Lies, damned lies and statistics: Clinical importance versus statistical significance in research

Long-Term Neurological Sequelae Among Severe COVID-19 Patients: A Systematic Review and Meta-Analysis

Few studies have thoroughly evaluated the neuro-invasive effect of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, which may contribute to a wide range of sequelae from mild long-term effects like headaches and fatigue to severe events like stroke and arrhythmias. Our study aimed to evaluate the long-term neurological effects of coronavirus disease 2019 (COVID-19) among patients discharged from the hospital.

In this systematic review and meta-analysis, we assessed the long-term neurocognitive effects of COVID-19. Post-COVID-19 neurological sequelae were defined as persistent symptoms of headache, fatigue, myalgia, anosmia, dysgeusia, sleep disturbance, issues with concentration, post-traumatic stress disorder (PTSD), suicidality, and depression long after the acute phase of COVID-19. Data from observational studies describing post-COVID-19 neurocognitive sequelae and severity of COVID-19 from September 1, 2019, to the present were extracted following the Meta-analysis of Observational Studies in Epidemiology (MOOSE) guidelines and Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) protocol with a consensus of three independent reviewers. A systematic review was performed for qualitative evaluation and a meta-analysis was performed for quantitative analysis by calculating log odds of COVID-19 neurocognitive sequelae. The odds ratio (OR) and 95% confidence interval (CI) were obtained and forest plots were created using random effects models. 

We found seven studies, out of which three were used for quantitative synthesis of evidence. Of the 3,304 post-COVID-19 patients identified, 50.27% were male with a mean age of 56 years; 20.20% had post-COVID-19 symptoms more than two weeks after the acute phase of infection. Among persistence symptoms, neurocognitive symptoms like headache (27.8%), fatigue (26.7%), myalgia (23.14%), anosmia (22.8%), dysgeusia (12.1%), sleep disturbance (63.1%), confusion (32.6%), difficulty to concentrate (22%), and psychiatric symptoms like PTSD (31%), feeling depressed (20%), and suicidality (2%) had a higher prevalence. In meta-analysis, COVID-19 patients with severe symptoms had higher odds of headache (pooled OR: 4.53; 95% CI: 2.37-8.65; p<0.00001; I²: 0%) and myalgia (pooled OR: 3.36; 95% CI: 2.71-4.17; p<0.00001; I²: 0%). Anosmia, fatigue, and dysgeusia had higher but non-significant odds following COVID-19.

Although we had sufficient data for headache and fatigue to identify higher rates and associations following COVID-19, we could not establish relationships with other post-COVID-19 neurocognitive séqueles. Long-term follow-up may mitigate the neurocognitive effects among COVID-19 patients as these symptoms are also associated with a poor quality of life.

The Medical Information Scientific Process: Define, Research, Evaluate, Synthesize, and Share (DRESS)

Medical information (MI) professionals are primarily responsible for researching and responding to unsolicited requests for information on their company’s product(s). In an effort to set a standard for quality, the Pharma Collaboration for Transparent Medical Information (phactMI) created a code of practice for the provision of medical information to healthcare professionals. This code introduced the term “MI science skills” to describe the expertise required to perform the duties of an MI professional. These skills can be summarized by the acronym DRESS. In order to effectively and efficiently respond to an unsolicited request for information, the MI professional essentially follows five steps: define the question, research the topic, evaluate the evidence, synthesize a response, and share the answer. As this approach mirrors the scientific process for data generation, MI scientist may be a more apt description for this role. This paper explains the rationale behind the term MI scientist and the skills associated with each component of the DRESS approach.

What Do We Really Know about the Effectiveness of Glaucoma Interventions?: An Overview of Systematic Reviews

PURPOSE

To identify systematic reviews of interventions for glaucoma conditions and to assess their reliability, thereby generating a list of potentially reliable reviews for updating glaucoma practice guidelines.

DESIGN

Cross-sectional study.

PARTICIPANTS

Systematic reviews of interventions for glaucoma conditions.

METHODS

We used a database of systematic reviews and meta-analyses in vision research and eye care maintained by the Cochrane Eyes and Vision United States Satellite. We examined all Cochrane systematic reviews of interventions for glaucoma conditions published before August 7, 2019, and all non-Cochrane systematic reviews of interventions for glaucoma conditions published between January 1, 2014, and August 7, 2019.

MAIN OUTCOME MEASURES

We assessed eligible reviews for reliability, extracted characteristics, and summarized key findings from reviews classified as reliable.

RESULTS

Of the 4451 systematic reviews in eyes and vision identified, 129 met our eligibility criteria and were assessed for reliability. Of these, we classified 49 (38%) as reliable. We found open-angle glaucoma (22/49) to be the condition with the most reviews and medical management (17/49) and intraocular pressure (IOP; 43/49) to be the most common interventions and outcomes studied. Most reviews found a high degree of uncertainty in the evidence, which hinders the possibility of making strong recommendations in guidelines. These reviews found high-certainty evidence about a few topics: reducing IOP helps to prevent glaucoma and its progression, prostaglandin analogs are the most effective medical treatment for lowering IOP, laser trabeculoplasty is as effective as medical treatment as a first-line therapy in controlling IOP, the use of IOP-lowering medications in the perioperative or postoperative periods to accompany laser (e.g., trabeculoplasty) reduces the risk of postoperative IOP spikes, conventional surgery (i.e., trabeculectomy) is more effective than medications in reducing IOP, and antimetabolites and β-radiation improve IOP control after trabeculectomy. The evidence is weak regarding the effectiveness of minimally invasive glaucoma surgeries.

CONCLUSIONS

Most systematic reviews evaluating interventions for glaucoma are of poor reliability. Even among those that may be considered reliable, important limitations exist in the value of information because of the uncertainty of the evidence as well as small and sometimes unimportant clinical differences between interventions.

Lies, Damn Lies, and Bad Statistics?

A wide spectrum of research such as experimental, randomized trials, cohort or epidemiological studies, technical or control case reports, systematic reviews, and meta-analyses has resulted in a huge amount of publications. These studies and publications may be subject to errors due to poor application of statistical tests, which can lead to misinformation, misinterpretation, and erroneous conclusions, sometimes even considered as lies. In this article, some ideas about this issue are discussed in order to adopt new directions in the future and thus avoid lies and bad statistics.

The influence of the rs1137101 genotypes of leptin receptor gene on the demographic and metabolic profile of normal Saudi females and those suffering from polycystic ovarian syndrome

BACKGROUND

Polycystic ovarian syndrome (PCOS) is of frequent occurrence in Saudi females and is often associated with obesity, insulin resistance, hypogonadotropic hypogonadism, and infertility. Since these features are also associated with leptin receptor (LEP-R) deficiency, several studies have attempted to link LEP-R gene polymorphisms to PCOS.

METHODS

The purpose of this study is to assess the possible association of LEP-R gene polymorphism (rs1137101) with the main obesity-linked metabolic parameters in Saudi female patients affected by PCOS. A cohort of 122 Saudi female subjects, attending the outpatient's clinics at Makkah, Saudi Arabia and diagnosed with PCOS was investigated. Metabolic parameters in serum samples, including lipidogram, glucose, leptin, ghrelin and insulin and obesity markers (BMI, W/H ratio, HOMA) were assayed and compared with values from 130 healthy female volunteers (controls). The genotyping of rs1137101 polymorphism in the leptin receptor gene by amplification (PCR) followed by DNA sequencing, was conducted in both groups (PCOS and controls).

RESULTS

Waist/hip ratio (W/H ratio), leptin serum levels and triglycerides appeared to be associated with PCOS but, aside from W/H ratio (AA s GG p = 0.009), this association also occurred for controls. No significant association in the leptin gene polymorphic locus rs1137101 with PCOS was seen in the results of the present study. In the control group, BMI, W/H ratio, leptin, Insulin, and HOMA-IR were significantly higher in the GG genotype compared to AA.

CONCLUSION

Despite previous suggestion about a relationship between rs1137101, serum leptin levels, and PCOS, our studies do not show any statistical association and further investigations; possibly by also evaluating obese patients should be needed to elucidate this issue better.

A randomized controlled trial on the effect of a silver carboxymethylcellulose dressing on surgical site infections after breast cancer surgery

BACKGROUND

The incidence of surgical site infections (SSIs) after breast cancer surgery is relatively high; ranging from 3 to 19%. The role of wound dressings in the prevention of SSI after breast cancer surgery is unclear. This study compares a silver carboxymethylcellulose dressing (AQUACEL Ag Surgical (Aquacel) with standard wound dressing in SSI rate after breast cancer surgery.

PATIENTS AND METHODS

A single-centre randomized controlled trial among women ≥18 years, diagnosed with breast cancer, undergoing breast conserving or ablative surgery, was conducted in a combined in and outpatient setting. The intervention was the use of Aquacel, compared with standard gauze dressing. Primary outcome measure was SSI following CDC criteria.

RESULTS

A total of 230 patients were analysed: 106 in the Aquacel group and 124 controls. Seven patients (6.6%) developed SSI in the Aquacel group and 16 patients (12.9%) in the control group (RR 0.51 [95% Confidence Interval (CI): 0.22-1.20]; p = 0.112; adjusted OR 0.49 [0.19-1.25] p = 0.135)). Unplanned exploratory subgroup analysis of breast conserving surgery patients showed that SSI rate was 1/56 (1.8%) in the Aquacel group vs. 7/65 (10.8%) in controls; adjusted OR 0.15 [0.02-1.31] p = 0.087. The Aquacel group showed better patient satisfaction (median 8 vs. 7 on a Numerical Rating Scale, p = 0.006), fewer dressing changes within 48 hours(adjusted OR 0.12 [0.05-0.27] p<0.001), fewer re-operations (0% vs. 3.2%, p = 0.062), and lower mean wound-related treatment costs, both in a high (€265.42 (SD = 908) vs. €470.65 (SD = 1223) [p<0.001]) and low (€59.12 (SD = 129) vs. €67.55 (SD = 172) [p<0.001]) attributable costs of SSI model.

CONCLUSION

In this randomized controlled trial in women undergoing surgery for breast cancer, the use of AQUACEL Ag Surgical wound dressing did not significantly reduce the occurrence of SSIs compared to standard gauze dressing. The use of Aquacel resulted in significantly improved patient satisfaction, reduced dressing changes and reduced wound-related costs.

TRIAL REGISTRATION

www.trialregister.nl: NTR5840.