Ontario health technology assessment series
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Ont Health Technol Assess Ser · Jan 2005
Deep brain stimulation for Parkinson's disease and other movement disorders: an evidence-based analysis.
To determine the effectiveness and adverse effects of deep brain stimulation (DBS) in the treatment of symptoms of idiopathic Parkinson's disease, essential tremor, and primary dystonia and to do an economic analysis if evidence for effectiveness is established. ⋯ According to the estimates of prevalence and evidence of effectiveness, there is a shortfall in the numbers of DBS currently done in Ontario for drug-resistant PD, essential tremor, and primary dystonia.Since complication rates are lower if DBS is performed in specialized centres, the number of sites should be limited.The cost per procedure to institutions with the expertise to undertake DBS and the human resource considerations are likely to be limiting factors in the further diffusion of DBS.
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Ont Health Technol Assess Ser · Jan 2005
Sacral nerve stimulation for urinary urge incontinence, urgency-frequency, urinary retention, and fecal incontinence: an evidence-based analysis.
The aim of this review was to assess the effectiveness, safety, and cost of sacral nerve stimulation (SNS) to treat urinary urge incontinence, urgency-frequency, urinary retention, and fecal incontinence. ⋯ In summary, there is level 2 evidence to support the effectiveness of SNS to treat people with urge incontinence, urgency-frequency, or urinary retention. There is level 4 evidence to support the effectiveness of SNS to treat people with fecal incontinence. To qualify for SNS, people must meet the following criteria: Be refractory to behaviour and/or drug therapyHave had a successful test stimulation before implantation; successful test stimulation is defined by a 50% or greater improvement in voiding function based on the results of a voiding diary. Test stimulation periods range from 3 to 7 days for patients with urinary dysfunctions, and from 2 to 3 weeks for patients with fecal incontinence.Be able to record voiding diary data, so that clinical results of the implantation can be evaluated.Patients with stress incontinence, urinary retention due to obstruction and neurogenic conditions (such as diabetes with peripheral nerve involvement) are ineligible for sacral nerve stimulation. Physicians will need to learn how to use the InterStim System for Urinary Control. Requirements for training include these: Physicians must be experienced in the diagnosis and treatment of lower urinary tract disorders and should be trained in the implantation and use of the InterStim System for Urinary Control. (ABSTRACT TRUNCATED)
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Ont Health Technol Assess Ser · Jan 2005
Implantable cardioverter defibrillators. Prophylactic use: an evidence-based analysis.
The use of implantable cardiac defibrillators (ICDs) to prevent sudden cardiac death (SCD) in patients resuscitated from cardiac arrest or documented dangerous ventricular arrhythmias (secondary prevention of SCD) is an insured service. In 2003 (before the establishment of the Ontario Health Technology Advisory Committee), the Medical Advisory Secretariat conducted a health technology policy assessment on the prophylactic use (primary prevention of SCD) of ICDs for patients at high risk of SCD. The Medical Advisory Secretariat concluded that ICDs are effective for the primary prevention of SCD. Moreover, it found that a more clearly defined target population at risk for SCD that would be likely to benefit from ICDs is needed, given that the number needed to treat (NNT) from recent studies is 13 to 18, and given that the per-unit cost of ICDs is $32,000, which means that the projected cost to Ontario is $770 million (Cdn). Accordingly, as part of an annual review and publication of more recent articles, the Medical Advisory Secretariat updated its health technology policy assessment of ICDs. ⋯ Using the GRADE Working Group criteria, the quality of these 3 trials was examined (Table 2). Quality refers to the criteria such as the adequacy of allocation concealment, blinding and follow-up. Consistency refers to the similarity of estimates of effect across studies. If there is important unexplained inconsistency in the results, our confidence in the estimate of effect for that outcome decreases. Differences in the direction of effect, the size of the differences in effect, and the significance of the differences guide the decision about whether important inconsistency exists. Directness refers to the extent to which the people interventions and outcome measures are similar to those of interest. For example, there may be uncertainty about the directness of the evidence if the people of interest are older, sicker or have more comorbidity than those in the studies. As stated by the GRADE Working Group, the following definitions were used to grade the quality of the evidence: HIGH: Further research is very unlikely to change our confidence n the estimate of effect.MODERATE: Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate.LOW: Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate.VERY LOW: Any estimate of effect is very uncertain.Table 2:Quality of Evidence - MADIT I, MADIT II, and SCD-HeFT*TrialDesignQualityConsistencyDirectness†Quality GradeMADIT IRCTImbalance in β-blocker usage between study arms.The overall number of patients from which the study was drawn was not reported.Selection bias may have occurred since patients were selected for randomization if they did not respond to procainamide, thereby introducing a potential bias into the medication arm.Specific details regarding allocation concealment and blinding procedures were not provided.Single-chamber ICD used in study.Trial started with transthoracic implants, and then switched to nontransthoracic implants.Ischemic cardiomyopathy only.5-year NNT = 2.The overall number of Moderate patients from which the study was drawn was not reported.Selection bias may have occurred since patients were selected for randomization if they did not respond to procainamide, thereby introducing a potential bias into the medication arm.ModerateMADIT IIRCT~ 90% of patients were recruited ≥6 months post-MI; 20% of control group died after mean 20-month follow-up.How and where patients recruited?Specific details regarding allocation concealment/blinding procedures not provided.Subset had MADIT I criteria; post hoc analysis of incomplete data suggested "weak-moderate evidence that ICD effect greater in inducible than noninducible patients in MADIT II." (5;6)First study to assess both single- and dual-chamber ICD devices for primary prevention.Programming of device and medications left to the discretion of the patients' physician.Higher rate of hospitalization for new or worsened heart failure in the group receiving the ICDs compared to conventional therapy (19.9% versus 14.9% respectively).Ischemic cardiomyopathy only.5-year NNT = 6.How and where patients Weak recruited?Subset had MADIT I criteria.WeakSCD-HeFTRCTStatistically significant difference in β-blocker usage between treatment groups at last follow-up.Drug arms double-blinded.Shock-only single-lead device. Antitachycardia pacing not permitted.Ischemic and nonischemic cardiomyopathy.There was a statistically significant difference in terms of the NYHA prespecified subgroups analysis. The NYHA subgroups were prespecified a priori and the results of the interaction tests were significant. Yet, ICD treatment had a significant benefit in patients in NYHA class II but not in those in NYHA class III. (ABSTRACT TRUNCATED)
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Ont Health Technol Assess Ser · Jan 2005
Use of automated external defibrillators in cardiac arrest: an evidence-based analysis.
The objectives were to identify the components of a program to deliver early defibrillation that optimizes the effectiveness of automated external defibrillators (AEDs) in out-of-hospital and hospital settings, to determine whether AEDs are cost-effective, and if cost-effectiveness was determined, to advise on how they should be distributed in Ontario. ⋯ The OPALS study model appears cost-effective, and effectiveness can be further enhanced by training community volunteers to improve the bystander-initiated CPR rates. Deployment of AEDs in all public access areas and in houses and apartments is not cost-effective. Further research is needed to examine the benefit of in-home use of AEDs in patients at high risk of cardiac arrest.
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Ont Health Technol Assess Ser · Jan 2005
Osteogenic protein-1 for long bone nonunion: an evidence-based analysis.
To assess the efficacy of osteogenic protein-1 (OP-1) for long bone nonunion. ⋯ Friedlaender et al. conducted a prospective, randomized, partially blinded clinical trial on the treatment tibial nonunions with OP-1. Tibial nonunions were chosen for this study because of their high frequency, challenging treatment requirements, and substantial morbidity. All of the nonunions were at least 9 months old and had shown no progress toward healing over the previous 3 months. The patients were randomized to receive either treatment with autologous bone grafting or treatment with OP-1 in a type-1 collagen carrier. Both groups received reduction and fixation with an intramedullary rod. Table 1 summarizes the clinical outcomes of this study. Table 1:Outcomes in a Randomized Clinical Trial on Tibial Nonunions: Osteogenic Protein-1 versus Autologous Bone GraftingClinical Indicator at 9 monthsSuccess by ProcedureOP-1 % (range)Autograft % (range)PWeight-bearing*8685not significantPain on Weight-bearing*8990not significantBridging seen on radiograph (at least 1 view)7584not significantBridging seen on radiograph (at least 3 views)6274not significantRepeated surgery*510not significantPhysician satisfaction8690not significantMean operative time in minutes (range)169 (58 - 420)178 (58 - 420)not significantMean operative blood loss in ml (range)254 (10-1,150)345 (35 - 1,200).049Mean length of stay in days (range)3.7 (0 - 18)4.1 (1 - 24)not significantPain at the donor siteN/A80N/AAt 6 months postsurgery20At 12 months postsurgery13Osteomyelitis % (number)3 (2/61)21 (13/61). (ABSTRACT TRUNCATED)