Missing data frequency and correlates in two randomized surgical trials for urinary incontinence in women

Introduction and hypothesis

Missing data is frequently observed in clinical trials; high rates of missing data may jeopardize trial outcome validity.

Purpose

We determined the rates of missing data over time, by type of data collected and compared demographic and clinical factors associated with missing data among women who participated in two large randomized clinical trials of surgery for stress urinary incontinence, the Stress Incontinence Surgical Treatment Efficacy Trial (SISTEr) and the Trial of Midurethral Sling (TOMUS).

Methods

The proportions of subjects who attended and missed each follow-up visit were calculated. The chi-squared test, Fisher’s exact test and t test were used to compare women with and without missing data, as well as the completeness of the data for each component of the composite primary outcome.

Results

Data completeness for the primary outcome computation in the TOMUS trial (62.3 %) was nearly double that in the SISTEr trial (35.7 %). The follow-up visit attendance rate decreased over time. A higher proportion of subjects attended all follow-up visits in the TOMUS trial and overall there were fewer missing data for the period that included the primary outcome assessment at 12 months. The highest levels of complete data for the composite outcome variables were for the symptoms questionnaire (SISTEr 100 %, TOMUS 99.8 %) and the urinary stress test (SISTEr 96.1 %, TOMUS 96.7 %). In both studies, the pad test was associated with the lowest levels of complete data (SISTEr 85.1 %, TOMUS 88.3 %) and approximately one in ten subjects had incomplete voiding diaries at the time of primary outcome assessment. Generally, in both studies, a higher proportion of younger subjects had missing data. This analysis lacked a patient perspective as to the reasons for missing data that could have provided additional information on subject burden, motivations for adherence and study design. In addition, we were unable to compare the effects of the different primary outcome assessment time-points in an identically designed trial.

Conclusions

Missing visits and data increased with time. Questionnaire data and physical outcome data (urinary stress test) that could be assessed during a visit were least prone to missing data, whereas data for variables that required subject effort while away from the research team (pad test, voiding diary) were more likely to be missing. Older subjects were more likely to provide complete data.

     

Improving Trauma Care in India: the Potential Role of the Rural Trauma Team Development Course (RTTDC)

The Rural Trauma Team Development Course (RTTDC) was devised to optimize trauma resuscitation training in under-resourced rural institutions. This program appears ideal for India because of its dense traffic, large population, and high frequency of rural trauma. We report on the feasibility and desirability of introducing RTTDC in India. An instructor course for 20 faculties and a provider course for 23 were conducted in New Delhi, India. The courses were evaluated by multiple choice question (MCQ) performance, by rating the modules on a three-point scale (1 = very relevant, 2 = relevant, and 3 = not relevant) for communication skills, principles of performance improvement and patient safety (PIPS), and clinical scenarios. Evaluation questionnaires including desirability of promulgation in India were completed using a five-point Likert Scale (1 = strongly agree, 2 = agree, 3 = neutral, 4 = disagree, and 5 = strongly disagree). Overall written comments were also provided. Both faculty and providers improved post-course MCQ scores (p?<?0.05) with lower scores in the provider group. Seventy-eight percent faculty and 74 % providers rated the communication module very relevant. PIPS was rated very relevant by 72 % faculty and 65 % providers. There were over 150 comments, generally positive with over 90 % of both faculty and providers rating strongly agree to agree that the course be promulgated widely in India. The RTTDC including plans for promulgation was enthusiastically received in India, and its potential for improving trauma care including communication skills and PIPS appears excellent.     

Magnetic resonance imaging of peripheral joints in rheumatic diseases

The need for better methods than the conventional clinical, biochemical and radiographical examinations in the management of inflammatory joint diseases is evident, since these methods are not sensitive or specific to early pathologies and subtle changes. Magnetic resonance imaging (MRI) offers improved sensitivity to early inflammatory and destructive changes in peripheral joints in rheumatoid arthritis (RA) and, even though less well documented, in other inflammatory joint diseases. Good evidence is available that MRI bone erosions represent true bone abnormalities and are predictors of radiographical outcome in RA. Similarly, there is solid evidence for MRI synovitis representing true synovial inflammation and being of considerable practical, clinical and radiological significance in RA. Describing the encouraging current knowledge regarding MRI for diagnosis, monitoring and prognosis, this chapter discusses the potential for the use of MRI in the clinical management of patients with suspected and diagnosed inflammatory joint diseases, as well as research priorities and clinical situations where the use of MRI could be suggested.     

Hemochromatosis mutations in the general population: iron overload progression rate

The progression rate of iron overload in hereditary hemochromatosis in individuals in the general population is unknown. We therefore examined in the general population iron overload progression rate in C282Y homozygotes. Using a cohort study of the Danish general population, The Copenhagen City Heart Study, we genotyped 9174 individuals. The 23 C282Y homozygotes identified were matched to 2 subjects each of 5 other HFE genotypes with respect to sex, age, and alcohol consumption. As a function of biologic age, transferrin saturation increased from 50% to 70% from 25 to 85 years of age and from 70% to 80% from 35 to 80 years of age in female and male C282Y homozygotes, respectively. Equivalently, ferritin levels increased from 100 to 500 µg/L and decreased from 800 to 400 µg/L in female and male C282Y homozygotes. As a function of 25 years follow-up irrespective of age, transferrin saturation and ferritin levels increased slightly in male and female C282Y homozygotes. None of the C282Y homozygotes developed clinically overt hemochromatosis. In conclusion, individuals in the general population with C282Y homozygosity at most demonstrate modest increases in transferrin saturation and ferritin levels, and clinically overt hemochromatosis is rare. Therefore, C282Y homozygotes identified during population screening, and not because of clinically overt hemochromatosis, at most need to be screened for manifestations of hemochromatosis every 10 to 20 years. (Blood. 2004;103: 2914-2919)      

A potent small molecule inhibits polyglutamine aggregation in Huntington's disease neurons and suppresses neurodegeneration in vivo

Polyglutamine (polyQ) disorders, including Huntington's disease (HD), are caused by expansion of polyQ-encoding repeats within otherwise unrelated gene products. In polyQ diseases, the pathology and death of affected neurons are associated with the accumulation of mutant proteins in insoluble aggregates. Several studies implicate polyQ-dependent aggregation as a cause of neurodegeneration in HD, suggesting that inhibition of neuronal polyQ aggregation may be therapeutic in HD patients. We have used a yeast-based high-throughput screening assay to identify small-molecule inhibitors of polyQ aggregation. We validated the effects of four hit compounds in mammalian cell-based models of HD, optimized compound structures for potency, and then tested them in vitro in cultured brain slices from HD transgenic mice. These efforts identified a potent compound (IC50=10 nM) with long-term inhibitory effects on polyQ aggregation in HD neurons. Testing of this compound in a Drosophila HD model showed that it suppresses neurodegeneration in vivo, strongly suggesting an essential role for polyQ aggregation in HD pathology. The aggregation inhibitors identified in this screen represent four primary chemical scaffolds and are strong lead compounds for the development of therapeutics for human polyQ diseases.     

Proteomic analysis of mantle-cell lymphoma by protein microarray

Mantle-cell lymphoma (MCL) is a unique subtype of B-cell non-Hodgkin lymphoma (NHL) that behaves aggressively and remains incurable. In order to understand the pathogenesis of MCL and design new therapies, it is important to accurately analyze molecular changes in pathways dysregulated in MCL. We used antibody microarrays to compare patterns of protein expression between CD19(+) purified B lymphocytes from normal tonsil and 7 cases of histologically confirmed MCL. Protein overexpression was defined as a higher than 1.3-fold or 2-fold increase in at least 67% of tumor samples compared with normal B-cell control. Of the polypeptides, 77 were overexpressed using the higher than 1.3-fold cutoff, and 13 were overexpressed using the 2-fold cutoff. These included cell cycle regulators (regulator of chromosome condensation 1 [RCC1], murine double minute 2 [MDM2]), a kinase (citron Rho-interacting kinase [CRIK]), chaperone proteins (heat shock 90-kDa protein [Hsp90], Hsp10), and phosphatase regulators (A-kinase anchor protein 1 [AKAP149], protein phosphatase 5 [PP5], and inhibitor 2). The elevated expression of some of these polypeptides was confirmed by immunoblotting and immunohistochemistry, whereas elevated expression of others could not be confirmed, illustrating the importance of confirmatory studies. This study describes a novel technique that identifies proteins dysregulated in MCL.     

Engineering N-linked protein glycosylation with diverse O antigen lipopolysaccharide structures in Escherichia coli

Campylobacter jejuni has a general N-linked protein glycosylation system that can be functionally transferred to Escherichia coli. In this study, we engineered E. coli cells in a way that two different pathways, protein N-glycosylation and lipopolysaccharide (LPS) biosynthesis, converge at the step in which PglB, the key enzyme of the C. jejuni N-glycosylation system, transfers O polysaccharide from a lipid carrier (undecaprenyl pyrophosphate) to an acceptor protein. PglB was the only protein of the bacterial N-glycosylation machinery both necessary and sufficient for the transfer. The relaxed specificity of the PglB oligosaccharyltransferase toward the glycan structure was exploited to create novel N-glycan structures containing two distinct E. coli or Pseudomonas aeruginosa O antigens. PglB-mediated transfer of polysaccharides might be valuable for in vivo production of O polysaccharides-protein conjugates for use as antibacterial vaccines.     

Circadian and seasonal variation of malignant arrhythmias in a pediatric and congenital heart disease population

INTRODUCTION: Recent studies in adult populations have revealed seasonal variation in the frequency of acute cardiovascular events, including life-threatening arrhythmias, demonstrating increased events during winter and early spring. Trends in the time of day that arrhythmias occur also were noted. We sought to establish whether pediatric and young adult congenital heart disease implantable cardioverter defibrillator (ICD) recipients have circadian or seasonal variability in shock frequency, similar to adult populations. METHODS AND RESULTS: Data from ICD patients at six pediatric centers in North America were analyzed to assess the timing of life-threatening arrhythmias. The populations consisted of children and adults with congenital heart disease and ICDs placed for malignant arrhythmias. Data were considered in 46 patients who received appropriate therapy (total 139 episodes) for ventricular tachycardia or ventricular fibrillation. Multiple variables were analyzed, including time of day, day of week, and month of year. In contrast to previously studied adult patients, fewer events occurred in the early morning (7.5%), with the most therapies occurring between 6 P.M. and midnight (35%). An increased frequency of therapies was observed in the fall and winter (September-January), representing 60% of all appropriate shocks. Unlike adult populations, Mondays did not have an increased frequency of malignant arrhythmias. CONCLUSION: Pediatric and adult congenital heart disease populations have moderate seasonal and 24-hour variation in ICD event rate, with some distinctly different peaks than those seen in typical adult ICD populations. These findings suggest circadian variation in arrhythmia vulnerability that may differ from conventional occupational, physical, or emotional stressors. (J Cardiovasc Electrophysiol, Vol. 13, pp.     

Acute Limited Intimal Tears of the Thoracic Aorta

Background

Limited intimal tears (LITs) of the aorta (Class 3 dissection variant) are the least common form of aortic pathology in patients presenting with acute aortic syndrome (AAS). LITs are difficult to detect on imaging and may be underappreciated.