Improvement in the quality of abstracts in major clinical journals since CONSORT extension for abstracts: a systematic review

BACKGROUND

We sought to determine if the publication of the Consolidated Standards of Reporting Trials (CONSORT)(1) extension for abstracts in 2008 had led to an improvement in reporting abstracts of randomized controlled trials (RCTs).(2) METHODS: We searched PubMed for RCTs published in 2007 and 2012 in top-tier general medicine journals. A random selection of 100 trial abstracts was obtained for each year. Data were extracted in duplicate on the adherence to the CONSORT extension for abstracts. The primary outcome was the mean number of items reported and the secondary outcome was the odds of reporting each item. We also estimated incidence rate ratios (IRRs).(3) RESULTS: Significantly more checklist items were reported in 2012 than in 2007: adjusted mean difference was 2.91 (95% confidence interval [CI](4) 2.35, 3.41; p<0.001). In 2012 there were significant improvements in reporting the study as randomized in the title, describing the trial design, the participants, and objectives and blinding. In the Results section, trial status and numbers analyzed were also reported better. The IRRs were significantly higher for 2012 (IRR 1.32; 95% CI 1.25, 1.39; p<0.001) and in multisite studies compared to single site studies (IRR 1.08; 95% CI 1.03, 1.15; p=0.006).

CONCLUSIONS

There was a significant improvement in the reporting of abstracts of RCTs in 2012 compared to 2007. However, there is still room for improvement as some items remain under-reported.

The impact of a cardiovascular health awareness program (CHAP) on reducing blood pressure: a prospective cohort study

Background

Hypertension is an important and modifiable cardiovascular risk factor that remains under-detected and under-treated, especially in the older individuals. Community-led interventions that integrate primary health care and local resources are promising approaches to improve awareness and management of hypertension and other cardiovascular risk factors. We aimed to evaluate the effect of a community-based Cardiovascular Health Awareness Program (CHAP) on participants’ blood pressure.

Methods

This study followed a cohort of community residents that participated in CHAP across 22 mid-sized Ontario communities over an 18-month period. The participants’ baseline risk factors, including blood pressure, and subsequent measures of blood pressure were recorded. We employed a bivariate linear mixed-effect model to estimate the change of systolic and diastolic blood pressure over time among the participants who attended more than two CHAP sessions.

Results

Of 13,596 participants, 2498 attended more than two CHAP sessions. For those repeated participants (attending more than two sessions) initially identified with high blood pressure, the average reduction of systolic blood pressure was from 142 to 123 mmHg over an 18-month period, a monthly rate ratio of 0.992 (95% CI: 0.991,0.994; p < 0.01). Similarly, the average reduction of diastolic blood pressure was from 78 to 69 mmHg, a monthly rate ratio of 0.993 (95% CI: 0.991,0.994; p < 0.01). The average blood pressure of the participants with normal baseline blood pressure remained controlled and unchanged. We also found that older adult participants who lived alone, were diagnosed with hypertension, reported healthier eating habits, and presented with a higher baseline systolic blood pressure had significantly greater odds of attending more than one session.

Conclusions

CHAP was associated with a reduction in systolic and diastolic blood pressure for those participants who attended more than one session. The magnitude of blood pressure reductions was significant clinically and statistically.

HBx mutants differentially affect the activation of hypoxia-inducible factor-1α in hepatocellular carcinoma

BACKGROUND

Mutations in HBx gene are frequently found in HBV-associated hepatocellular carcinoma (HCC). Activation of hypoxia-inducible factor-1α (HIF-1α) contributes to HCC development and progression. Wild-type HBx has been demonstrated to activate HIF-1α, but the effect of HBx mutations on HIF-1α has not been elucidated.

METHODS

HBx mutations were identified by gene sequencing in 101 HCC tissues. Representative HBx mutants were cloned and transfected into HCC cells. Expression and activation of HIF-1α were analysed by western blot and luciferase assays, respectively. The relationship between HBx mutants and HIF-1α expression in HCC tissues was also evaluated.

RESULTS

The dual mutations K130M/V131I enhanced the functionality of HBx as they upregulated the expression and transcriptional activity of HIF-1α. The C-terminal truncations and deletion mutations, however, weakened the ability of HBx to upregulate HIF-1α. Meanwhile, the C-terminus was further found to be essential for the stability and transactivation of HBx. In the HCC tissues, there was a positive association between the HBx mutants and HIF-1α expression.

CONCLUSION

Different mutations of HBx exert differentiated effects on the functionality of HIF-1α, however, the overall activity of HBx mutants appears to increase the expression and transcriptional activity of HIF-1α.

Mobile phone text messages for improving adherence to antiretroviral therapy (ART): an individual patient data meta-analysis of randomised trials

OBJECTIVES

Our objectives were to analyse the effects of text messaging versus usual care in improving adherence to antiretroviral therapy (ART) in people living with HIV using individual patient data meta-analysis. Adjusted, sensitivity and subgroup analyses were conducted.

SETTING

3 randomised controlled trials conducted between 2010 and 2012 in rural and urban centres in Cameroon and Kenya (two studies) were used.

PARTICIPANTS

A total of 1166 participants were included in this analysis (Cameroon=200; Kenya=428 and 538).

PRIMARY AND SECONDARY OUTCOMES

The primary outcome was adherence to ART >95%. The secondary outcomes were mortality, losses to follow-up, transfers and withdrawals.

RESULTS

Text messaging improved adherence to ART (OR 1.38; 95% CIs 1.08 to 1.78; p=0.012), even after adjustment for baseline covariates (OR 1.46; 95% CI 1.13 to 1.88; p=0.004). Primary education (compared with no formal education) was associated with a greater intervention effect on adherence (OR 1.65; 95% CI 1.10 to 2.48; p=0.016) and also showed a significant subgroup effect (p=0.039). In sensitivity analysis, our findings were robust to a modified threshold of adherence, multiple imputation for missing data and aggregate level data pooling, but not to fixed-effects meta-analyses using generalised estimation equations. There was a significant subgroup effect for long weekly (p=0.037), short weekly text messages (p=0.014) and interactive messaging (p=0.010). Text messaging did not significantly affect any of the secondary outcomes.

CONCLUSIONS

Text messaging has a significant effect on adherence to ART, and this effect is influenced by level of education, gender, timing (weekly vs daily) and interactivity. We recommend the use of interactive weekly text messaging to improve adherence to ART, which is most effective in those with at least a primary level of education.

Effect of maternal gestational diabetes on the cardiovascular risk factor profile of infants at 1 year of age

BACKGROUND AND AIM

Offspring of women with gestational diabetes (GDM) exhibit an adverse cardiovascular risk factor profile by as early as age 5 years. Recently, maternal glycemia has been associated with epigenetic modification of genes on the fetal side of the placenta, including those encoding emerging risk factors (adiponectin, leptin), suggesting that vascular differences may emerge even earlier in life. Thus, we sought to evaluate cardiovascular risk factors and determinants thereof in 1-year-old infants of women with and without GDM.

METHODS AND RESULTS

Traditional (glucose, lipids) and emerging (C-reactive protein (CRP), adiponectin, leptin) risk factors were assessed in pregnancy in 104 women with (n = 36) and without GDM (n = 68), and at age 1-year in their offspring. In pregnancy, women with GDM had higher triglycerides (2.49 vs 2.10 mmol/L, p = 0.04) and CRP (5.3 vs 3.6 mg/L, p = 0.03), and lower adiponectin (7.3 vs 8.5 μg/mL, p = 0.04) than did their peers. At age 1-year, however, there were no differences in cardiovascular risk factors (including adiponectin) between the infants of women with and without GDM. Of note, maternal and infant adiponectin levels were associated in the non-GDM group (r = 0.39, p = 0.001) but not in the GDM group (r = 0.07, p = 0.67). Furthermore, on multiple linear regression analyses, maternal adiponectin emerged as an independent predictor of infant adiponectin in the non-GDM group only (beta = 776.1, p = 0.0065).

CONCLUSION

Infants of women with and without GDM have a similar cardiovascular risk factor profile at age 1-year. However, there are differences in their early-life determinants of adiponectin that may be relevant to the subsequent vascular risk of GDM offspring.

A look at the potential association between PICOT framing of a research question and the quality of reporting of analgesia RCTs

Background

Methodologists have proposed the formation of a good research question to initiate the process of developing a research protocol that will guide the design, conduct and analysis of randomized controlled trials (RCTs), and help improve the quality of reporting such studies. Five constituents of a good research question based on the PICOT framing include: Population, Intervention, Comparator, Outcome, and Time-frame of outcome assessment. The aim of this study was to analyze if the presence a structured research question, in PICOT format, in RCTs used within a 2010 meta-analysis investigating the effectiveness of femoral nerve blocks after total knee arthroplasty, is independently associated with improved quality of reporting.

Methods

Twenty-three RCT reports were assessed for the quality of reporting and then examined for the presence of the five constituents of a structured research question based on PICOT framing. We created a PICOT score (predictor variable), with a possible score between 0 and 5; one point for every constituent that was included. Our outcome variable was a 14 point overall reporting quality score (OQRS) and a 3 point key methodological items score (KMIS) based on the proper reporting of allocation concealment, blinding and numbers analysed using the intention-to-treat principle. Both scores, OQRS and KMIS, are based on the Consolidated Standards for Reporting Trials (CONSORT) statement. A multivariable regression analysis was conducted to determine if PICOT score was independently associated with OQRS and KMIS.

Results

A completely structured PICOT score question was found in 2 of the 23 RCTs evaluated. Although not statistically significant, higher PICOT was associated with higher OQRS [IRR: 1.267; 95% confidence interval (CI): 0.984, 1.630; p = 0.066] but not KMIS (1.061 (0.515, 2.188); 0.872). These results are comparable to those from a similar study in terms of the direction and range of IRRs estimates. The results need to be interpreted cautiously due to the small sample size.

Conclusions

This study showed that PICOT framing of a research question in anesthesia-related RCTs is not often followed. Even though a statistically significant association with higher OQRS was not found, PICOT framing of a research question is still an important attribute within all RCTs.

A sensitivity analysis of the Children's Treatment Network trial: a randomized controlled trial of integrated services versus usual care for children with special health care needs

Background

The value of integrated care through comprehensive, coordinated, and family-centered services has been increasingly recognized for improving health outcomes of children with special health care needs (CSHCN). In a randomized controlled trial (RCT), the integrated care provided through the Children’s Treatment Network (CTN) was compared with usual care in improving the psychosocial health of target CSHCN. In this paper, we aimed to estimate the effect of CTN care by conducting multiple analyses to handle noncompliance in the trial.

Methods

The trial recruited target children in Simcoe County and York Region, ON, Canada. Children were randomized to receive CTN or usual care and were followed for 2 years. The CTN group received integrated services through multiple providers to address their specific needs while the usual care group continued to receive care directed by their parents. The outcome was change in psychosocial quality of life at 2 years. We conducted intention-to-treat, as-treated, per-protocol, and instrumental variable analyses to analyze the outcome.

Results

The trial randomized 445 children, with 229 in the intervention group and 216 in the control group. During follow-up, 52% of children in the intervention group did not receive complete CTN care for various reasons. At 2 years, we did not find a significant improvement in psychosocial quality of life among the children receiving CTN care compared with usual care (intention-to-treat mean difference 1.50, 95% confidence interval −1.49 to 4.50; P = 0.32). Other methods of analysis yielded similar results.

Conclusion

Although the effect of CTN care was not significant, there was evidence showing benefits of integrated care for CSHCN. More RCTs are needed to demonstrate the magnitude of such an effect. The CTN study highlights the key challenges in RCTs when assessing interventions involving integrated care, and informs further RCTs including similar evaluations.

The effect of regular physical activity on bone mineral density in post-menopausal women aged 75 and over: a retrospective analysis from the Canadian multicentre osteoporosis study

Background

Physical activity is known to benefit many physiological processes, including bone turnover. There are; however, currently no clinical guidelines regarding the most appropriate type, intensity and duration of activity to prevent bone loss.

Methods

To help address this gap in the literature, we performed a retrospective analysis of data from the Canadian Multicentre Osteoporosis Study (CaMos), a prospective cohort of 9423 adult patients, to determine the relationship between the amount of regular daily physical activity performed and bone mineral density. A total of 1169 female participants aged 75 and over provided information regarding their daily activity levels, including the amount of time spent each week performing physical activity at varying levels of intensity. Multiple and linear regression analyses were used to determine the effect of increasing amounts of this regular physical activity on bone mineral density.

Results

The results indicate that a step increase in the amount of physical activity performed each day resulted in a positive effect on bone mineral density at the hip, Ward’s triangle, trochanter and femoral neck (B = 0.006 to 0.008, p < 0.05). Possible confounding factors such as the use of anti-resorptive therapy, body mass index and age were included in the analysis and suggested that age had a negative effect on bone density while body mass index had a positive effect. Anti-resorptive therapy provided a protective effect against loss of bone density.

Conclusions

The data indicate that a step increase in the amount of daily activity, using simple, daily performed tasks, can help prevent decreases in post-menopausal bone mineral density.

A tutorial on sensitivity analyses in clinical trials: the what, why, when and how

BACKGROUND

Sensitivity analyses play a crucial role in assessing the robustness of the findings or conclusions based on primary analyses of data in clinical trials. They are a critical way to assess the impact, effect or influence of key assumptions or variations--such as different methods of analysis, definitions of outcomes, protocol deviations, missing data, and outliers--on the overall conclusions of a study.The current paper is the second in a series of tutorial-type manuscripts intended to discuss and clarify aspects related to key methodological issues in the design and analysis of clinical trials.

DISCUSSION

In this paper we will provide a detailed exploration of the key aspects of sensitivity analyses including: 1) what sensitivity analyses are, why they are needed, and how often they are used in practice; 2) the different types of sensitivity analyses that one can do, with examples from the literature; 3) some frequently asked questions about sensitivity analyses; and 4) some suggestions on how to report the results of sensitivity analyses in clinical trials.

SUMMARY

When reporting on a clinical trial, we recommend including planned or posthoc sensitivity analyses, the corresponding rationale and results along with the discussion of the consequences of these analyses on the overall findings of the study.

Intra-abdominal hypertension in the critically ill: interrater reliability of bladder pressure measurement

PURPOSE

Intra-abdominal hypertension is frequently underdiagnosed and defined by intra-abdominal pressure (IAP) 12 mm Hg or higher. Increasing IAP may compromise organ viability and culminate in abdominal compartment syndrome. Bladder pressure measurement is a surrogate for IAP, but measurement properties are unknown in the intensive care unit. Our primary objective was to assess the agreement of bladder pressure measurements in critically ill patients.

METHODS

We conducted an observational study examining the correlation of measurement variability of bladder pressure. Four raters (2 nurses and 2 physicians) measured IAP. Patient's age, Acute Physiology and Chronic Health Evaluation II, body mass index, mechanical ventilation parameters, and demographics were collected.

RESULTS

Fifty-one patients had bladder pressures measured in quadruplicate, producing 204 measurements. Among 51 patients, the mean age was 61.9 years, Acute Physiology and Chronic Health Evaluation II was 23.8, and body mass index was 27.8 kg/m2. The average bladder pressure was 12.4 (SD, ±6.2) mm Hg. The interrater agreement by intraclass correlation coefficient was 0.745 (95% confidence interval [CI], 0.637-0.825), 0.804 (95% CI, 0.684-0.882), and 0.626 (95% CI, 0.428-0.767) among all raters, physicians, and nurses, respectively.

CONCLUSIONS

Agreement on bladder pressure was high among 4 clinicians and were not significantly different between physicians and nurses. Given that medical/surgical treatments are considered on bladder pressure values, understanding their reliability is essential to monitor critically ill patients.

Area-under-the-HbA1c-curve above the normal range and the prediction of microvascular outcomes: an analysis of data from the Diabetes Control and Complications Trial

AIMS

In the Diabetes Control and Complications Trial, mean updated HbA(1c) accounted for most of the differential risk of microvascular complications between intensive and conventional insulin therapy. We hypothesized, however, that a more precise measure of chronic hyperglycaemic exposure may be the incremental area-under-the-HbA(1c)-curve above the Diabetes Control and Complications Trial-standardized normal range for HbA(1c) (iAUC(HbA1c>norm)).

METHODS

Using the Principal Diabetes Control and Complications Trial data set, we compared the following three measures of chronic glycaemic exposure for their capacity to predict retinopathy, nephropathy and neuropathy during the Diabetes Control and Complications Trial: mean updated HbA(1c), iAUC(HbA1c>norm), and total area-under-the-HbA(1c)-curve (tAUC(HbA1c)). For each outcome, models using each of these three glycaemic measures were compared in the following three ways: hazard or odds ratio, χ(2) statistic, and Akaike information criterion.

RESULTS

The three glycaemic measures did not differ in their prediction of neuropathy. iAUC(HbA1c>norm) was modestly superior to mean updated HbA(1c) for predicting nephropathy (χ(2) P = 0.017, Akaike P = 0.032). In contrast, for predicting retinopathy, both iAUC(HbA1c>norm) (χ(2) P = 0.0005, Akaike P = 0.0005) and tAUC(HbA1c) (χ(2) P = 0.004, Akaike P = 0.004) were significantly better than mean updated HbA(1c). Varying its HbA(1c) threshold incrementally between 37 and 53 mmol/mol (5.5-7.0%), inclusive, did not improve the prediction of retinopathy by iAUC(HbA1c>threshold) beyond that of tAUC(HbA1c,) consistent with the concept of a continuous relationship between glycaemia and retinopathy, with no glycaemic threshold.

CONCLUSIONS

Both iAUC(HbA1c>norm) and tAUC(HbA1c) were superior to mean updated HbA(1c) for predicting retinopathy. Optimal assessment of chronic glycaemic exposure as a determinant of retinopathic risk may require consideration of both the degree of hyperglycaemia and its duration.

Maternal pregravid weight is the primary determinant of serum leptin and its metabolic associations in pregnancy, irrespective of gestational glucose tolerance status

CONTEXT

Several previous studies have investigated circulating levels of the adipokine leptin in relation to gestational diabetes mellitus (GDM). However, these studies have yielded markedly conflicting results, including increased, decreased, and unchanged leptin levels in women with GDM as compared with their peers.

OBJECTIVE

We sought to evaluate the metabolic determinants of serum leptin in a well-characterized cohort reflecting the full spectrum of glucose intolerance in pregnancy.

DESIGN, SETTING, AND PARTICIPANTS

Metabolic characterization, including oral glucose tolerance test (OGTT) and measurement of serum leptin, insulin, lipids, adiponectin, and C-reactive protein, was performed in 817 pregnant women. The OGTT identified 198 women with GDM, 142 with gestational impaired glucose tolerance, and 477 with normal glucose tolerance.

RESULTS

Median leptin (ng/ml) did not differ between the normal glucose tolerance (33.7), gestational impaired glucose tolerance (36.3), and GDM (36.4) groups (P = 0.085). On univariate correlation analysis, leptin was most strongly associated with prepregnancy body mass index (BMI) (r = 0.54, P < 0.0001), fasting insulin (r = 0.60, P < 0.0001), and C-reactive protein (r = 0.38, P < 0.0001) but only weakly associated with area under the glucose curve (AUC(glucose)) on the OGTT (r = 0.10, P = 0.0066). On multiple linear regression analysis, the strongest independent determinant of leptin was prepregnancy BMI (t = 11.55, P < 0.0001), whereas AUC(glucose) was not a significant predictor (t = -0.95, P = 0.34). Furthermore, although its respective associations with fasting insulin, triglycerides, and adiponectin varied across tertiles of prepregnancy BMI, leptin was not significantly associated with AUC(glucose) in any BMI tertile.

CONCLUSIONS

Pregravid BMI, rather than gestational glucose tolerance, is the primary determinant of serum leptin concentration in pregnancy.

Motivational interviewing for improving outcomes in youth living with HIV

BACKGROUND

Almost half of all the new HIV infections occur in youth. Motivational interviewing (MI) is a counselling technique that is effective in bringing about positive behavior changes in the general population. It is unclear whether it can be used to improve outcomes in youth living with HIV.

OBJECTIVES

To determine whether MI is effective in improving outcomes in youth living with HIV.

SEARCH METHODS

We used a comprehensive and exhaustive strategy in an attempt to identify all relevant studies, regardless of language or publication status, in electronic databases (PubMed, the Cochrane Central Register of Controlled Trials, EMBASE, LILACS, CINAHL, PsycINFO), conference proceedings and specialised databases from January 1980 to March 2012.

SELECTION CRITERIA

Randomised controlled trials (RCTs) in which youth (aged 10 to 24) living with HIV received MI, singly or in combination with another intervention compared to any other intervention, and reporting on the outcomes of interest (adherence to medication, mortality, quality of life, viral load, CD4-positive-T-lymphocyte count, progression to AIDS, retention in care, substance abuse and condom use). All settings were considered.

DATA COLLECTION AND ANALYSIS

We identified 863 references.Two authors independently examined the titles and abstracts of all identified trials, of which 28 full-text articles were closely screened for eligibility based on criteria established a-priori. The included studies were appraised for quality in duplicate. Data were extracted using a pre-tested and standardised form. No meta-analyses were performed.

MAIN RESULTS

Two trials located in the United States, reported in four papers met our inclusion criteria. They enrolled a total of 237 participants and compared motivational interviewing singly to standard of care. None of these trials reported on adherence to HIV medication, mortality or quality of life. Both trials reported reductions in viral load (in the short term) and unprotected sexual acts. A reduction in alcohol use was identified only in one of two studies that reported on this outcome. One trial reported on retention. Retention rates were not affected by the intervention.

AUTHORS' CONCLUSIONS

There is moderate quality evidence, coming from two trials which suggests that MI is effective in reducing short term viral load and unprotected sexual acts. There is moderate quality evidence from one trial that MI is effective in reducing alcohol use. There is a need for more trials which report on outcomes such as adherence to medication, mortality and quality of life in youth.

The quality of reporting of RCTs used within a postoperative pain management meta-analysis, using the CONSORT statement

Background

Randomized controlled trials (RCTs) are routinely used in systematic reviews and meta-analyses that help inform healthcare and policy decision making. The proper reporting of RCTs is important because it acts as a proxy for health care providers and researchers to appraise the quality of the methodology, conduct and analysis of an RCT. The aims of this study are to analyse the overall quality of reporting in 23 RCTs that were used in a meta-analysis by assessing 3 key methodological items, and to determine factors associated with high quality of reporting. It is hypothesized that studies with larger sample sizes, that have funding reported, that are published in journals with a higher impact factor and that are in journals that have adopted or endorsed the CONSORT statement will be associated with better overall quality of reporting and reporting of key methodological items.

Methods

We systematically reviewed RCTs used within an anesthesiology related post-operative pain management meta-analysis. We included all of the 23 RCTs used, all of which were parallel design that addressed the use of femoral nerve block in improving outcomes after total knee arthroplasty. Data abstraction was done independently by two reviewers. The two main outcomes were: 1) 15 point overall quality of reporting score (OQRS) based on the Consolidated Standards for Reporting Trials (CONSORT) and 2) 3 point key methodological item score (KMIS) based on allocation concealment, blinding and intention-to-treat analysis.

Results

Twenty-three RCTs were included. The median OQRS was 9.0 (Interquartile Range = 3). A multivariable regression analysis did not show any significant association between OQRS or KMIS and our four predictor variables hypothesized to improve reporting. The direction and magnitude of our results when compared to similar studies suggest that the sample size and impact factor are associated with improved key methodological item reporting.

Conclusions

The quality of reporting of RCTs used within an anesthesia related meta-analysis is poor to moderate. The information gained from this study should be used by journals to register the urgency for RCTs to be clear and transparent in reporting to help make literature accessible and comparable.

Measuring the degree of integration for an integrated service network

BACKGROUND

Integration involves the coordination of services provided by autonomous agencies and improves the organization and delivery of multiple services for target patients. Current measures generally do not distinguish between agencies' perception and expectation. We propose a method for quantifying the agencies' service integration. Using the data from the Children's Treatment Network (CTN), we aimed to measure the degree of integration for the CTN agencies in York and Simcoe.

THEORY AND METHODS

We quantified the integration by the agreement between perceived and expected levels of involvement and calculated four scores from different perspectives for each agency. We used the average score to measure the global network integration and examined the sensitivity of the global score.

RESULTS

Most agencies' integration scores were <65%. As measured by the agreement between every other agency's perception and expectation, the overall integration of CTN in Simcoe and York was 44% (95% CI: 39%-49%) and 52% (95% CI: 48%-56%), respectively. The sensitivity analysis showed that the global scores were robust.

CONCLUSION

Our method extends existing measures of integration and possesses a good extent of validity. We can also apply the method in monitoring improvement and linking integration with other outcomes.

Discordant effects on central obesity, hepatic insulin resistance, and alanine aminotransferase of low-dose metformin and thiazolidinedione combination therapy in patients with impaired glucose tolerance

Alanine aminotransferase (ALT) predicts incident type 2 diabetes (T2DM), possibly reflecting early fatty liver and hepatic insulin resistance. Thiazolidinediones and metformin can improve fatty liver and hepatic insulin resistance, respectively. In the Canadian Normoglycemia Outcome Evaluation trial, rosiglitazone/metformin (Rosi/Met, 4/1000 mg) reduced incident T2DM by 66% in subjects with impaired glucose tolerance. For insight on the hepatic effects of this therapy in relation to T2DM, we evaluated the temporal changes in waist, hepatic insulin sensitivity (1/Homeostasis Model Assessment of Insulin Resistance) and ALT in the Rosi/Met (n = 103) and placebo (n = 104) arms over median of 3.9 years. Waist did not differ between the arms. Hepatic insulin sensitivity improved in the Rosi/Met arm in year 1, but deteriorated thereafter as in the placebo arm. In contrast, Rosi/Met lowered ALT in year 1 and maintained this effect throughout the trial. Thus, low-dose Rosi/Met had no effect on central obesity, a transient effect on hepatic insulin sensitivity, and a sustained effect on ALT.

Endovascular stent-graft treatment for Stanford type A aortic dissection

OBJECTIVE

The aim of the study is to summarise our experience of endovascular stent grafting for Stanford type A aortic dissection.

DESIGN

Retrospective analysis at single centre.

METHODS

From January 2001 to January 2009, we treated 45 cases of Stanford type A aortic dissection with endovascular stent grafting. The entry tear was located at the ascending aorta in 10 cases (DeBakey type I), the aortic arch in 14 cases and the distal aortic arch or proximal descending aorta in 21 cases in which the ascending aorta was also involved by the dissection.

RESULTS

The surgical success rate was 97.8% (44/45) and 30-day mortality rate was 6.7% (3/45). Type I endoleaks occurred in 10 cases: one patient died intra-operatively, four were successfully treated with ballooning, four were sealed with aortic cuffs and one case caused by left subclavian artery (LSA) reflux was sealed with an occluder. Average follow-up time was 35.5 ± 5.4 months. Up to the most recent review or death, 32 patients had complete thrombosis and 10 had partial thrombosis inside the false lumen. Two deaths occurred after 30-days postoperatively.

CONCLUSION

Endovascular stent-graft treatment is a minimally invasive and effective method to treat Stanford type A aortic dissection.

Associations and costs of parental symptoms of psychiatric distress in a multi-diagnosis group of children with special needs

BACKGROUND

Families supporting children with complex needs are significantly more distressed and economically disadvantaged than families of children without disability and delay. What is not known is the associations and costs of parental psychiatric distress within a multi-diagnosis group of special needs children.

METHODS

In this cross-sectional survey, families were identified from the Children's Treatment Network. Families were eligible if the child was aged 0-19 years, resided in Simcoe/York, and if there were multiple family needs (n = 429).

RESULTS

Some 42% of surveyed parents exhibited symptoms (mild to severe) of psychiatric distress. The presence of these symptoms was associated with reports of poorer social support, family dysfunction, greater adverse impact of the child's situation on the family, poorer child behaviour, unfavourable parenting styles and poorer child psychosocial functioning. The severity of the child's physical dysfunction was not related to parents/guardians most knowledgeable symptoms of psychiatric distress. Total parent costs were higher and children's uses of primary care services were higher in parents with symptoms of psychiatric distress.

CONCLUSION

Parent symptoms of psychiatric distress are a significant societal concern in families with complex needs children. Children's rehabilitation efforts need to incorporate parental mental health assessment and treatment into existing programmes. This could lead to decreases in direct and indirect healthcare utilisation costs.

Rational Construction of Polymeric Nonlinear Optical Materials. Properties of Chromophore-Functionalized Polystyrenes

Processable polymeric nonlinear optical materials can be synthesized by functionalizing a glassy macromolecule with chromophores having large quadratic hyperpolarizabilities, followed by poling in an electric field. In the present case, the functionalization of polystyrene with 4- (4-nitrophenylaza)(N-ethyl)(2-hydroxyethyl))aniline, 4-(4-N,N-dimethylaminostyryl) pyridine, and N-(4-nitrophenyl)-L-prolinol is described. Particularly noteworthy is the high level of chromophore units that can be incorporated into transparent films of these materials, the high second harmonic coefficients that can be achieved (as high as d33 – 11 × 10-9 esu at 1064 nm), and the long-term temporal stability of the second harmonic generation capacity.

Applications of PZT and Related Thin Films in Piezoelectric Microsensors

Ferroelectric thin films have been deposited on polycrystalline silicon micromechanical structures to form both physical microsensors and microactuator devices. These devices which include acoustic pressure sensors, infrared detectors, micropositioners, and stepper motors are based on either the piezoelectric or pyroelectric properties of sol-gel Pb(ZrxTi1-x)O3 or PbTiO3 deposited on surface-machined microelectromechanical structures. Several materials, micromachining, process integration, and performance issues are introduced in the description of these devices.

Data withdrawal in randomized controlled trials: Defining the problem and proposing solutions: a commentary

It is not uncommon for a participant to withdraw from a randomized controlled trial (RCT). The withdrawal of a participant results in missing data and the potential for withdrawal bias. Data withdrawal, or a request from a participant to withdraw all of their previously collected data from a study, is particularly problematic because it leaves little opportunity to characterize or statistically address those that have withdrawn to minimize withdrawal bias. The aim of this commentary is to (1) provide a synthesis of available information on the ethical and methodological issues related to data withdrawal in RCTs and (2) provide some suggestions on how to minimize the impact of data withdrawal during the execution or analysis phases of an RCT. We searched PubMed, EMBASE and JSTOR for published articles on data withdrawal. In addition, we used internet sources as an additional tool to identify content on data withdrawal from research ethics guidelines, legislation, research ethics boards, funding agencies, professional organizations and researchers. We did not find any definitive guidelines for dealing with data withdrawal. We propose recommendations for minimizing the occurrence of data withdrawal, including explicit and clear descriptions in consent forms of how data will be handled after participant withdrawal. We also suggest using imputation techniques to deal with the missing data during analysis. The current commentary can be used to minimize the impact of data withdrawal in RCTs.

High glucose induces dysfunction and apoptosis in endothelial cells: is the effect of high glucose persistence more important than concentration?

Oxidative stress and inflammation are involved in the pathogenesis of diabetic endothelial dysfunction. Herein we reported the biological changes induced by hyperglycemia in human umbilical vein endothelial cells (HUVECs) and the potential underlying mechanisms sought to determine whether high glucose concentration or the persistence plays a key role in the development of vascular lesions. The HUVECs were exposed to various glucose concentrations (5, 15, 30, and 60 mmol/L of D-glucose supplemented), and several oxidative stress factors, such as NO, NOS, and ROS, and inflammatory signaling markers, such as TNF-α, TNFR, RIP, TRADD, TRAF-2 and NF-κB, were analyzed at various times (24, 48, 72, and 96 h). High glucose (HG) induced a transient increase of NO within 24 h and decreased afterwards, in accord with the expression of eNOS. HG also increased ROS and TNF-α production and activated the TNF-α-mediated signal transduction, decreasing cell viability and inducing apoptosis. However, 3 HG groups had similar effects on HUVECs with the increased duration of exposure, which resulted in the amplified oxidative and inflammatory damage. Taken together, these findings suggest that the HG persistence exacerbates oxidative stress and activates the inflammatory-mediated signaling pathways, inducing endothelial dysfunction and apoptosis, regardless of the concentration of HG. Our results provide the first evidence that HG persistence is more important than concentration in the progress of diabetic endothelial dysfunction.

Quasi-steady-state and steady-state models for heat and moisture transport in textile assemblies

Heat and moisture transport plays an important role in many engineering areas. In many sweat transport systems, such as clothing assembly, the moisture concentration (or sweat) is relative small and the air concentration reaches a steady state quickly. In this paper, a quasi-steady-state multi-component and multi-phase model for heat and moisture transport in porous textile materials with phase change is proposed. An analytic form of the air concentration is obtained in terms of the mixture gas (vapour and air) concentration and temperature. The new model is described in the form of a single-component flow with an extra air resistance (permeability), involving only the vapour concentration (or pressure), temperature and water content. The existence of the classical positive solutions of the corresponding steady-state model is proved. Two types of clothing assemblies are investigated numerically. The comparisons among the experimental measurements and numerical results of the fully dynamic model, the proposed quasi-steady-state model and steady-state model are also presented. Numerical results show that the proposed quasi-steady-state model is realistic and less complicated.

Association between framing of the research question using the PICOT format and reporting quality of randomized controlled trials

Background

Experts recommend formulating a structured research question to guide the research design. However, the basis for this recommendation has not been formally evaluated. The aim of this study was to examine if a structured research question using the PICOT (Population, Intervention, Comparator, Outcome, Time-frame) format is associated with a better reporting quality of randomized controlled trials (RCTs).

Methods

We evaluated 89 RCTs reports published in three endocrinology journals in 2005 and 2006, the quality of reporting of which was assessed in a previous study. We examined whether the reports stated each of the five elements of a structured research question: population, intervention, comparator, outcome and time-frame. A PICOT score was created with a possible score between 0 and 5. Outcomes were: 1) a 14-point overall reporting quality score (OQS) based on the Consolidated Standards for Reporting Trials; and 2) a 3-point key score (KS), based on allocation concealment, blinding and use of intention-to-treat analysis. We conducted multivariable regression analyses using generalized estimating equations to determine if a higher PICOT score or the use of a structured research question were independently associated with a better reporting quality. Journal of publication, funding source and sample size were identified as factors associated with OQS in our previous report on this dataset, and therefore included in the model.

Results

A higher PICOT score was independently associated with OQS (incidence rate ratio (IRR) = 1.021, 95% CI: 1.012 to 1.029) and KS (IRR = 1.142, 95% CI: 1.079 to 1.210). A structured research question was present in 33.7% of the reports and it was associated with a better OQS (IRR = 1.095, 95% CI 1.059-1.132) and KS (IRR = 1.530, 95% CI 1.311-1.786).

Conclusions

Better framing of the research question using the PICOT format is independently associated with better overall reporting quality - although the effect is small - and better reporting of key methodologies.

Mitogenic effect contributes to increased virulence of Streptococcus suis sequence type 7 to cause streptococcal toxic shock-like syndrome

Streptococcus suis serotype 2 sequence type 7 strains emerged in 1996 and caused a streptococcal toxic shock-like syndrome in 1998 and 2005 in China. Evidence indicated that the virulence of S. suis sequence type 7 had increased, but the mechanism was unknown. The sequence type 7 strain SC84, isolated from a patient with streptococcal toxic shock-like syndrome during the Sichuan outbreak, and the sequence type 1 strain 31533, a typical highly pathogenic strain isolated from a diseased pig, were used in comparative studies. In this study we show the mechanisms underlying cytokine production differed between the two types of strains. The S. suis sequence type 7 strain SC84 possesses a stronger capacity to stimulate T cells, naive T cells and peripheral blood mononuclear cell proliferation than does S. suis sequence type 1 strain 31533. The T cell response to both strains was dependent upon the presence of antigen-presenting cells. Histo-incompatible antigen-presenting cells were sufficient to provide the accessory signals to naive T cell stimulated by the two strains, indicating that both sequence type 7 and 1 strains possess mitogens; however, the mitogenic effect was different. Therefore, we propose that the difference in the mitogenic effect of sequence type 7 strain SC84 compared with the sequence type 1 strain 31533 of S. suis may be associated with the clinical, epidemiological and microbiological difference, where the ST 7 strains have a larger mitogenic effect.

Posing the research question: not so simple

PURPOSE

The success of any research process relies, in part, on how well investigators are able to translate a clinical problem into a research question-a task that is not so simple for novice investigators. The PICOT approach requires that the framing of the research question specify the target Population, the Intervention of interest, the Comparator intervention, key Outcomes, and the Time frame over which the outcomes are assessed. This paper describes the use of the PICOT structure in framing research questions and examines PICOT criteria as applied to the anesthesia literature. We also provide a roadmap for applying the PICOT format in identifying and framing clear research questions.

METHODS

In addition to searching MEDLINE for the literature on framing research questions, we performed a systematic review of articles published in four key anesthesia journals in 2006, including Anesthesiology, Anesthesia & Analgesia, the British Journal of Anaesthesia, and the Canadian Journal of Anesthesia.

RESULTS

Three hundred thirteen articles (n = 313) were included in this review, with the following distribution by study design: 139 (44%) randomized controlled trials, 129 (41%) cohort studies, and 45 (15%) case-controlled, cross-sectional studies or systematic reviews. Overall, 96% (95% confidence interval: 91,100) of articles did not apply the PICOT approach in reporting the research question.

CONCLUSIONS

The PICOT approach may be helpful in defining and clearly stating the research question. It remains to be determined whether or not compliance with the PICOT style, or any other format for framing research questions, is associated with a higher quality of research reporting.

An intelligent mobile vehicle navigator based on fuzzy logic and reinforcement learning

In this paper, an alternative training approach to the EEM-based training method is presented and a fuzzy reactive navigation architecture is described. The new training method is 270 times faster in learning speed; and is only 4% of the learning cost of the EEM method. It also has very reliable convergence of learning; very high number of learned rules (98.8%); and high adaptability. Using the rule base learned from the new method, the proposed fuzzy reactive navigator fuses the obstacle avoidance behaviour and goal seeking behaviour to determine its control actions, where adaptability is achieved with the aid of an environment evaluator. A comparison of this navigator using the rule bases obtained from the new training method and the EEM method, shows that the new navigator guarantees a solution and its solution is more acceptable.

Quantitation of SU11248, an oral multi-target tyrosine kinase inhibitor, and its metabolite in monkey tissues by liquid chromatograph with tandem mass spectrometry following semi-automated liquid–liquid extraction

SU11248 is a potent inhibitor of PDGFR, VEGFR, KIT, and Flt3, and is currently under Phase I clinical evaluation as an anticancer drug. A sensitive and specific analytical method for the quantitation of SU11248 and its metabolite in several monkey tissues (liver, kidney, brain and white fat) using LC-MS-MS following semi-automated liquid-liquid extraction (LLE) was developed and validated. Amounts of 50 mg of tissue were homogenized using an ultrasonic processor. After addition of the stable labelled internal standard (IS) and ammonium hydroxide (0.3%), samples were extracted with 2.5 ml of tert-butyl methyl ether. Following centrifugation, aliquots of 1.8 ml of the organic phase were transferred into a 96-well plate. The Packard Multiprobe II robotic liquid handler was used to perform all steps mentioned above. The organic phase was dried and the residue was reconstituted with 800 microl of 15 mM ammonium formate buffer solution (pH 3.25) using a Tomtec Quadra 96 workstation. Aliquots of 10 microl of the resulting solution were injected into the LC-MS-MS system. A Symmetry Shield C8 column (50 mm x 2.1 mm, 3.5 microm) was used to perform the chromatographic analysis. The mobile phase was 15 mM ammonium formate buffer solution (pH 3.25)-acetonitrile (74:26 (v/v)) with a flow-rate of 0.35 ml/min. Retention times of the metabolite and SU11248 were about 2.5 and 3.5 min, respectively. Total cycle time was 5 min. MS detection used the Applied Biosystems-MDS Sciex API 3000 with TurbolonSpray interface and multiple reaction monitoring (MRM) operated in positive ion mode. The method was validated for both compounds over the calibration range of about 2 and 2000 ng/g. The suitability and robustness of the method for in vivo samples were confirmed by analysis of monkey tissues from animals dosed with SU11248.

[Preparation and analysis of pure type II collagen from porcine articular cartilage]

This investigation was aimed at the preparation of pure type II collagen from porcine articular cartilage and the feasible method for producing type II collagen in bulk. After dispersal of the porcine articular cartilage, the proteoglycans were extracted by guanidinium hydrochloride and dissolved by pepsin in acid solvent. The contaminants including denatured and degraded protein and other collagen was removed via the repeated procedure of purification. For obtaining the purer type II collagen, the chromatography with sepharose H. P. Column was also used. The purity of the sample was compared with the type II collagen produced by Sigma Company. Both type II collagens were characterized by SDS-PAGE electrophoresis, amino acid analysis and maximal violet chromatography, and all of the results accorded with the standard photograph in the references. The purity of the sample was higher than that of the product of Sigma Company. This prepared collagen of type II is a product of high purity. The raw materials are the common porcine articular cartilage, which is rich in resource and low in cost. Therefore, it is suitable to produce type II collagen in batches.