Endoscopic sinus surgery for the excision of nasal polyps: A systematic review of safety and effectiveness.

BACKGROUND: Functional endoscopic sinus surgery (FESS) has been used for >20 years for the management of sinus disease including the excision of nasal polyps. Our objective was to perform a systematic review of safety and effectiveness of FESS for the removal of nasal polyps. METHODS: The Cochrane Library, MEDLINE, Embase, Science Citation Index, other databases, and websites were searched in January and December 2005 using key words for nasal polyps and endoscopic surgery. All randomized controlled trials, nonrandomized comparative studies, and case series studies that described outcomes associated with FESS for the excision of nasal polyps were included. Forty-two publications were included from the 632 (6.6%) articles initially identified. Two reviewers assessed validity of included studies and extracted relevant data. RESULTS: Three randomized controlled trials, 4 nonrandomized comparative studies, and 35 case series studies were included in the review. FESS was compared with endoscopic polypectomy, Caldwell-Luc, radical nasalization, and intranasal ethmoidectomy. In general, studies were of poor quality and lacked description of important variables influencing surgical outcome. Overall complications for FESS from case series studies ranged from 0.3 to 22.4% (median, 7.0%). Major complications ranged from 0 to 1.5% (median, 0%) and minor complications ranged from 1.1 to 20.8% (median, 7.5%). The potentially most serious complications were cerebrospinal fluid leaks, injury to the internal carotid artery, dural exposure, meningitis, bleeding requiring transfusion, periorbital/orbital fat exposure, and orbital penetration. Symptomatic improvement ranged from 78 to 88% for FESS compared with 43 to 84% for comparative procedures. From case series, symptomatic improvement ranged from 40 to 98% (median, 88%). CONCLUSION: FESS may offer some advantages in safety and effectiveness over comparative techniques, but wide variation in reported results and methodological shortcomings of studies limit the certainty of these conclusions. Wide variation in complication rates suggests the need for audit of existing practice. Additional high-quality studies with a fuller description of potential confounding factors and effect modifiers will help to define the effectiveness of FESS more clearly.

Impact of discussion on preferences elicited in a group setting.

BACKGROUND: The completeness of preferences is assumed as one of the axioms of expected utility theory but has been subject to little empirical study. METHODS: Fifteen non-health professionals was recruited and familiarised with the standard gamble technique. The group then met five times over six months and preferences were elicited independently on 41 scenarios. After individual valuation, the group discussed the scenarios, following which preferences could be changed. Changes made were described and summary measures (mean and median) before and after discussion compared using paired t test and Wilcoxon Signed Rank Test. Semi-structured telephone interviews were carried out to explore attitudes to discussing preferences. These were transcribed, read by two investigators and emergent themes described. RESULTS: Sixteen changes (3.6%) were made to preferences by seven (47%) of the fifteen members. The difference between individual preference values before and after discussion ranged from -0.025 to 0.45. The average effect on the group mean was 0.0053. No differences before and after discussion were statistically significant. The group valued discussion highly and suggested it brought four main benefits: reassurance; improved procedural performance; increased group cohesion; satisfying curiosity. CONCLUSION: The hypothesis that preferences are incomplete cannot be rejected for a proportion of respondents. However, brief discussion did not result in substantial number of changes to preferences and these did not have significant impact on summary values for the group, suggesting that incompleteness, if present, may not have an important effect on cost-utility analyses.

Association between methodological characteristics and outcome in health technology assessments which included case series.

OBJECTIVES: Case series constitute a weak form of evidence for effectiveness of health technologies. However, for a variety of reasons, such studies may be included in health technology assessments. There are no clear criteria for assessing the quality of case series. We carried out an empirical investigation of the association between outcome frequency and methodological characteristics in a sample of health technology assessments. METHODS: Systematic reviews of functional endoscopic sinus surgery for nasal polyps, spinal cord stimulation for chronic back pain, and percutaneous transluminal coronary angioplasty and coronary artery bypass grafting for chronic stable angina were identified as containing more than forty case series. Data were extracted by one reviewer and checked by a second on population characteristics, outcomes, and the following methodological features: sample size, prospective/retrospective approach, consecutive recruitment, multi- or single-center organization, length of follow-up, independence of outcome measurement, and date of publication. Association between methodological features and outcome were explored in univariate and multivariate analyses using parametric and nonparametric tests and robust regression or analysis of variance/analysis of covariance, as appropriate. RESULTS: Included reviews contained between forty-two and seventy-six case series studies, involving 5 to 172,283 participants. Reporting of methodological features was poor and limited the analyses. In general, we found little evidence of any association between methodological characteristics and outcome. Sample size is used as an inclusion criterion in many reviews of'case series but was consistently shown to have no relationship to outcome in all analyses. A prospective approach was not associated with outcome. Insufficient data were available to explore consecutive recruitment. Mixed results were shown for length of follow-up, independence of outcome measurement, and publication date. CONCLUSIONS: We found little evidence to support the use of many of the factors included in tools used for quality assessment of case series. Importantly, we found no relationship between study size and outcome across the four examples studied. Isolated examples of a potentially important relationship between other methodological factors and outcome were shown, for example, blinding of outcome measurement, but these examples were not shown consistently across the small number of examples studied. Further research into the determinants of quality in case series studies is required to support health technology assessment.

Cost effectiveness of imatinib compared with interferon-alpha or hydroxycarbamide for first-line treatment of chronic myeloid leukaemia.

OBJECTIVE: To evaluate the cost utility of imatinib compared with interferon (IFN)-alpha or hydroxycarbamide (hydroxyurea) for first-line treatment of chronic myeloid leukaemia. DESIGN AND SETTING: A cost-utility (Markov) model within the setting of the UK NHS and viewed from a health system perspective was adopted. Transition probabilities and relative risks were estimated from published literature. Costs of drug treatment, outpatient care, bone marrow biopsies, radiography, blood transfusions and inpatient care were obtained from the British National Formulary and local hospital databases. Costs (pound, year 2001-03 values) were discounted at 6%. Quality-of-life (QOL) data were obtained from the published literature and discounted at 1.5%. The main outcome measure was cost per QALY gained. Extensive one-way sensitivity analyses were performed along with probabilistic (stochastic) analysis. RESULTS: The incremental cost-effectiveness ratio (ICER) of imatinib, compared with IFNalpha, was pound26,180 per QALY gained (one-way sensitivity analyses ranged from pound19,449 to pound51,870) and compared with hydroxycarbamide was pound86,934 per QALY (one-way sensitivity analyses ranged from pound69,701 to pound147,095) [ pound1=$US1.691=euro1.535 as at 31 December 2002].Based on the probabilistic sensitivity analysis, 50% of the ICERs for imatinib, compared with IFNalpha, fell below a threshold of approximately pound31,000 per QALY gained. Fifty percent of ICERs for imatinib, compared with hydroxycarbamide, fell below approximately pound95,000 per QALY gained. CONCLUSIONS: This model suggests, given its underlying data and assumptions, that imatinib may be moderately cost effective when compared with IFNalpha but considerably less cost effective when compared with hydroxycarbamide. There are, however, many uncertainties due to the lack of long-term data.

Microwave and thermal balloon ablation for heavy menstrual bleeding: a systematic review.

OBJECTIVE: To compare the effectiveness of two second generation endometrial ablation techniques (microwave and thermal balloon endometrial ablation) with first generation techniques of endometrial ablation to treat heavy menstrual bleeding in women. SEARCH STRATEGY: We searched the Cochrane Library (issue 3, 2002), the National Research Register, MEDLINE (1966 to August 2002), Embase (1980 to August 2002) and Web of Science Proceedings (all years). We also searched reference lists and contacted experts and manufacturers in the field. SELECTION CRITERIA: Randomised controlled trials and controlled trials of microwave endometrial ablation and thermal balloon endometrial ablation versus transcervical resection and rollerball ablation, alone or in combination, to treat heavy menstrual bleeding were included. DATA COLLECTION AND ANALYSIS: Two reviewers independently selected studies for inclusion and extracted data. As there was considerable clinical and methodological heterogeneity among the studies, meta-analysis was not undertaken and results are presented descriptively. RESULTS: Two randomised controlled trials of microwave endometrial ablation and eight trials (six randomised controlled trials) of thermal balloon endometrial ablation were included in the review. No significant differences were found between first and second generation techniques in terms of amenorrhoea, bleeding patterns, pre-menstrual symptoms, patient satisfaction or quality of life. Microwave endometrial ablation and thermal balloon endometrial ablation had significantly shorter operating and theatre times than first generation techniques. Adverse effects were few with all techniques, but there were fewer peri-operative adverse effects with second generation techniques. CONCLUSION: Microwave endometrial ablation and thermal balloon endometrial ablation are alternatives to first generation techniques for treating heavy menstrual bleeding. No head-to-head trials of microwave endometrial ablation and thermal balloon endometrial ablation have been undertaken and there is not yet enough evidence of differences in clinical effectiveness between these two techniques.

What value health?: A review of health state values used in early technology assessments for NICE.

The objective of this article was to review the methods used to obtain quality-of-life (utility) weights reported in assessments carried out for the National Institute for Health and Clinical Excellence (NICE).The design of the review was a cross-sectional survey. Health technology assessment (HTA) reports published on the NICE website up to May 2003 were reviewed. Data were extracted on the following: the approach to utility estimation (direct or indirect), how health states were described for indirect estimation, valuation techniques used (standard gamble [SG], time trade-off [TTO], visual analogue scale [VAS], etc.), whether uncertainty in utility estimates was explored in cost-utility analyses, and whether utility values were identified as a priority for further research by assessment authors.Fifty-six assessments were reviewed, of which 28 reported 45 cost-utility analyses. There was striking variation in the values used to describe different health states. Data from patients were used in 15 (33%) analyses, from the general public in 10 (22%) and from clinicians in 4 (9%). In 16 (36%) cases, the source for utility estimates was unclear. Health states were described using a range of generic and disease-specific measures, although the EQ-5D was used most frequently. In 25 analyses (56%), the valuation technique used was not reported. TTO was used in 11 (24%), SG in 3 (7%), magnitude estimation in 5 (11%) and VAS in 1 (2%). Sensitivity analyses based on utility values were reported in 25 cases (56%), more commonly in reports of analyses carried out by independent teams than technology sponsors although this may be subject to reporting bias. Further research into quality of life was recommended in 17 (61%) of the 28 assessment reports that contained at least one cost-utility analysis. Greater transparency and consistency are required in reporting the methods used to obtain quality-of-life weights in cost-utility analyses, and better sources of data are required. Methodological variation results in important differences in values. Therefore, caution must be exercised when comparing the results of different cost-utility analyses.

A cost-utility analysis of microwave and thermal balloon endometrial ablation techniques for the treatment of heavy menstrual bleeding.

OBJECTIVE: To assess the cost effectiveness of the second-generation surgical treatments for heavy menstrual bleeding (microwave and thermal balloon endometrial ablation) compared with existing endometrial ablation techniques (transcervical resection and rollerball, alone or in combination) and hysterectomy. DESIGN: A state transition (Markov) cost-utility economic model. POPULATION: Women with heavy menstrual bleeding. METHODS: A Markov model was developed using spreadsheet software. Transition probabilities, costs and quality of life data were obtained from a systematic review of effectiveness undertaken by the authors, from published sources, and expert opinion. Cost data were obtained from the literature and from a NHS trust hospital. Indirect comparison of thermal balloon endometrial ablation versus microwave endometrial ablation or either second-generation endometrial ablation method versus hysterectomy, and comparison of second-generation versus first-generation techniques were carried out from the perspective of health service payers. The effects of uncertainty were explored through extensive one-way sensitivity analyses and Monte Carlo simulation. MAIN OUTCOME MEASURES: Incremental cost effectiveness ratios based on cost per quality adjusted life year (QALY) gained, and cost effectiveness acceptability curves. RESULTS: Compared with first-generation techniques, both microwave and thermal balloon endometrial ablation cost less and accrued more QALYs. Hysterectomy was more expensive, but accrued more QALYs than all endometrial ablation methods. Baseline results showed that differences between microwave endometrial ablation and thermal balloon endometrial ablation were slight. Sensitivity analyses showed that small changes in values may have a marked effect on cost effectiveness. Probabilistic simulation highlighted the uncertainty in comparisons between different endometrial ablation options, particularly between second-generation techniques. CONCLUSIONS: Despite limitations in available data, the analysis suggests that second-generation techniques are likely to be more cost effective than first-generation techniques in most cases. Hysterectomy, where a woman finds this option acceptable, continues to be a very cost effective procedure compared with all endometrial ablation methods.