Twelve recommendations for integrating existing systematic reviews into new reviews: EPC guidance.

OBJECTIVES: As time and cost constraints in the conduct of systematic reviews increase, the need to consider the use of existing systematic reviews also increases. We developed guidance on the integration of systematic reviews into new reviews. METHODS: A workgroup of methodologists from Evidence-based Practice Centers developed consensus-based recommendations. Discussions were informed by a literature scan and by interviews with organizations that conduct systematic reviews. RESULTS: Twelve recommendations were developed addressing selecting reviews, assessing risk of bias, qualitative and quantitative synthesis, and summarizing and assessing body of evidence. CONCLUSIONS: We provide preliminary guidance for an efficient and unbiased approach to integrating existing systematic reviews with primary studies in a new review.

Integration of existing systematic reviews into new reviews: identification of guidance needs.

BACKGROUND: An exponential increase in the number of systematic reviews published, and constrained resources for new reviews, means that there is an urgent need for guidance on explicitly and transparently integrating existing reviews into new systematic reviews. The objectives of this paper are: 1) to identify areas where existing guidance may be adopted or adapted, and 2) to suggest areas for future guidance development. METHODS: We searched documents and websites from healthcare focused systematic review organizations to identify and, where available, to summarize relevant guidance on the use of existing systematic reviews. We conducted informational interviews with members of Evidence-based Practice Centers (EPCs) to gather experiences in integrating existing systematic reviews, including common issues and challenges, as well as potential solutions. RESULTS: There was consensus among systematic review organizations and the EPCs about some aspects of incorporating existing systematic reviews into new reviews. Current guidance may be used in assessing the relevance of prior reviews and in scanning references of prior reviews to identify studies for a new review. However, areas of challenge remain. Areas in need of guidance include how to synthesize, grade the strength of, and present bodies of evidence composed of primary studies and existing systematic reviews. For instance, empiric evidence is needed regarding how to quality check data abstraction and when and how to use study-level risk of bias assessments from prior reviews. CONCLUSIONS: There remain areas of uncertainty for how to integrate existing systematic reviews into new reviews. Methods research and consensus processes among systematic review organizations are needed to develop guidance to address these challenges.

Risk of bias versus quality assessment of randomised controlled trials: cross sectional study.

OBJECTIVES: To evaluate the risk of bias tool, introduced by the Cochrane Collaboration for assessing the internal validity of randomised trials, for inter-rater agreement, concurrent validity compared with the Jadad scale and Schulz approach to allocation concealment, and the relation between risk of bias and effect estimates. DESIGN: Cross sectional study. Study sample 163 trials in children. MAIN OUTCOME MEASURES: Inter-rater agreement between reviewers assessing trials using the risk of bias tool (weighted kappa), time to apply the risk of bias tool compared with other approaches to quality assessment (paired t test), degree of correlation for overall risk compared with overall quality scores (Kendall's tau statistic), and magnitude of effect estimates for studies classified as being at high, unclear, or low risk of bias (metaregression). RESULTS: Inter-rater agreement on individual domains of the risk of bias tool ranged from slight (kappa=0.13) to substantial (kappa=0.74). The mean time to complete the risk of bias tool was significantly longer than for the Jadad scale and Schulz approach, individually or combined (8.8 minutes (SD 2.2) per study v 2.0 (SD 0.8), P<0.001). There was low correlation between risk of bias overall compared with the Jadad scores (P=0.395) and Schulz approach (P=0.064). Effect sizes differed between studies assessed as being at high or unclear risk of bias (0.52) compared with those at low risk (0.23). CONCLUSIONS: Inter-rater agreement varied across domains of the risk of bias tool. Generally, agreement was poorer for those items that required more judgment. There was low correlation between assessments of overall risk of bias and two common approaches to quality assessment: the Jadad scale and Schulz approach to allocation concealment. Overall risk of bias as assessed by the risk of bias tool differentiated effect estimates, with more conservative estimates for studies at low risk.

Cardiac resynchronization therapy and implantable cardiac defibrillators in left ventricular systolic dysfunction.

OBJECTIVES: To determine the efficacy, effectiveness, and safety of cardiac resynchronization therapy (CRT) and/or implantable cardioverter defibrillators (ICD) in patients with left ventricular systolic dysfunction (LVSD). DATA SOURCES: A systematic and comprehensive literature search was conducted to identify randomized controlled trials (RCTs) evaluating efficacy and observational studies evaluating effectiveness or safety of CRT and/or ICD in patients with LVSD. REVIEW METHODS: Study selection, quality assessment, and data extraction were completed by several investigators in duplicate and independently. Random-effects models were used for analyses. RESULTS: From 11,340 citations, we identified 14 RCTs (4,420 patients) for the CRT efficacy review, 106 studies (9,209 patients) for the CRT effectiveness review, 89 studies (9,677 patients) for the CRT safety review, 12 RCTs (8,516 patients) for the ICD efficacy review, 48 studies (15,097 patients) for the ICD effectiveness review, and 49 studies (12,592 patients) for the ICD safety review-all studies enrolled only patients with LVSD. An additional 12 studies (68,848 patients) were included for an analysis of peri-implant outcomes for all patients with ICD (i.e., not only LVSD patients). All patients in the CRT studies had LVSD (mean LVEF from 21 to 30 percent) and prolonged QRS duration (mean from 155 to 209 msec), and 91 percent had New York Heart Association (NYHA) class III or IV symptoms. In patients with LVSD and heart failure symptoms, CRT improved ejection fraction (weighted mean difference 3.0 percent [95% CI, 0.9 to 5.1]), quality of life (weighted mean reduction in Minnesota Living with Heart Failure Questionnaire 8.0 points [95% CI, 5.6 to 10.4 points]), and function (59 percent of CRT recipients vs. 37 percent of controls improved by at least one NYHA class in the RCTs and between 63 percent and 82 percent of CRT recipients improved by at least one NYHA class in observational studies). The proportion of patients hospitalized for HF was reduced by 37 percent (95% CI, 7 to 57 percent) and all-cause mortality was reduced by 22 percent (95% CI, 9 to 33 percent; NNT=29 over 6 months). Implant success rate was 93 percent, 0.3 percent of patients with LVSD died during implantation. Over a median 11-month followup, 6.6 percent of CRT devices exhibited lead problems and 5 percent malfunctioned. In patients with LVSD, ICD reduced all-cause mortality by 20 percent (95% CI, 10 to 29 percent; NNT=20 over 35 months). ICD implant success rate was 99 percent and peri-implant deaths occurred in 1.2 percent of LVSD patients and 1.3 percent of all implantees. The frequency of post-implantation complications in LVSD patients per 100 patient years included 1.4 (95% CI, 1.2 to 1.6) device malfunctions, 1.5 (95% CI, 1.3 to 1.8) lead problems, 0.6 (95% CI, 0.5 to 0.8) implant site infections, and 19.1 (95% CI, 16.5 to 22.0) inappropriate discharges in RCT participants and 4.7 (95% CI, 4.3 to 5.1) inappropriate discharges in patients enrolled in observational studies. CONCLUSIONS: ICD and CRT reduce all-cause mortality in patients with LVSD meeting RCT entry criteria. The incremental benefit of CRT plus ICD over CRT alone in patients with LVSD remains uncertain. None of the trials reported differences in the efficacy of CRT or ICD across patient subgroups, nor did our meta-regression detect any subgroup effects; however, subgroup analyses and meta-regression using aggregate trial data are post-hoc analyses and were underpowered to detect such effects. Examination of individual patient trial data is urgently needed to define which clinical subgroups are most likely to benefit from these devices.

Direct health care costs after traumatic spinal cord injury.

BACKGROUND: The objective was to quantify direct health care costs attributable to traumatic spinal cord injury (SCI). METHODS: This population-based cohort study followed individuals with SCI from date of injury to 6 years postinjury. SCI cases were matched to a comparison group randomly selected from the general population. Administrative data from a Canadian province with a universal publicly funded health care system and centralized health databases were used. Costs included hospitalizations, physician services, home care, and long-term care. RESULTS: Attributable costs in the first year were $121,600 (2002 $CDN) per person with a complete SCI, and $42,100 per person with an incomplete injury. In the subsequent 5 years, annual costs were $5,400 and $2,800 for persons with complete and incomplete SCIs, respectively. CONCLUSION: Direct costs in the first year after SCI are substantial. In the subsequent 5 years, individuals with SCI will continue to accrue greater costs than the general public.