scholarly journals The Applicability of N: Ancient Debates and Modern Experimental Design

Healthcare ◽  
2018 ◽  
Vol 6 (3) ◽  
pp. 118 ◽  
Author(s):  
Katherine van Schaik
Keyword(s):  
Observational Studies ◽  
Disease Diagnosis ◽  
Study Data ◽  
Controlled Trials ◽  
Sequencing Data ◽  
Genetic Sequencing ◽  
Randomized Controlled ◽  
Individualized Approach ◽  
Generalized Knowledge ◽  
The Individual

Medicine has always been characterized by a tension between the particular and the general. A clinician is obligated to treat the individual in front of her, yet she accomplishes this task by applying generalized knowledge that describes an abstract average but not necessarily a specific person. Efforts to systematize this process of moving between the particular and the general have led to the development of randomized controlled trials and large observational studies. Inclusion of tens of thousands of people in such studies, it is argued, will enhance the applicability of the data to more individual circumstances. Yet, as genetic sequencing data have become more widely obtained and used, there has been an increased focus on what has been broadly termed “precision medicine”, a highly individualized approach to therapeutics. Moreover, advances in statistical methods have enabled researchers to use N-of-1 study data—traditionally considered too individualized to be broadly applicable—in new ways. This paper contextualizes these apparently modern debates with reference to historical arguments about methods of disease diagnosis and treatment, and earlier physicians’ concerns about the tension between the particular and the general that is intrinsic to medical practice.

scholarly journals Incidence of thrombotic complications in COVID-19

2021 ◽  
Author(s):  
William J. Jenner ◽  
Diana A. Gorog
Keyword(s):  
Intensive Care Unit ◽  
Observational Studies ◽  
Severity Of Illness ◽  
Controlled Trials ◽  
Thrombotic Risk ◽  
Randomized Controlled ◽  
Hospitalised Patients ◽  
High Incidence ◽  
Thrombotic Complications ◽  
Asymptomatic Individuals

AbstractA high incidence of thrombosis in hospitalised patients with COVID-19 was identified early during the pandemic. Accurately quantifying thrombotic risk may assist prognosis and guide appropriate thromboprophylaxis. Observational studies have estimated the rate of thrombosis in both hospitalised and non-hospitalised patients with COVID-19, and how this corresponds to the severity of illness. In this review, we provide an overview of the incidence and prevalence of arterial and venous thrombotic events in patients with COVID-19 and highlight the limitations in the studies to date. Asymptomatic individuals with COVID-19 and those with mild symptoms are at very low risk of thrombotic complications. However, rates of thrombosis are substantially increased in hospitalised patients, and are strikingly high in those patients who are critically-ill requiring treatment on the intensive care unit and especially those requiring extracorporeal membrane oxygenation. Clinicians managing such patients need to be aware of these risks and take appropriate steps with respect to thromboprophylaxis and heightened clinical vigilance. Large prospective observational studies will more accurately quantify thrombotic rate, and randomized controlled trials are currently investigating optimal thromboprophylactic strategies.

scholarly journals High-cited favorable studies for COVID-19 treatments ineffective in large trials

2022 ◽  
Author(s):  
John P.A. Ioannidis
Keyword(s):  
Clinical Trials ◽  
Randomized Controlled Trials ◽  
Clinical Studies ◽  
Observational Studies ◽  
Randomized Trials ◽  
Controlled Trials ◽  
Randomized Controlled ◽  
Wide Dissemination ◽  
Highly Cited Articles ◽  
Highly Cited

Importance. COVID-19 has resulted in massive production, publication and wide dissemination of clinical studies trying to identify effective treatments. However, several widely touted treatments failed to show effectiveness in large well-done randomized controlled trials (RCTs). Objective. To evaluate for COVID-19 treatments that showed no benefits in subsequent large RCTs how many of their most-cited clinical studies had declared favorable results for these interventions. Methods. Scopus (last update December 23, 2021) identified articles on lopinavir-ritonavir, hydroxycholoroquine/azithromycin, remdesivir, convalescent plasma, colchicine or interferon (index interventions) that represented clinical trials and that had received >150 citations. Their conclusions were assessed and correlated with study design features. The ten most recent citations for the most-cited article on each index intervention were examined on whether they were critical to the highly-cited study. Altmetric scores were also obtained. Findings. 40 articles of clinical studies on these index interventions had received >150 citations (7 exceeded 1,000 citations). 20/40 (50%) had favorable conclusions and 4 were equivocal. Highly-cited articles with favorable conclusions were rarely RCTs while those without favorable conclusions were mostly RCTs (3/20 vs 15/20, p=0.0003). Only 1 RCT with favorable conclusions had sample size >160. Citation counts correlated strongly with Altmetric scores, in particular news items. Only 9 (15%) of 60 recent citations to the most highly-cited studies with favorable or equivocal conclusions were critical to the highly-cited study. Conclusion. Many clinical studies with favorable conclusions for largely ineffective COVID-19 treatments are uncritically heavily cited and disseminated. Early observational studies and small randomized trials may cause spurious claims of effectiveness that get perpetuated.

scholarly journals SGLT2 inhibitors and the risk of diabetic ketoacidosis among adults with Type 2 Diabetes: A systematic review and meta-analysis

2021 ◽  
Author(s):  
Michael Colacci ◽  
John Fralick ◽  
Ayodele Odutayo ◽  
Michael Fralick
Keyword(s):  
Diabetic Ketoacidosis ◽  
Observational Studies ◽  
Randomized Trials ◽  
Meta Analysis ◽  
Sglt2 Inhibitor ◽  
Sglt2 Inhibitors ◽  
Controlled Trials ◽  
Absolute Rate ◽  
Randomized Controlled

Importance: The risk of diabetic ketoacidosis (DKA) with sodium-glucose cotransporter-2 (SGLT2) inhibitors is unclear. Objective: To examine the risk of DKA with SGLT2 inhibitors in both observational studies and large clinical trials. Data Sources: Searches of PubMed, EMBASE and CENTRAL (inception to 15 April 2019) without language restrictions; conference proceedings; and reference lists. Study Selection: Randomized controlled trials and observational studies that quantified the rate of diabetic ketoacidosis with an SGLT2 inhibitor in comparison to another diabetes medication or placebo. Data Extraction and Synthesis: Two independent investigators abstracted study data and assessed the quality of evidence. Data were pooled using random effects models with the Hartung-Knapp-Sidik-Jonkman method. Main Outcome and Measures: Absolute event rates and hazard ratios for diabetic ketoacidosis were extracted from each study. Results: Seven randomized trials encompassing 42,375 participants and five cohort studies encompassing 318,636 participants were selected. Among the 7 randomized controlled trials, the absolute rate of DKA among patients randomized to an SGLT2 inhibitor ranged from 0.6 to 2.2 events per 1000 person years. Four randomized trials were included in the meta-analysis, and compared to placebo or comparator medication, SGLT2 inhibitors had a 2.4-fold higher risk of DKA (Relative Risk [RR] = 2.46 [95% CI, 1.16-5.21]; I2 = 0%; P = 0.54). Among the 5 observational studies, the absolute rate of DKA associated with SGLT2 inhibitor use ranged from 0.6 to 4.9 per 1000 person years and a 1.7-fold higher rate of DKA compared to another diabetes medication (RR = 1.74 [95% CI, 1.01-2.93]; I2 = 45%; P = 0.12). Conclusions and Relevance: In adults with type 2 diabetes, SGLT2 inhibitors increase the risk of DKA in both observational studies and large randomized clinical trials. Registration: CRD42019146855 Funding Source: None

scholarly journals Impact of Ramadan Diurnal Intermittent Fasting on Hypoglycemic Events in Patients With Type 2 Diabetes: A Systematic Review of Randomized Controlled Trials and Observational Studies

2021 ◽  
Vol 12 ◽  
Author(s):  
Dana Abdelrahim ◽  
MoezAlIslam E. Faris ◽  
Mohamed Hassanein ◽  
Ayman Z. Shakir ◽  
Ayesha M. Yusuf ◽  
...  
Keyword(s):  
Systematic Review ◽  
Type 2 Diabetes ◽  
Randomized Controlled Trials ◽  
Observational Studies ◽  
Dietary Behaviors ◽  
Controlled Trials ◽  
Ramadan Fasting ◽  
Randomized Controlled ◽  
The Impact

Ramadan is the 9th month of the lunar calendar during which Muslims abstain from food and drink between dawn and sunset for 30 consecutive days. Ramadan fasting is observed by all healthy Muslim adults, as well many Muslims with type 2 diabetes (T2DM). Hypoglycemic events (HE) are a serious complication associated with diabetes management and are associated with increased cardiovascular disease risk. Conflicting results have been reported concerning the incidence of HE among people with T2DM observing Ramadan fasting. This review summarizes available scientific evidence on the occurrence of HE and the effects of different moderators on the incidence of HE among patients with T2DM during Ramadan. We conducted a systematic review of available observational studies and randomized controlled trials (RCTs) for patients with T2DM who fasted during Ramadan, with HE as the primary outcome. Ten databases were searched for relevant studies from inception until October 31, 2020. In total, 68 studies (35 RCTs and 33 observational studies) met the inclusion criteria. Non-sulfonylureas hypoglycemic medications showed superior effects in lowering the incidence of HE over sulfonylureas hypoglycemic medications. Variable moderators were associated with experiencing HE during Ramadan in both observational studies and RCTs, including sex, geographical location, body anthropometric indicators, season, dietary behaviors, fasting duration, time since diagnosis, and pre-fasting education. This comprehensive systematic review covered the largest number of observational and clinical studies investigating the impact of Ramadan on HE among patients with T2DM. The study highlights the significance of different moderators that influence the effect of Ramadan fasting on HE, including dietary behaviors, fasting time duration, sex, season, country, pre-fasting education, age, and time since diagnosis. The study also highlighted the impact of different hypoglycemic medications on HE and noted the superiority of non-sulfonylureas over sulfonylureas hypoglycemic medications in lowering the risk for hypoglycemia in people with T2DM during Ramadan fasting.

Observational studies: going beyond the boundaries of randomized controlled trials

2010 ◽  
Vol 88 ◽  
pp. S3-S9 ◽  
Author(s):  
Wenying Yang ◽  
Alexey Zilov ◽  
Pradana Soewondo ◽  
Ole Molskov Bech ◽  
Fawzia Sekkal ◽  
...  
Keyword(s):  
Randomized Controlled Trials ◽  
Observational Studies ◽  
Controlled Trials ◽  
Randomized Controlled

Mechanical Thromboprophylaxis in Critically Ill Patients: A Systematic Review and Meta-Analysis

2006 ◽  
Vol 15 (4) ◽  
pp. 402-412 ◽  
Author(s):  
Anthony Limpus ◽  
Wendy Chaboyer ◽  
Ellen McDonald ◽  
Lukman Thalib
Keyword(s):  
Intensive Care ◽  
Randomized Controlled Trials ◽  
Observational Studies ◽  
Meta Analysis ◽  
Controlled Trials ◽  
Trauma Patients ◽  
Intensive Care Patients ◽  
Randomized Controlled ◽  
Confounding Variables

• Objective To systematically review the randomized trials, observational studies, and survey evidence on compression and pneumatic devices for thromboprophylaxis in intensive care patients. • Methods Published studies on the use of compression and pneumatic devices in intensive care patients were assessed. A meta-analysis was conducted by using the randomized controlled trials. • Results A total of 21 relevant studies (5 randomized controlled trials, 13 observational studies, and 3 surveys) were found. A total of 811 patients were randomized in the 5 randomized controlled trials; 3421 patients participated in the observational studies. Trauma patients only were enrolled in 4 randomized controlled trials and 4 observational studies. Meta-analysis of 2 randomized controlled trials with similar populations and outcomes revealed that use of compression and pneumatic devices did not reduce the incidence of venous thromboembolism. The pooled risk ratio was 2.37, indicative of favoring the control over the intervention in reducing the deep venous thrombosis; however, the 95% CI of 0.57 to 9.90 indicated no significant differences between the intervention and the control. A range of methodological issues, including bias and confounding variables, make meaningful interpretation of the observational studies difficult. • Conclusions The limited evidence suggests that use of compressive and pneumatic devices yields results not significantly different from results obtained with no treatment or use of low-molecular-weight heparin. Until large randomized controlled trials are conducted, the role of mechanical approaches to thromboprophylaxis for intensive care patients remains uncertain.

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