Lukman Thalib

A quality-effects model for meta-analysis

We introduce a quality-effects approach that combines evidence from a series of trials comparing 2 interventions. This approach incorporates the heterogeneity of effects in the analysis of the overall interventional efficacy. However, unlike the random-effects model based on observed between-trial heterogeneity, we suggest adjustment based on measured methodological heterogeneity between studies. We propose a simple noniterative procedure for computing the combined effect size under this model and suggest that this could represent a more convincing alternative to the random effects model.

Effect of using a safety checklist on patient complications after surgery: a systematic review and meta-analysis.

Background:Previous before-and-after studies indicate that the use of safety checklists in surgery reduces complication rates in patients. Methods:A systematic review of studies was undertaken using MEDLINE, CINAHL, Proquest, and the Cochrane Library to identify studies that evaluated the effects of checklist use in surgery on complication rates. Study quality was assessed using the Methodological Index for Nonrandomized Studies. The pooled risk ratio (RR) was estimated using both fixed and random effects models. For each outcome, the number needed to treat (NNT) and the absolute risk reduction (ARR) were also computed. Results:Of the 207 intervention studies identified, 7 representing 37,339 patients were included in meta-analyses, and all were cohort studies. Results indicated that the use of checklists in surgery compared with standard practice led to a reduction in any complication (RR, 0.63; 95% CI, 0.58 to 0.72; P < 0.0001; ARR, 3.7%; NNT, 27) and wound infection (RR, 0.54; 95% CI, 0.40 to 0.72; P = 0.0001; ARR, 2.9%; NNT, 34) and also reduction in blood loss (RR, 0.56; 95% CI, 0.45 to 0.70; P = 0.0001; ARR, 3.8%; NNT, 33). There were no significant reductions in mortality (RR, 0.79; 95% CI, 0.57 to 1.11; P = 0.191; ARR, 0.44%; NNT, 229), pneumonia (RR, 1.03; 95% CI, 0.73 to 1.4; P = 0.857; ARR, 0.04%; NNT, 2,512), or unplanned return to operating room (RR, 0.75; 95% CI, 0.56 to 1.02; P = 0.068; ARR, 0.52%; NNT, 192). Conclusion:Notwithstanding the lack of randomized controlled trials, synthesis of the existing body of evidence suggests a relationship between checklist use in surgery and fewer postoperative complications.

Ablation of the thyroid remnant and I-131 dose in differentiated thyroid cancer: a meta-analysis revisited.

Postoperative ablation of functioning thyroid tissue has become established in the management of differentiated thyroid cancer as the long-term risk of recurrence and death is reduced. This beneficial effect results from the destruction of potentially malignant cells or occult multifocal disease that may occur in up to 30% of patients with papillary tumors1–4 Furthermore, the specificity of thyroglobulin as a tumor marker is increased and the sensitivity of subsequent whole body scans seems improved because residual thyroid tissue may compete with recurrent or metastatic thyroid cancer cells for radioiodine uptake.5 Indeed, it has been demonstrated that patients with successful ablation of remnant thyroid tissue have a better prognosis than those with unsuccessful ablation (disease-free survival of 87% versus 49% after 10 years, while thyroid cancer-related survival was 93% versus 78%).6 This suggests that it is important to achieve complete ablation as soon as possible after diagnosis in order to ensure the best possible prognosis for a patient. n nIn 2000,7 we demonstrated that the optimal dose (specific activity of I-131 administered) required to achieve ablation is a high dose of approximately 100 mCi, and thus lower doses are not as beneficial as the conventional doses of 75 to 100 mCi (2775–3700 MBq) in terms of successful remnant ablation. Recently, Hackshaw et al8 carried out another meta-analysis including studies published since 2000, and surprisingly, report that from the published data it is not possible to reliably determine whether ablation success rates using 30 mCi are similar to using 100 mCi. Our analysis7 published in 2000 predicted that the risk estimates were stable. We did not think additional data would refute these findings, but rather would further narrow down the confidence intervals (CI) of the risk estimate. Thus, we performed this analysis again using the same data extracted by Hackshaw et al.8 n nThe methods used were the same as previously described7 and the quantification was on the dichotomous variable “risk of failure of remnant ablation after I-131.” There were a total of 2,584 patients (as opposed to our previous report which consisted of 967 patients), and of these, 1,094 patients who were given low doses and 1,490 patients who were given high doses were extracted from the 22 datasets that contained both a low-dose and high-dose group as reported in the study by Hackshaw et al.8 Of these 22 datasets, six were randomized controlled trials with mixed surgical status (group 2),9–14 four were cohorts with near-total thyroidectomy (group 1)7,15–17 and 12 were cohorts with mixed surgical status (group 3).7,18–28 Because of the concern about combining data from studies with markedly different designs, separate analyses were done for each group, as well as a pooled analysis. Since the test for heterogeneity was almost statistically significant (Cochran Q for heterogeneity, P=0.08), a random effects model was used as it does not assume that a common (fixed) treatment effect exists but rather that the true treatment effects in the individual studies may be different from each other. Such an analysis assumes the distribution of different true effects in each study is normally distributed, and we can estimate the summary of the different effects. However, we did not find a significant difference in results using a fixed or random effects model, and the CIs in the cumulative plot narrow with each additional study, suggesting that it may be reasonable to combine the studies into one stratum. n nMost studies used a high dose of 2775–3700 MBq (75–100 mCi). The summary high-dose to low-dose group relative risk (RR) of non-ablation after the first dose was 0.58 (95% CI, 0.46–0.74) for the cohort studies in group 1 and 0.88 (95% CI, 0.78–1) for those in group 3 using the random effects model. RR was 0.68 (95% CI, 0.43–1.07) for the randomized controlled trials (group 2) using the random effects model. The subgroup summary and individual study RRs and 95% CIs, listed by year of publication, are depicted individually in figure 1A ▶. A cumulative analysis is depicted in figure 1B ▶, while figure 1C ▶ displays the result of a cumulative analysis by subgroup. The pooled RR for all studies is 0.73 (95% CI, 0.62–0.85) which is identical to the risk estimate we reported previously (RR=0.73; 95% CI, 0.61–0.87).7 This indicates that despite the inclusion of additional studies from the last 7 years, and more than doubling the patient pool, these estimates remain stable and affirm our previous findings.7 Thus, we cannot agree with the findings of Hackshaw et al.8 In summary, our analyses indicate that high-dose patients have about one-third less risk of non-ablation than low-dose patients, more so if extent of surgery is near-total and less so if incomplete surgery is performed. n n n nFigure 1. n nStandard meta-analysis and cumulative meta-analysis. (A) The standard meta-analysis plot of the risk ratios for non-ablation in a comparison of high-dose radioiodine (treatment group) with low-dose radioiodine (control group). The point estimates for ... n n n nWe have not attempted here to redefine the pertinent issues in meta-analysis such as eligibility criteria, restriction of sample size or length of follow-up, eligibility based on similarity of treatments or outcomes or study quality, as these have been addressed in the original meta-analyses.7,8 Nevertheless, we must draw attention to a few important study differences that exist. The most important, as mentioned previously, is confounding caused by the extent of surgery. This, however, should bias the end result towards less effect for the high-dose group unless more patients with subtotal surgery were given lower doses. This seems unlikely as clinicians are prone to give higher doses to patients with subtotal surgery. However, as both high and low doses are less effective in less complete surgery, groups 2 and 3 demonstrate blunted risk differences. n nAn additional confounding factor would be the timing of post-ablation scans. If those patients given higher doses were scanned later than those given lower doses, a biased estimate of risk reduction could be determined. There was no reason to suspect that this had occurred in any study included in this analysis. One issue that certainly needs to be considered in the interpretation of this synthesis is the possibility of selection bias in the same direction across the studies, thus falsely exaggerating the risk estimates. In hospital-based cohort studies, it may be difficult to ensure comparability of the low-dose and high-dose groups, since selection bias as a result of unknown referral patterns cannot be easily overcome. However, we would assume that lower risk patients get lower doses and vice-versa, leading to non-differential bias resulting in a trend towards no difference rather than an exaggerated effect for higher doses. Finally, publication bias certainly may have influenced these results as indicated by Hackshaw et al,8 but this is a subject where negative results with larger doses would certainly qualify for publication due to the controversy that exists. n nWe would like to repeat our previous conclusion7 that, while it is true a higher dose means higher costs of admission to the hospital and patient inconvenience, comparing this and the rather insignificant side effects of the higher dose to that of a lower dose should focus in the first instance on an estimate of the benefits of successful ablation. Wong et al4 used a decision analytic perspective to determine that successful ablation probably reduces cancer recurrence rates by 54%, and the change in life expectancy gained by successful ablation is about equal to that gained by coronary artery bypass graft in patients with two vessel coronary artery disease. The question of cost and inconvenience with high-dose therapy is similar to the question of choice of surgeon in coronary artery bypass graft. The stage of the tumor, extent of surgery and age of the patient are all factors in this decision-making process. We conclude that after increasingly meticulous near-total surgery and careful patient selection, the available data continue to favor higher doses of radioiodine (in the region of 2775–3700 MBq) for remnant ablation, especially after near-total thyroidectomy.

Perception of the Educational Environment by Medical Students Undergoing a Curricular Transition in Kuwait

Objective: The aim of this study was to measure the students’ perceptions of the educational environment in a medical school undergoing curricular transition from a traditional to a problem-based learning (PBL) program in the academic year 2006–2007. Materials and Methods: The Dundee Ready Education Environment Measure (DREEM) was used to evaluate perception of the educational environment. Multivariate logistic regression models were used to identify the factors related to educational environment perception that differ between students following a traditional curriculum to those following a PBL program at Kuwait University Medical School. Results: Mean DREEM score was 53%. When students moved from the traditional curriculum to the PBL system, Academic Self-Perception deteriorated, while Perception of Atmosphere improved. Academic Self-Perception deteriorated because conventional strategies of learning were perceived as no longer useful, while Perception of Atmosphere improved because of increased relevance of the studies. Conclusion: Our findings suggest that curricular changes require careful planning and thinking, with particular attention upon how they influence the educational climate. When new teaching strategies are introduced, new factors that may lead students to develop an adverse perception of their educational environment may be introduced as well. Identification of such factors can lead to an improved educational outcome.

CNE Article: Safety Culture In Australian Intensive Care Units: Establishing A Baseline For Quality Improvement

BACKGROUNDnWorkplace safety culture is a crucial ingredient in patients outcomes and is increasingly being explored as a guide for quality improvement efforts.nnnOBJECTIVESnTo establish a baseline understanding of the safety culture in Australian intensive care units.nnnMETHODSnIn a nationwide study of physicians and nurses in 10 Australian intensive care units, the Safety Attitudes Questionnaire intensive care unit version was used to measure safety culture. Descriptive statistics were used to summarize the mean scores for the 6 subscales of the questionnaire, and generalized-estimation-equations models were used to test the hypotheses that safety culture differed between physicians and nurses and between nurse leaders and bedside nurses.nnnRESULTSnA total of 672 responses (50.6% response rate) were received: 513 (76.3%) from nurses, 89 (13.2%) from physicians, and 70 (10.4%) from respondents who did not specify their professional group. Ratings were highest for teamwork climate and lowest for perceptions of hospital management and working conditions. Four subscales, job satisfaction, teamwork climate, safety climate, and working conditions, were rated significantly higher by physicians than by nurses. Two subscales, working conditions and perceptions of hospital management, were rated significantly lower by nurse leaders than by bedside nurses.nnnCONCLUSIONSnMeasuring the baseline safety culture of an intensive care unit allows leaders to implement targeted strategies to improve specific dimensions of safety culture. These strategies ultimately may improve the working conditions of staff and the care that patients receive.

Simulation comparison of the quality effects and random effects methods of meta-analysis

This is an editorial note/letter on Simulation Comparison of the Quality Effects and Random Effects Methods of Metaanalysis.

An outcomes evaluation of an Australian Hospital in the Nursing Home admission avoidance programme

AIMS AND OBJECTIVESnTo undertake an outcomes evaluation of a Hospital in the Nursing Home (HINH) admission avoidance programme.nnnBACKGROUNDnAdmission avoidance type services such as Hospital in the Home have a place in improving service delivery for certain population groups. Research related to HINH has been limited, derived from various different health care systems internationally and results are varied.nnnDESIGNnA quasi-experimental study was conducted at one regional hospital. Routinely collected health information system data from two separate data sources were linked to undertake analysis.nnnMETHODSnThose in the intervention group were matched to a comparison group of patients on the basis of three characteristics (age, gender and diagnostic category). Other factors that could affect a patients hospital outcomes and length of stay (LOS) were statistically controlled for. Participants were aged care facility residents enrolled in a HINH programme (n = 62) and a matched group receiving usual in-hospital care (n = 115). Emergency department (ED) outcome measures included LOS and re-presentation. Hospital admission-related outcome measures included episode of care LOS, in-hospital LOS and hospital readmission.nnnRESULTSnA significant independent relationship between HINH programme enrolment and shorter in-hospital LOS was identified even after adjusting for other characteristics OR 0·16 (95% CI 0·28, 0·99 pu2003<u20030·001).nnnCONCLUSIONnThe HINH model evaluated, with its focus on delivering acute care for aged care facility residents, can impact on health service delivery.nnnRELEVANCE TO CLINICAL PRACTICEnWith a demonstrated reduction in in-hospital LOS, the available bed space created can be used for other patients perhaps waiting in the ED or waiting for surgery.

Simplifying the TNM System for Clinical Use in Differentiated Thyroid Cancer

PURPOSEnThe TNM stratification has been found useful at stratifying patients with differentiated thyroid carcinoma (DTC) into prognostic risk groups. However, it is cumbersome to implement clinically given the large number of bins within this system and the complicated system of arriving at stage information.nnnPATIENTS AND METHODSnWe decided to quantify each variable in this system to arrive at a simplified quantitative alternative to the TNM system (QTNM) and compare this with the conventional system. We used our electronic record system to identify 614 cases of DTC managed at our institution from 1987 to 2006. Cancer-specific survival (CSS) and disease-free survival (DFS) were calculated by the Kaplan-Meier method, and a simplified QTNM score was devised using a Cox proportional hazards model.nnnRESULTSnWe were able to quantify the TNM system as follows: 4 points each for age older than 45 years and presence of neck nodal metastases while 6 points for tumor size larger than 4 cm or extrathyroidal extension and 1 point for nonpapillary DTC. A sum of 0 to 5 points was low risk, 6 to 10 points intermediate, and 11 to 15 points high risk. Comparison with the conventional TNM system and two other systems revealed similar or better discrimination with the QTNM and this discrimination was maintained when this risk stratification was applied to a unique validation set.nnnCONCLUSIONnThe QTNM system as opposed to the conventional TNM system seems to be a simple and effective method for risk stratification for both recurrence and cancer-specific mortality.

Use of a Robotic Seal as a Therapeutic Tool to Improve Dementia Symptoms: A Cluster-Randomized Controlled Trial.

OBJECTIVESnTo test the effects of individual, nonfacilitated sessions with PARO (version 9), when compared against a look-alike plush toy and usual care, on the emotional and behavioral symptoms of dementia for people living in long-term care facilities.nnnDESIGNnParallel, 3-group, cluster-randomized controlled trial conducted between June 14, 2014, and May 16,xa02015.nnnSETTINGnTwenty-eight long-term care facilities operated by 20 care organizations located in South-East Queensland, Australia.nnnPARTICIPANTSnFour hundred fifteen participants aged ≥60xa0years, with a documented diagnosis of dementia.nnnINTERVENTIONnStratified by private/not-for-profit status and randomized using a computer-generated sequence, 9 facilities were randomized to the PARO group (individual, nonfacilitated, 15-minute sessions 3 times per week for 10xa0weeks); 10 to plush toy (same, but given PARO with robotic features disabled); and 9 to usual care. Treatment allocation was masked to assessors.nnnMEASUREMENTSnPrimary outcomes were changes in levels of engagement, mood states, and agitation after a 10-week intervention, assessed by coded video observations (baseline, weeks 1, 5, 10, and 15) and Cohen-Mansfield Agitation Inventory-Short Form (baseline, weeks 10 and 15). Analyses followed intention-to-treat, using repeated measures mixed effects models. Australian New Zealand Clinical Trials Registry (ACTRN12614000508673).nnnRESULTSnVideo data showed that participants in the PARO group were more verbally [3.61, 95% confidence interval (CI): 6.40-0.81, Pxa0=xa0.011] and visually engaged (13.06, 95% CI: 17.05-9.06, Pxa0<xa0.0001) than participants in plush toy. Both PARO (-3.09, 95% CI:xa0-0.45 toxa0-5.72, Pxa0=xa0.022) and plush toy (-3.58, 95% CI:xa0-1.26 toxa0-5.91, Pxa0=xa0.002) had significantly greater reduced neutral affect compared with usual care, whilst PARO was more effective than usual care in improving pleasure (1.12, 95% CI: 1.94-0.29, Pxa0=xa0.008). Videos showed that PARO was more effective than usual care in improving agitation (3.33, 95% CI: 5.79-0.86, Pxa0=xa0.008). When measured using the CMAI-SF, there was no difference between groups.nnnCONCLUSIONSnAlthough more effective than usual care in improving mood states and agitation, PARO was only more effective than a plush toy in encouraging engagement.

The effect of a patient centred care bundle intervention on pressure ulcer incidence (INTACT): A cluster randomised trial

BACKGROUNDnHospital-acquired pressure ulcers are a serious patient safety concern, associated with poor patient outcomes and high healthcare costs. They are also viewed as an indicator of nursing care quality.nnnOBJECTIVEnTo evaluate the effectiveness of a pressure ulcer prevention care bundle in preventing hospital-acquired pressure ulcers among at risk patients.nnnDESIGNnPragmatic cluster randomised trial.nnnSETTINGnEight tertiary referral hospitals with >200 beds each in three Australian states.nnnPARTICIPANTSn1600 patients (200/hospital) were recruited. Patients were eligible if they were: ≥18 years old; at risk of pressure ulcer because of limited mobility; expected to stay in hospital ≥48h and able to read English.nnnMETHODSnHospitals (clusters) were stratified in two groups by recent pressure ulcer rates and randomised within strata to either a pressure ulcer prevention care bundle or standard care. The care bundle was theoretically and empirically based on patient participation and clinical practice guidelines. It was multi-component, with three messages for patients participation in pressure ulcer prevention care: keep moving; look after your skin; and eat a healthy diet. Training aids for patients included a DVD, brochure and poster. Nurses in intervention hospitals were trained in partnering with patients in their pressure ulcer prevention care. The statistician, recruiters, and outcome assessors were blinded to group allocation and interventionists blinded to the study hypotheses, tested at both the cluster and patient level. The primary outcome, incidence of hospital-acquired pressure ulcers, which applied to both the cluster and individual participant level, was measured by daily skin inspection.nnnRESULTSnFour clusters were randomised to each group and 799 patients per group analysed. The intraclass correlation coefficient was 0.035. After adjusting for clustering and pre-specified covariates (age, pressure ulcer present at baseline, body mass index, reason for admission, residence and number of comorbidities on admission), the hazard ratio for new pressure ulcers developed (pressure ulcer prevention care bundle relative to standard care) was 0.58 (95% CI: 0.25, 1.33; p=0.198). No adverse events or harms were reported.nnnCONCLUSIONSnAlthough the pressure ulcer prevention care bundle was associated with a large reduction in the hazard of ulceration, there was a high degree of uncertainty around this estimate and the difference was not statistically significant. Possible explanations for this non-significant finding include that the pressure ulcer prevention care bundle was effective but the sample size too small to detect this.