health Bureau, Government of the Hong Kong Special Administrative Region).

TRANSLATION

For the Chinese translation of the abstract see Supplementary Materials section.

Real-world Evidence of the Effects of Novel Treatments for COVID-19 on Mortality: A Nationwide Comparative Cohort Study of Hospitalized Patients in the First, Second, Third, and Fourth Waves in the Netherlands

Background

Large clinical trials on drugs for hospitalized coronavirus disease 2019 (COVID-19) patients have shown significant effects on mortality. There may be a discrepancy with the observed real-world effect. We describe the clinical characteristics and outcomes of hospitalized COVID-19 patients in the Netherlands during 4 pandemic waves and analyze the association of the newly introduced treatments with mortality, intensive care unit (ICU) admission, and discharge alive.

Methods

We conducted a nationwide retrospective analysis of hospitalized COVID-19 patients between February 27, 2020, and December 31, 2021. Patients were categorized into waves and into treatment groups (hydroxychloroquine, remdesivir, neutralizing severe acute respiratory syndrome coronavirus 2 monoclonal antibodies, corticosteroids, and interleukin [IL]-6 antagonists). Four types of Cox regression analyses were used: unadjusted, adjusted, propensity matched, and propensity weighted.

Results

Among 5643 patients from 11 hospitals, we observed a changing epidemiology during 4 pandemic waves, with a decrease in median age (67-64 years; P < .001), in in-hospital mortality on the ward (21%-15%; P < .001), and a trend in the ICU (24%-16%; P = .148). In ward patients, hydroxychloroquine was associated with increased mortality (1.54; 95% CI, 1.22-1.96), and remdesivir was associated with a higher rate of discharge alive within 29 days (1.16; 95% CI, 1.03-1.31). Corticosteroids were associated with a decrease in mortality (0.82; 95% CI, 0.69-0.96); the results of IL-6 antagonists were inconclusive. In patients directly admitted to the ICU, hydroxychloroquine, corticosteroids, and IL-6 antagonists were not associated with decreased mortality.

Conclusions

Both remdesivir and corticosteroids were associated with better outcomes in ward patients with COVID-19. Continuous evaluation of real-world treatment effects is needed.

Association of Remdesivir Treatment With Mortality Among Hospitalized Adults With COVID-19 in the United States

Importance

SARS-CoV-2, which causes COVID-19, poses considerable morbidity and mortality risks. Studies using data collected during routine clinical practice can supplement randomized clinical trials to provide needed evidence, especially during a global pandemic, and can yield markedly larger sample sizes to assess outcomes for important patient subgroups.

Objective

To evaluate the association of remdesivir treatment with inpatient mortality among patients with COVID-19 outside of the clinical trial setting.

Design, Setting, and Participants

A retrospective cohort study in US hospitals using health insurance claims data linked to hospital chargemaster data from December 1, 2018, to May 3, 2021, was conducted among 24 856 adults hospitalized between May 1, 2020, and May 3, 2021, with newly diagnosed COVID-19 who received remdesivir and 24 856 propensity score-matched control patients.

Exposure

Remdesivir treatment.

Main Outcomes and Measures

All-cause inpatient mortality within 28 days of the start of remdesivir treatment for the remdesivir-exposed group or the matched index date for the control group.

Results

A total of 24 856 remdesivir-exposed patients (12 596 men [50.7%]; mean [SD] age, 66.8 [15.4] years) and 24 856 propensity score-matched control patients (12 621 men [50.8%]; mean [SD] age, 66.8 [15.4] years) were included in the study. Median follow-up was 6 days (IQR, 4-11 days) in the remdesivir group and 5 days (IQR, 2-10 days) in the control group. There were 3557 mortality events (14.3%) in the remdesivir group and 3775 mortality events (15.2%) in the control group. The 28-day mortality rate was 0.5 per person-month in the remdesivir group and 0.6 per person-month in the control group. Remdesivir treatment was associated with a statistically significant 17% reduction in inpatient mortality among patients hospitalized with COVID-19 compared with propensity score-matched control patients (hazard ratio, 0.83 [95% CI, 0.79-0.87]).

Conclusions and Relevance

In this retrospective cohort study using health insurance claims and hospital chargemaster data, remdesivir treatment was associated with a significantly reduced inpatient mortality overall among patients hospitalized with COVID-19. Results of this analysis using data collected during routine clinical practice and state-of-the-art methods complement results from randomized clinical trials. Future areas of research include assessing the association of remdesivir treatment with inpatient mortality during the circulation of different variants and relative to time from symptom onset.

Challenges in evaluating treatments for COVID-19: The case of in-hospital anticoagulant use and the risk of adverse outcomes

Anticoagulants are a potential treatment for the thrombotic complications resulting from COVID-19. We aimed to determine the association between anticoagulant use and adverse outcomes among hospitalized patients with COVID-19. We used data from the COVID-19 International Collaborative Research Project in South Korea from January to June 2020. We defined exposure using an intention-to-treat approach, with person-time classified as use or non-use of anticoagulants at cohort entry, and a time-varying approach. The primary outcome was all-cause, in-hospital mortality; the secondary outcome was a composite including respiratory outcomes, cardiovascular outcomes, venous thromboembolism, major bleeding, and intensive care unit admission. Cox proportional hazards models estimated adjusted hazard ratios (HRs) of the outcomes comparing use versus non-use of anticoagulants. Our cohort included 2,677 hospitalized COVID-19 patients, of whom 24 received anticoagulants at cohort entry. Users were older and had more comorbidities. The crude incidence rate (per 1,000 person-days) of mortality was 5.83 (95% CI: 2.80, 10.72) among anticoagulant users and 1.36 (95% CI: 1.14, 1.59) for non-users. Crude rates of the composite outcome were 3.20 (95% CI: 1.04, 7.47) and 1.80 (95% CI: 1.54, 2.08), respectively. Adjusted HRs for mortality (HR: 1.12, 95% CI: 0.48, 2.64) and the composite outcome (HR: 0.79, 95% CI: 0.28, 2.18) were inconclusive. Although our study was not able to draw conclusions on anticoagulant effectiveness for COVID-19 outcomes, these results can contribute to future knowledge syntheses of this important question. Our study demonstrated that the dynamic pandemic environment may have important implications for observational studies of COVID-19 treatment effectiveness.

The challenges and opportunities in using real-world data to drive advances in healthcare in East Asia: expert panel recommendations

OBJECTIVE

To provide recommendations for overcoming the challenges associated with the generation and use of real-world evidence (RWE) in regulatory approvals, health technology assessments (HTAs), and reimbursement decision-making in East Asia.

METHODS

A panel of experts convened at the International Society for Pharmacoeconomics and Outcomes Research Asia Pacific 2020 congress to discuss the challenges limiting the use of RWE in healthcare decision-making and to provide insights into the perspectives of regulators, HTA agencies, the pharmaceutical industry, and physicians in China, Japan, and Taiwan. A nonsystematic literature review was conducted to expand on the themes addressed.

RESULTS

The use of RWE in regulatory approvals, HTAs, and reimbursement decision-making remains limited by legal/regulatory, technical, and attitudinal challenges in East Asia.

CONCLUSIONS

We recommend approaches and initiatives that aim to drive improvements in the utilization of RWE in healthcare decision-making in East Asia and other regions. We encourage large-scale collaborations that leverage the full range of skills offered by different stakeholders. Government agencies, hospitals, research organizations, patient groups, and the pharmaceutical industry must collaborate to ensure appropriate access to robust and reliable real-world data and seek alignment on how to address prioritized evidence needs. Increasingly, we believe that this work will be conducted by multidisciplinary teams with expertise in healthcare research and delivery, data science, and information technology. We hope this work will encourage further discussion among all stakeholders seeking to shape the RWE landscape in East Asia and other regions and drive next-generation healthcare.

Renin-Angiotensin Aldosterone System Inhibitors and COVID-19: A Systematic Review and Meta-Analysis Revealing Critical Bias Across a Body of Observational Research

Background Renin-angiotensin aldosterone system (RAAS) inhibitor-COVID-19 studies, observational in design, appear to use biased methods that can distort the interaction between RAAS inhibitor use and COVID-19 risk. This study assessed the extent of bias in that research and reevaluated RAAS inhibitor-COVID-19 associations in studies without critical risk of bias. Methods and Results Searches were performed in MEDLINE, EMBASE, and CINAHL databases (December 1, 2019 to October 21, 2021) identifying studies that compared the risk of infection and/or severe COVID-19 outcomes between those using or not using RAAS inhibitors (ie, angiotensin-converting enzyme inhibitors or angiotensin II type-I receptor blockers). Weighted hazard ratios (HR) and 95% CIs were extracted and pooled in fixed-effects meta-analyses, only from studies without critical risk of bias that assessed severe COVID-19 outcomes. Of 169 relevant studies, 164 had critical risks of bias and were excluded. Ultimately, only two studies presented data relevant to the meta-analysis. In 1 351 633 people with uncomplicated hypertension using a RAAS inhibitor, calcium channel blocker, or thiazide diuretic in monotherapy, the risk of hospitalization (angiotensin-converting enzyme inhibitor: HR, 0.76; 95% CI, 0.66-0.87; P<0.001; angiotensin II type-I receptor blockers: HR, 0.86; 95% CI, 0.77-0.97; P=0.015) and intubation or death (angiotensin-converting enzyme inhibitor: HR, 0.64; 95% CI, 0.48-0.85; P=0.002; angiotensin II type-I receptor blockers: HR, 0.74; 95% CI, 0.58-0.95; P=0.019) with COVID-19 was lower in those using a RAAS inhibitor. However, these protective effects are probably not clinically relevant. Conclusions This study reveals the critical risk of bias that exists across almost an entire body of COVID-19 research, raising an important question: Were research methods and/or peer-review processes temporarily weakened during the surge of COVID-19 research or is this lack of rigor a systemic problem that also exists outside pandemic-based research? Registration URL: www.crd.york.ac.uk/prospero/; Unique identifier: CRD42021237859.

COVID-19 vaccines coverage and effectiveness against SARS-CoV-2 infection among residents in the largest Health Authority of Lazio region (Italy): a population-based cohort study

BACKGROUND

The waning of the protective effect of COVID-19 vaccines and timing of booster doses are debated.

METHODS

Population-based cohort study in the largest Health Authority of Lazio region, Italy, on 946,156 residents aged 12+ (study period: January 1, 2021-January 10, 2022). Vaccine Effectiveness (VE) against any SARS-CoV-2 infection (symptomatic or asymptomatic) was estimated through multivariable negative binomial models using unvaccinated person-time as reference.

RESULTS

The primary vaccination cycle was completed by 81% of residents; of these, 45% received a booster dose. Vaccine coverages were lower for foreigners, deprived areas, families with children aged 0-11, and households of size 1 or 6+. Overall, VE waned from 71% (95% Confidence Interval (CI) 70-73%) 1 month after the second dose to 43% (CI 41-45%) after 4 months and 24% (CI 21-27%) after 6 months, especially in the elderly aged 70+. We observed a prompt restore of VE 15-19 days after the booster dose (69%, CI 67-70%).

CONCLUSIONS

Our results showed effectiveness of a booster dose four months after completion of the primary cycle, and support the recommendation of prioritizing elderly and fragile individuals. The lower vaccine coverage among social disadvantaged subgroups suggests the need of targeted communication and interventions.

Slower Recovery with Early Lopinavir/Ritonavir use in Pediatric COVID-19 Patients: A Retrospective Observational Study

OBJECTIVES

There was initially insufficient understanding regarding suitable pharmacological treatment for pediatric Coronavirus Disease 2019 (COVID-19) patients. Lopinavir-ritonavir (LPV/r) was originally used for the treatment of Human Immunodeficiency Virus-1 (HIV-1) infection. It was also used in patients with severe acute respiratory syndrome (SARS) and Middle East Respiratory Syndrome (MERS) with positive results. Nonetheless, results from recent randomized controlled trials and observational studies on COVID-19 patients were unfavorable. We sought to evaluate the clinical outcomes associated with early treatment with LPV/r for pediatric COVID-19 patients.

STUDY DESIGN

A total of 933 COVID-19 patients aged ≤ 18 years were admitted between 21 January 2020 and 31 January 2021 in Hong Kong. Exposure was receiving LPV/r within the first two days of admission. Time to clinical improvement, hospital discharge, seroconversion and hyperinflammatory syndrome, cumulative costs, and hospital length of stay were assessed. Multivariable Cox proportional hazard and linear models were performed to estimate hazard ratios (HR) and their 95% confidence intervals (CI) of time-to-event and continuous outcomes, respectively.

RESULTS

LPV/r users were associated with longer time to clinical improvement (HR 0.51, 95% CI 0.38-0.70; p < 0.001), hospital discharge (HR 0.51, 95% CI 0.38-0.70; p < 0.001) and seroconversion (HR 0.59, 95% CI 0.43-0.80; p < 0.001) when compared with controls. LPV/r users were also associated with prolonged hospital length of stay (6.99 days, 95% CI 6.23-7.76; p < 0.001) and higher costs at 30 days (US$11,709 vs US$8270; p < 0.001) as opposed to controls.

CONCLUSION

Early treatment with LPV/r for pediatric COVID-19 patients was associated with longer time to clinical improvement. Our study advocates the recommendation against LPV/r use for pediatric patients across age groups.

Assessing and Interpreting Real-World Evidence Studies: Introductory Points for New Reviewers

Nonrandomized real-world evidence (RWE) studies are conducted using healthcare data collected as part of clinical practice. As RWE studies are increasingly considered for regulatory, coverage, and other clinical decision making, nonspecialists will find themselves in the position of assessing the validity of RWE studies, a field that may be less familiar to them. This introductory guide provides conceptual guidance for reviewing RWE studies and is particularly directed at professionals for whom this is new or whose prior experience has primarily been in reviewing randomized controlled trial evidence. We focus on RWE studies that make causal inference, evaluating whether one treatment option is better, worse, or neutral compared to another. Although we provide citations to direct the reader to resources with more details on complex issues, this guide cannot substitute for years of training and expertise in the field.

Evans syndrome in adults: an observational multicenter study

Evans syndrome (ES) is a rare condition, defined as the presence of 2 autoimmune cytopenias, most frequently autoimmune hemolytic anemia and immune thrombocytopenia (ITP) and rarely autoimmune neutropenia. ES can be classified as primary or secondary to various conditions, including lymphoproliferative disorders, other systemic autoimmune diseases, and primary immunodeficiencies, particularly in children. In adult ES, little is known about clinical features, disease associations, and outcomes. In this retrospective international study, we analyzed 116 adult patients followed at 13 European tertiary centers, focusing on treatment requirements, occurrence of complications, and death. ES was secondary to or associated with underlying conditions in 24 cases (21%), mainly other autoimmune diseases and hematologic neoplasms. Bleeding occurred in 42% of patients, mainly low grade and at ITP onset. Almost all patients received first-line treatment (steroids with or without intravenous immunoglobulin), and 23% needed early additional therapy for primary refractoriness. Additional therapy lines included rituximab, splenectomy, immunosuppressants, thrombopoietin receptor agonists, and others, with response rates >80%. However, a remarkable number of relapses occurred, requiring ≥3 therapy lines in 54% of cases. Infections and thrombotic complications occurred in 33% and 21% of patients, respectively, mainly grade ≥3, and correlated with the number of therapy lines. In addition to age, other factors negatively affecting survival were severe anemia at onset and occurrence of relapse, infection, and thrombosis. These data show that adult ES is often severe and marked by a relapsing clinical course and potentially fatal complications, pinpointing the need for high clinical awareness, prompt therapy, and anti-infectious/anti-thrombotic prophylaxis.

The Use of Tocilizumab in Patients with COVID-19: A Systematic Review, Meta-Analysis and Trial Sequential Analysis of Randomized Controlled Studies

Background: Among the several therapeutic options assessed for the treatment of coronavirus disease 2019 (COVID-19), tocilizumab (TCZ), an antagonist of the interleukine-6 receptor, has emerged as a promising therapeutic choice, especially for the severe form of the disease. Proper synthesis of the available randomized clinical trials (RCTs) is needed to inform clinical practice. Methods: A systematic review with a meta-analysis of RCTs investigating the efficacy of TCZ in COVID-19 patients was conducted. PubMed, EMBASE, and the Cochrane COVID-19 Study Register were searched up until 30 April 2021. Results: The database search yielded 2885 records; 11 studies were considered eligible for full-text review, and nine met the inclusion criteria. Overall, 3358 patients composed the TCZ arm, and 3131 the comparator group. The main outcome was all-cause mortality at 28–30 days. Subgroup analyses according to trials’ and patients’ features were performed. A trial sequential analysis (TSA) was also carried out to minimize type I and type II errors. According to the fixed-effect model approach, TCZ was associated with a better survival odds ratio (OR) (0.84; 95% confidence interval (CI): 0.75–0.94; I²: 24% (low heterogeneity)). The result was consistent in the subgroup of severe disease (OR: 0.83; 95% CI: 0.74–0.93; I²: 53% (moderate heterogeneity)). However, the TSA illustrated that the required information size was not met unless the study that was the major source of heterogeneity was omitted. Conclusions: TCZ may represent an important weapon against severe COVID-19. Further studies are needed to consolidate this finding.

Clinical improvement, outcomes, antiviral activity, and costs associated with early treatment with remdesivir for patients with COVID-19

Background

Evidence remains inconclusive on any significant benefits of remdesivir in mild-to-moderate COVID-19 patients. This study explored the disease progression, various clinical outcomes, changes in viral load, and costs associated with early remdesivir treatment among COVID-19 patients.

Methods

A territory-wide retrospective cohort of 10,419 patients with COVID-19 hospitalized from 21st January 2020 to 31st January 2021 in Hong Kong were identified. Early remdesivir users were matched with controls using propensity-score matching in a ratio of up to 1:4. Study outcomes were time to clinical improvement on the WHO clinical progression scale of at least 1 score; hospital discharge; recovery; viral clearance; low viral load; positive IgG antibody; in-hospital death; and composite outcomes of in-hospital death, requiring invasive ventilation or intensive care.

Results

After multiple imputation and propensity-score matching, the median follow-up was 14 days for both remdesivir (n=352) and control (n=1,347) groups. Time to clinical improvement was significantly shorter in the remdesivir group than that of control (hazard ratio (HR)=1.14, 95%CI 1.01-1.29, p=0.038), as well as for achieving low viral load (HR=1.51, 95%CI 1.24-1.83, p<0.001) and positive IgG antibody (HR=1.50, 95%CI 1.31-1.70, p<0.001). Early remdesivir treatment was associated with a lower risk of in-hospital death (HR=0.58, 95%CI 0.34-0.99, p=0.045), in addition to a significantly shorter length of hospital stay (difference -2.56 days, 95%CI -4.86 to -0.26, p=0.029), without increasing the risks of composite outcomes for clinical deterioration.

Conclusions

Early remdesivir treatment could be extended to hospitalized patients presenting with moderate COVID-19 and not requiring oxygen therapy on admission.