<h4>Background</h4>Guidelines recommending regular physical activity in pregnancy for improving pregnancy outcomes are informed by published meta-analyses. Inclusion of randomised trials of poor methodological quality may bias effect estimates.<h4>Objectives</h4>To assess the validity of these recommendations by focusing on trial quality.<h4>Search strategy</h4>Systematic search of PubMed, PubMed Central, Ovid Medline, Embase, Cochrane Central Register of Controlled Trials, and CINAHL from inception to 14 December 2023.<h4>Selection criteria</h4>Randomised trials evaluating an antenatal physical activity intervention alone, compared with no such intervention.<h4>Data collection and analysis</h4>Trial quality was assessed using the Cochrane Risk of Bias tool. Independent of this, studies were grouped based on degree of deviation from the intention to treat principle. Sequential meta-analysis was performed in which greater degrees of potential bias were allowed. Between intervention group comparisons used, relative risks or mean differences with 95% confidence intervals for dichotomous outcomes and continuous outcomes, respectively.<h4>Main results</h4>Overall, the quality of trial reporting was low. Only 5 trials (12.5%) were performed and analysed in keeping with the intention to treat principle. When considering only those trials performed rigorously, there was no evidence that antenatal physical activity improves pregnancy outcomes or limits gestational weight gain (WMD -0.60 kg; 95% CI -2.17, 0.98 WMD -0.60 kg; 95% CI -2.17, 0.98).<h4>Conclusions</h4>When considering only trials at no/negligible risk of bias, antenatal physical activity interventions were not associated with improved pregnancy outcomes. Most trials were not methodologically rigorous. Incorporation of such meta-analyses into pregnancy care guidelines may result in inaccurate recommendations. 379 blackwellopen Bjog BJOG PMC11969922 11969922 11969922 39895455 10.1111/1471-0528.18084 Antenatal Physical Activity Interventions and Pregnancy Outcomes: A Systematic Review and Meta‐Analysis With a Focus on Trial Quality Poprzeczny Amanda J 1 2 ✉ Deussen Andrea R 1 Mitchell Megan 1 Slade Laura 1 2 Louise Jennie 3 4 Dodd Jodie M 1 2 1 Department of Obstetrics and Gynaecology, The Robinson Research Institute, The University of Adelaide, Adelaide, South Australia, Australia 2 Women's and Babies Division, Department of Obstetrics and Gynaecology, The Women's and Children's Hospital, Adelaide, South Australia, Australia 3 Women's and Children's Hospital Research Centre, Adelaide, South Australia, Australia 4 Biostatistics Unit, South Australia Health and Medical Research Institute, Adelaide, South Australia, Australia * Correspondence: Amanda J. Further details are provided in Table 1 . TABLE 1 Classification of degree of potential for bias based on departures from the intention‐to‐treat population. When incorporating all trials, including those with significant potential for bias, there was no significant effect of physical activity interventions on infant birthweight (31 trials; 5633 participants; WMD −26.17 g; 95% CI −56.73, 4.39; 95% prediction interval −118.42, 66.08; I 2 = 26.87; τ 2 = 1791.49) (Table 3 ). TABLE 3 Effect of intervention on infant and maternal outcomes. a Unable to calculate due to small number of studies. 3.4.2. Meta‐Analysis 2: Gestational Diabetes Mellitus A total of 16 trials (40%) reported GDM, with data available from 13 trials (32.5%). Only 1 trial (2.5%) was considered to have no/negligible potential for bias, with no significant effect of the intervention on GDM (1 trial; 48 participants; RR 0.60; 95% CI 0.16, 2.23) (Table 3 ). Inclusion of trials at progressively increasing potential for bias shifted the estimate of effect further from the null, with progressively increasing heterogeneity (Figure S2 ). The effect of sequential incorporation of trials at increasing potential for bias on the effect estimate is demonstrated in Figure S2 . Inclusion of all trials demonstrated no significant effect of physical activity interventions on preeclampsia (6 trials; 1920 participants; RR 0.89; 95% CI 0.55, 1.44; 95% prediction interval 0.45, 1.76; I 2 = 0.00; τ 2 = 0.00) (Table 3 ). 3.4.4. Meta‐Analysis 4: LSCS Overall, 26 studies (65.0%) reported caesarean birth, with 23 (57.5%) contributing data. Meta‐Analysis 5: Gestational Weight Gain A total of 28 trials (70%) reported gestational weight gain, with 22 trials (55.0%) contributing data for meta‐analysis. When considering trials at no or negligible risk of bias, there was no significant effect of the intervention on gestational weight gain (two trials; 113 participants; WMD −0.60 kg; 95% CI −2.17, 0.98) (Table 3 ). Incorporating data from trials at increasing potential for bias resulted in shifting of the estimate of effect further from the null, with progressively increasing heterogeneity (Figure S2 ). When incorporating all trials, there was a modest significant effect on gestational weight gain (22 trials; 4111 participants; WMD −1.22 kg; The authors have no conflicts of interest to declare. Supporting information Figure S1. Search strategy for Ovid MEDLINE database. Figure S2 . Effect of intervention and risk of bias on maternal and infant outcomes. Acknowledgements Open access publishing facilitated by The University of Adelaide, as part of the Wiley ‐ The University of Adelaide agreement via the Council of Australian University Librarians. Funding: This work was supported by National Health and Medical Research Council. Data Availability Statement The data presented in this analysis are available for discussion and review with the authors. References Associated Data Supplementary Materials Figure S1. Search strategy for Ovid MEDLINE database. Figure S2 . Effect of intervention and risk of bias on maternal and infant outcomes. Data Availability Statement The data presented in this analysis are available for discussion and review with the authors.

Background: Medical studies are more likely to report favorable findings when a conflict of interest is declared. We aim to quantify and determine the effect of author disclosure of conflict of interest on scientific reporting. Methods: Abstracts from an international spine research meeting (North American Spine Society 2010) were selected that specifically evaluated a device, biologic, or proprietary procedure. They were then made anonymous to reviewers. An item of interest was established in each of the abstracts in order to standardize evaluation. Next, three blinded reviewers independently PLoS One PLoS ONE 440 plosone plos PLoS ONE 1932-6203 PLOS PMC3432133 PMC3432133.1 3432133 3432133 22952956 10.1371/journal.pone.0044327 PONE-D-12-18136 1 Research Article Medicine Drugs and Devices Medical Devices Non-Clinical Medicine Medical Ethics Socioeconomic Aspects of Health Surgery Neurosurgery Science Policy Research Assessment Publication Practices Research Reporting Guidelines Research Funding Corporate Funding of Science Conflict of Interest in Spine Research Reporting Conflict of Interest in Spine Research Walcott Brian P. * Sheth Sameer A. Nahed Brian V. Coumans Jean-Valery Department of Neurosurgery, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, United States of America Gagnier Joel Joseph Editor University of Michigan, United States of America * E-mail: walcott.brian@mgh.harvard.edu Competing Interests: The authors have declared that no competing interests exist. Conceived and designed the experiments: BPW JVC. Performed the experiments: BPW SAS BVN JVC. Analyzed the data: BPW JVC. Contributed reagents/materials/analysis tools: JVC. Wrote the paper: BPW SAS BVN JVC. Results Of the 344 total abstracts, 76 met inclusion criteria. In 79%, a related conflict of interest was reported. The amount of the disclosure was incompletely reported in 30% of cases. Where available, it averaged a cumulative minimum of $219,634 USD per abstract. The results of the abstracts were judged to be favorable, neutral, and unfavorable in 63%, 32% and 5% of abstracts, respectively. There was no correlation between the presence of a related disclosure and the findings of the studies (p = 0.81), although interpretation of this is limited by a small sample size and an overall apparent bias to report favorable studies. There is a societal and patient centered expectation that the treating provider is free from these conflicts when rendering decisions about medical care. Paradoxically, there is also the realization that in the current healthcare delivery system, potential conflicts are unavoidable for the most part. Indeed, there are many beneficial aspects of commercial alliance, including research support, clinical product support, and innovation. Therefore, public transparency is expected to exist in order to improve the impartiality of a de facto impartial arrangement. New legislation, such as the Physician Payments Sunshine Act, has recently been enacted to improve transparency of these physician-industry relationships through mandatory public disclosure. [1] For the spine surgeon in particular, affiliation with industry raises concerns for impartiality and conflict of interest. Medical devices and biologics are rapidly growing staples in the practices of many spine surgeons and have significant costs at both the individual and national level. Finally, the 2010 NASS annual meeting disclosure index (release date May 10, 2010) was used to tabulate the minimum US dollar value attributable to related royalties, consulting, speaking & travel arrangements, scientific advisory board work, and grants or research support, creating a matrix with the abstract authorship information. [16] Levels of financial association were previously categorized by the NASS as (A) $100 to 1000, (B) $1001 to 10,000, (C) $10,001 to 25,000, (D) $25,001 to 50,000, (E) $50,001 to 100,000, (F) $100,001 to 500,000, (G) $500,001 to 1,000,000, (H) $1,000,001 to 2,500,000, and (I) greater than $2,500,000. While much has been written on the potential influence of conflict of interest on medical and scientific work, our study is the first to use quantitative analysis to analyze actual dollar amount estimates of related financial conflicts of interest (self reported). Our analysis failed to find a correlation between the perceived findings of the abstract and the presence of a potential conflict of interest. Additionally, because the choice of words and the tone of the abstract can lead to a perception of bias, we attempted to increase the reliability of our findings by asking each independent, blinded reviewer to guess whether a conflict of interest existed based on the tone of the abstract. In this study, we report that despite a high percentage of disclosed conflicts of interest for research studies summating to a significant amount of money, no apparent influence on reporting of their outcome was found. Physicians and scientists are held to the highest ethical standard of maintaining independence in decision making and data analysis. Speaking honoraria, consulting contracts, and royalty payments, must never distort clinical care and research integrity. Studies have demonstrated that conflict of interest may have conscious or unconscious effects that lead to the promotion of devices or off-label use of devices. [18] , [19] Also known at the “winner’s curse”, the current system of biomedical literature evaluation, publication, and dissemination distorts the reality of scientific research via a very strong publication bias in favor of positive results. [20] , [21] With a bias towards positive studies, it is difficult to assess the influence of conflict of interest on study outcome when the majority of studies presented in an overall small sample size are favorable. Secondary to this power limitation, a type II error cannot be excluded.

Interactions between drug companies and medical students may affect evidence-based medical practice and patient safety. The aim of this study was to assess drug company–medical student interactions in a medical faculty where limited specific national or institutional regulations apply between drug companies and medical students. The objectives of the study were to determine the exposure and attitudes of final year medical students in terms of drug company–medical student and physician interactions, to identify factors affecting those attitudes and to provide data for policymakers working on th These regulations will inevitably affect students to some extent, even if they make no specific provisions for them. In addition, the universities at which the research was performed have no policies for regulating interactions between drug companies and students. Most studies of drug company-physician and drug company-student interactions have been conducted in the developed world [ 19 ]. More recently, however, there have been many studies of exposure on the part of physicians and medical students to drug company interactions in the developing world. The purpose of this research was to determine the extent of exposure to drug companies, the attitudes concerning drug company interactions among final year medical students, to determine whether exposure to drug companies (exposure to drug company representatives or receiving promotional products such as drug advertisement brochures, meals, small gifts, free drug samples, or sponsored travel) and prior rational prescription training affects their attitudes and to provide data for policy makers working on the regulation of interactions between drug companies and medical students in the short and long terms. Those students who agreed that physicians are affected also exhibited significantly higher agreement that their own future prescription writing behavior might be affected (60.7 vs 23.9%, p<0.001). b. Skepticism toward accepting drug company sponsored gifts and products In this research, 33.1% (51/154) of students agreed that a medical student should never accept any gift from a drug company. However, 57.1% (88/154) and 72.7% (112/154) of students saw nothing wrong in accepting small gifts or attending drug company sponsored scientific meetings, respectively. c. Accepted drug advertisement brochure Accepted small, non-educational gifts Accepted meal Accepted free drug sample Accepted textbook At least once/Never P At least once/Never P At least once/Never P At least once/Never P At least once/Never P Influence of drug companies on prescription and perception of own knowledge of drugs Interactions influence physicians’ prescription preferences (Disagreement or undecided) 29.0/26.5 0.778 28.6/28.6 0.980 27.5/28.6 0.888 26.4/26.2 0.977 31.3/28.8 1.000 I think that interactions influence resident physicians’ prescription preferences (Disagreement or undecided) 30.6/35.3 0.605 30.3/32.1 0.845 25.0/36.9 0.149 25.9/33.3 0.356 31.3/32.8 0.903 The interactions that I was exposed to may influence my future prescription preferences (Disagreement or undecided) 48.1/58.8 0.278 48.7/53.6 0.645 44.2/56.0 0.184 46.3/51.2 0.575 50.0/51.3 0.925 I possess sufficient knowledge about drugs to function as a general practitioner (Agreement) 31.5/26.5 0.579 29.4/32.1 0.776 30.8/29.8 0.901 35.2/26.2 0.259 56.3/26.1 0.019 My level of medical knowledge is sufficient to assess the information in drug advertisement brochures (Agreement) 70.1/41.2 0.002 63.0/51.9 0.283 67.3/61.4 0.491 63.0/61.4 0.858 56.3/65.3 0.481 Skepticism towards accepting drug sponsored gifts and products A public employee should never accept gifts (Agreement) 54.2/64.7 0.282 57.1/53.6 0.732 59.6/54.8 0.579 59.3/57.1 0.806 56.3/57.1 0.946 A medical student should never accept a gift from a drug company (Agreement) 28.7/47.1 0.047 27.7/50.0 0.023 28.8/34.5 0.492 31.5/34.5 0.711 37.5/32.8 0.706 There is nothing wrong in accepting small gifts as reminders, such as pens, key rings, memory sticks or bags (Disagreement or undecided) 37.0/61.8 0.011 41.2/50.0 0.396 32.7/50.0 0.048 38.9/47.6 0.314 50.0/43.7 0.634 A physician should not accept any gift from a drug company (Agreement) 38.0/52.9 0.122 42.0/42.9 0.935 48.1/38.1 0.252 42.6/42.9 0.976 56.3/41.2 0.253 I see nothing wrong in physicians attending scientific meetings sponsored by drug companies (Disagreement or undecided) 25.9/32.4 0.464 26.1/35.7 0.305 17.3/33.3 0.041 27.8/29.8 0.802 31.3/26.9 0.767 Skepticism towards drug company–students–physician interactions other than accepting gifts Interactions are an important source of information (Disagreement or undecided) 65.7/61.8 0.672 63.0/67.9 0.632 65.4/63.1 0.787 72.2/59.5 0.128 56.3/64.7 0.509 I trust the information in drug advertisement brochures (Disagreement or undecided) 84.9/82.4 0.722 82.9/85.7 1.000 82.7/85.4 0.678 83.0/84.3 0.839 80.0/86.4 0.450 The information provided during interactions is impartial (Agreement) 8.5/17.6 0.133 9.3/14.3 Acceptance of drug company sponsored gifts and products (drug advertisement brochures, small, non-educational gifts, meals, free drug samples, textbooks) Students who had accepted drug advertisement brochures at least once expressed significantly higher agreement with the statement “My level of medical knowledge is sufficient to assess the information in drug advertisement brochures” than students who had never accepted them (4.9[1.8–13.6], p = 0.002). The recall bias might be greater for the questions about the first exposure time, the first exposure site and types of exposures. In addition, although our findings replicate those from many other international studies, our study’s findings represent the results from a single university and therefore a relatively low number of students could be included. In conclusion, the interactions between final year medical students and drug companies are common. These interactions may affect the students’ attitudes.