Corneal higher-order aberrations after Descemet's membrane endothelial keratoplasty

PURPOSE

We compared corneal higher-order aberrations (HOAs) in eyes after Descemet's membrane endothelial keratoplasty (DMEK), Descemet's stripping automated endothelial keratoplasty (DSAEK), and penetrating keratoplasty (PK), and in a control group that had not undergone surgery.

DESIGN

Retrospective analysis of clinical data.

PARTICIPANTS

Thirty eyes of 30 patients who had undergone standard DMEK, 20 eyes of 20 patients after DSAEK, 20 eyes of 20 patients after PK, and 20 eyes of 20 controls were analyzed.

METHODS

In addition to standard postoperative examinations, each participant was analyzed with the Pentacam high-resolution rotating Scheimpflug imaging system (Pentacam HR, Oculus, Wetzlar, Germany). Data were compared between groups.

MAIN OUTCOME MEASURES

Visual acuity and HOAs.

RESULTS

The mean follow-up was 6.5 ± 1.2 months after DMEK, 22.6 ± 11.8 months after DSAEK, and 103.1 ± 74.2 months after PK. There were no statistically significant differences for the anterior 4.0-mm zones between the DMEK group and the controls or between the DMEK and DSAEK groups. The DMEK procedure compared with PK showed statistically significant differences in all terms for the 4.0-mm zones. All combined Zernike terms for mean posterior aberrations of the central 4.0-mm zones showed statistically significant higher aberrations for DMEK compared with controls. The DMEK procedure compared with DSAEK showed statistically significant lower mean values for all combined Zernike terms, except for coma and coma-like terms in the central 4.0-mm zones of the posterior corneal surface. Compared with PK, DMEK showed statistically significant lower mean values for all combined Zernike terms for the central 4.0-mm zones of the posterior corneal surface, except for spherical aberration (SA) and SA-like terms. Best spectacle-corrected visual acuity (BSCVA) after DMEK was statistically significantly better than after DSAEK (P=0.001) and PK (P=0.005). There was no statistically significant difference when BSCVA was compared with controls (P=0.998).

CONCLUSIONS

Both DSAEK and PK exhibit increased posterior corneal HOAs even years after surgery. Patients receiving DMEK display only slight changes in posterior corneal HOAs.

The cost-effectiveness of adjuvant chemotherapy for early breast cancer: A comparison of no chemotherapy and first, second, and third generation regimens for patients with differing prognoses

BACKGROUND

The risk of recurrence following surgery in women with early breast cancer varies, depending upon prognostic factors. Adjuvant chemotherapy reduces this risk; however, increasingly effective regimens are associated with higher costs and toxicity profiles, making it likely that different regimens may be cost-effective for women with differing prognoses. To investigate this we performed a cost-effectiveness analysis of four treatment strategies: (1) no chemotherapy, (2) chemotherapy using cyclophosphamide, methotrexate, and fluorouracil (CMF) (a first generation regimen), (3) chemotherapy using Epirubicin-CMF (E-CMF) or fluorouracil, epirubicin, and cyclophosphamide (FEC60) (a second generation regimens), and (4) chemotherapy with FEC60 followed by docetaxel (FEC-D) (a third generation regimen). These adjuvant chemotherapy regimens were used in three large UK-led randomised controlled trials (RCTs).

METHODS

A Markov model was used to simulate the natural progression of early breast cancer and the impact of chemotherapy on modifying this process. The probability of a first recurrent event within the model was estimated for women with different prognostic risk profiles using a parametric regression-based survival model incorporating established prognostic factors. Other probabilities, treatment effects, costs and quality of life weights were estimated primarily using data from the three UK-led RCTs, a meta-analysis of all relevant RCTs, and other published literature. The model predicted the lifetime costs, quality adjusted life years (QALYs) and cost-effectiveness of the four strategies for women with differing prognoses. Sensitivity analyses investigated the impact of uncertain parameters and model assumptions.

FINDINGS

For women with an average to high risk of recurrence (based upon prognostic factors and any other adjuvant therapies received), FEC-D appeared most cost-effective assuming a threshold of £20,000 per QALY for the National Health Service (NHS). For younger low risk women, E-CMF/FEC60 tended to be the optimal strategy and, for some older low risk women, the model suggested a policy of no chemotherapy was cost-effective. For no patient group was CMF chemotherapy the preferred option. Sensitivity analyses demonstrated cost-effectiveness results to be particularly sensitive to the treatment effect estimate for FEC-D and the future price of docetaxel.

INTERPRETATION

To our knowledge, this analysis is the first cost-effectiveness comparison of no chemotherapy, and first, second, and third generation adjuvant chemotherapy regimens for early breast cancer patients with differing prognoses. The results demonstrate the potential for different treatment strategies to be cost-effective for different types of patients. These findings may prove useful for policy makers attempting to formulate cost-effective treatment guidelines in the field of early breast cancer.

Etanercept, infliximab and adalimumab for the treatment of psoriatic arthritis: a systematic review and economic evaluation

BACKGROUND

Etanercept, infliximab and adalimumab are licensed in the UK for the treatment of active and progressive psoriatic arthritis (PsA) in adults who have an inadequate response to standard treatment.

OBJECTIVE

To determine the clinical effectiveness, safety and cost-effectiveness of these biologic agents in the treatment of active and progressive PsA.

DATA SOURCES

Systematic reviews were performed, with data sought from 10 electronic databases (MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, Science Citation Index, Conference Proceedings Citation Index - Science, ClinicalTrials.gov, metaRegister of Current Controlled Trials, NHS Economic Evaluation Database, Health Economic Evaluations Database and EconLit) up to June 2009.

REVIEW METHODS

Full paper manuscripts of titles/abstracts considered relevant were obtained and assessed for inclusion by two reviewers according to criteria on study design, interventions, participants and outcomes. Data on study and participant characteristics, efficacy outcomes, adverse effects, costs to the health service and cost-effectiveness were extracted, along with baseline data where reported. The primary efficacy outcomes were measures of anti-inflammatory response, skin lesion response and functional status, and the safety outcome was the incidence of serious adverse events. The primary measure of cost-effectiveness was incremental cost per additional quality-adjusted life-year (QALY). Standard meta-analytic techniques were applied to efficacy data. Published cost-effectiveness studies and the economic analyses submitted to the National Institute for Health and Clinical Excellence (NICE) by the biologic manufacturers were reviewed. An economic model was developed by updating the model produced by the York Assessment Group for the previous NICE appraisal of biologics in PsA.

RESULTS

Pooled estimates of effect demonstrated a significant improvement in patients with PsA for all joint disease and functional status outcomes at 12-14 weeks' follow-up. The biologic treatment significantly reduced joint symptoms for etanercept [relative risk (RR) 2.60, 95% confidence interval (CI) 1.96 to 3.45], infliximab (RR 3.44, 95% CI 2.53 to 4.69) and adalimumab (RR 2.24, 95% CI 1.74 to 2.88), with 24-week data demonstrating maintained treatment effects. Trial data demonstrated a significant effect of all three biologics on skin disease at 12 or 24 weeks. Evidence synthesis found that infliximab appeared to be most effective across all outcomes of joint and skin disease. The response in joint disease was greater with etanercept than with adalimumab, whereas the response in skin disease was greater with adalimumab than with etanercept, although these differences are not statistically significant. Under base-case assumptions, etanercept was the most likely cost-effective strategy for patients with PsA and mild-to-moderate psoriasis if the threshold for cost-effectiveness was £20,000 or £30,000 per QALY. All biologics had a similar probability of being cost-effective for patients with PsA and moderate-to-severe psoriasis at a threshold of £20,000 per QALY.

LIMITATIONS

Limited available efficacy data and difficulty in assessing PsA activity and its response to biologic therapy.

CONCLUSIONS

The data indicated that etanercept, infliximab and adalimumab were efficacious in the treatment of PsA compared with placebo, with beneficial effects on joint symptoms, functional status and skin. Short-term data suggested that these biologic agents can delay joint disease progression and evidence to support their use in the treatment of PsA is convincing. Future research would benefit from long-term observational studies with large sample sizes of patients with PsA to demonstrate that beneficial effects are maintained, along with further monitoring of the safety profiles of the biologic agents.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Golimumab for the treatment of psoriatic arthritis

This paper presents a summary of the evidence review group (ERG) report into the use of golimumab for the treatment of psoriatic arthritis (PsA). The main clinical effectiveness data were derived from a single phase III randomised controlled trial (RCT: GO-REVEAL) that compared golimumab with placebo for treating patients with active and progressive PsA who were symptomatic despite the use of previous disease-modifying antirheumatic drugs or non-steroidal anti-inflammatory drugs. The 14-week data showed that, compared with placebo, golimumab 50 mg significantly improved joint disease response as measured by American College of Rheumatology (ACR) 20 [relative risk (RR) 5.73, 95% confidence interval (CI) 3.24 to 10.56] and Psoriatic Arthritis Response Criteria (PsARC) (RR 3.45, 95% CI 2.49 to 4.87), and skin disease response as measured by the Psoriasis Area and Severity Index (PASI) 75 (RR 15.95, 95% CI 4.62 to 59.11). The 24-week absolute data showed that these treatment benefits were maintained. There was a significant improvement in patients’ functional status as measured by the Health Assessment Questionnaire (HAQ) change from baseline at 24 weeks (–0.33, p < 0.001). The open-label extension data showed that these beneficial effects were also maintained at 52 and 104 weeks. However, PASI 50 and PASI 90 at 14 weeks, and all of the PASI outcomes at 24 weeks, were not performed on the basis of intention-to-treat analysis. Furthermore, analyses of the 24-week data were less robust, failing to adjust for treatment contamination due to patient crossover at week 16. The manufacturer conducted a mixed treatment comparison (MTC) analysis. The ERG considered the assumption of exchangeability between the trials for the purpose of the MTC analysis to be acceptable, and the statistical approach in the MTC analysis to be reliable. Regarding the safety evaluation of golimumab, the manufacturer failed to provide longer-term data or to consider adverse event data of golimumab from controlled studies in other conditions, such as rheumatoid arthritis and ankylosing spondylitis. Although the adverse effect profile of golimumab appears similar to other anti-tumour necrosis factor (TNF) agents, the longer-term safety profile of golimumab remains uncertain. The manufacturer’s submission presented a decision model to compare etanercept, infliximab, golimumab and adalimumab versus palliative care for patients with PsA. In the base-case model, 73% of the cohort of patients were assumed to have significant psoriasis (> 3% of body surface area). Estimates of the effectiveness of anti-TNF agents in terms of PsARC, HAQ change and PASI change were obtained from an MTC analysis of RCT data. The manufacturer failed to calculate incremental cost-effectiveness ratios (ICERs) correctly by comparing golimumab with palliative care instead of the most cost-effective alternative (etanercept). Despite the manufacturer’s claim that golimumab is a cost-effective treatment option, the manufacturer’s own model showed that golimumab is not cost-effective compared with other biologics when the ICERs are correctly calculated. None of the sensitivity analyses carried out by the manufacturer or the ERG regarding uncertainty in the estimates of clinical effectiveness, the acquisition and administration cost of drugs, the cost of treating psoriasis and the utility functions estimated to generate health outcomes changed this conclusion. However, a key area in determining the cost-effectiveness of anti-TNF agents is whether they should be treated as a class. If all anti-TNF agents are considered equally effective then etanercept, adalimumab and golimumab have very nearly equal costs and equal quality-adjusted life-years (QALYs), and all have an ICER of about £15,000 per QALY versus palliative care, whereas infliximab with a higher acquisition cost is dominated by the other biologics.

Bevacizumab in combination with a taxane for the first-line treatment of HER2-negative metastatic breast cancer

This paper presents a summary of the evidence review group (ERG) report into the use of bevacizumab (Avastin®, Roche) in combination with a taxane for the treatment of untreated metastatic breast cancer (mBC). The main clinical effectiveness data were derived from a single, open-label randomised controlled trial (RCT) (E2100) that evaluated the addition of bevacizumab to weekly (q.w.) paclitaxel in patients with human epidermal growth factor receptor 2-negative mBC who had not previously received chemotherapy for advanced disease. This trial reported statistically significant increases in median progression-free survival (PFS) for the addition of bevacizumab (5.8–11.3 months). Median overall survival was not significantly different between the two groups; whether this is a true null finding or due to crossover between treatment arms cannot be established, as relevant data were not collected. The manufacturer reported that the addition of bevacizumab to paclitaxel q.w. therapy was associated with a significant improvement in quality of life, as measured by FACT-B (functional assessment of cancer therapy for breast cancer) scores. However, the ERG noted that these results were based on extreme imputed values, the removal of which led to non-significant differences in quality of life. The manufacturer conducted an indirect comparison. However, owing to methodological limitations and concerns about the validity and exchangeability of the included trials, the ERG did not consider the findings to be reliable. One additional relevant RCT [AVADO (Avastin and Docetaxel); BO17708] evaluating the addition of bevacizumab to docetaxel was excluded from the manufacturer’s submission. This was summarised by the ERG. In terms of response rate and PFS, AVADO reported a markedly smaller benefit of adding bevacizumab to docetaxel than that reported for adding bevacizumab to q.w. paclitaxel in E2100. AVADO also reported no statistically significant effect of combination therapy versus docetaxel in terms of overall survival. The manufacturer developed a de novo economic model that considered patients with the same baseline characteristics as women in the E2100 trial. The model assessed BEV + PAC – bevacizumab 10 mg/kg every 2 weeks in combination with paclitaxel 90 mg/m2 weekly for 3 weeks followed by 1 week of rest; PAC q.w. – paclitaxel (monotherapy) 90 mg/m2 weekly for 3 weeks followed by 1 week of rest; DOC – docetaxel (monotherapy) 75 mg/m2 on day 1 every 21 days (considered current UK NHS clinical practice in the submission); and GEM + PAC – gemcitabine 1250 mg/m2 on days 1 and 8 plus paclitaxel 175 mg/m2 on day 1 every 21 days. Pairwise comparisons were made between BEV + PAC and PAC (using the E2100 trial), BEV + PAC and DOC, and BEV + PAC and GEM + PAC. Based on NHS list prices, the manufacturer’s model estimated incremental cost-effectiveness ratios (ICERs) for BEV + PAC of £117,803, £115,059 and £105,777 per QALY gained, relative to PAC, DOC and GEM + PAC regimens, respectively. If the NHS Purchasing and Supply Agency prices for PAC with a 10-g cap on the cost per patient of BEV were used instead, the ICERs for BEV + PAC were estimated at £77,314, £57,753 and £60,101 per QALY, respectively. The submission suggested that the regimen of BEV + DOC is not cost-effective because it is considered less effective and more costly than BEV + PAC. Analysis by the ERG suggested that alternative assumptions can increase the ICERs further and, based on current prices, no plausible changes to the model assumptions will bring the ICERs for BEV + PAC lower.

Short-term hyperglycaemia causes non-reversible changes in arterial gene expression in a fully 'switchable' in vivo mouse model of diabetes

AIMS/HYPOTHESIS

Irreversible arterial damage due to early effects of hypo- or hyperglycaemia could account for the limited success of glucose-lowering treatments in preventing cardiovascular disease (CVD) events. We hypothesised that even brief hypo- or hyperglycaemia could adversely affect arterial gene expression and that these changes, moreover, might not be fully reversible.

METHODS

By controlled activation of a 'switchable' c-Myc transgene in beta cells, adult pIns-c-MycER(TAM) mice were rendered transiently hypo- and then hyperglycaemic, after which they were allowed to recover for up to 3 months. Immediate and sequential changes in aortic global gene expression from normal glycaemia through hypo- and hyperglycaemia to recovery were assessed.

RESULTS

Gene expression was compared with that of normoglycaemic transgenic and tamoxifen-treated wild-type controls. Overall, expression of 95 genes was significantly affected by moderate hypoglycaemia (glucose down to 2.5 mmol/l), whereas over 769 genes were affected by hyperglycaemia. Genes and pathways activated included several involved in atherogenic processes, such as inflammation and arterial calcification. Although expression of many genes recovered to initial pre-exposure levels when hyperglycaemia was corrected (74.9%), in one in four genes this did not occur. Quantitative reverse transcriptase PCR and immunohistochemistry verified the gene expression patterns of key molecules, as shown by global gene arrays.

CONCLUSIONS/INTERPRETATION

Short-term exposure to hyperglycaemia can cause deleterious and persistent changes in arterial gene expression in vivo. Brief hypoglycaemia also adversely affects gene expression, although less substantially. Together, these results suggest that early correction of hyperglycaemia and avoidance of hypoglycaemia may both be necessary to avoid excess CVD risk in diabetes.

[Refractive surgery]

The surgical correction of refractive errors has gained widespread acceptance in the past 20 years, mainly through the introduction of the excimer laser. The excimer is used to ablate the cornea, renoving stromal tissue in the center (to correct myopia through flattening of the surface), or in the midperiphery (to steepen the cornea to correct hyperopia). Although excimer procedures dominate the field of refractive surgery, other approaches are also available. In the cornea itself, ring segments can be implanted, heat-induced coagulation effects can produce steepening, and cross-linking of the collagen fibers can stiffen a weakened structure. While all corneal procedures are extraocular, refractive surgery can also be performed within the eye. Special intraocular lenses can be implanted in the anterior chamber angle, fixated onto the iris, or placed in the posterior chamber in front of the crystalline lens. These so-called phakic intraocular lenses are available in different optical magnitudes and act to correct the patient's refractive error. Prebyopic individuals can have the crystalline lens removed in a procedure identical to cataract surgery. In such cases the lens is extracted even though no cataract is present, and an intraocular lens is implanted in the now empty capsular bag of the crystalline lens. The implanted lens serves to correct the preoperative refractive error.

Stapled haemorrhoidopexy for the treatment of haemorrhoids: a systematic review

OBJECTIVE

This systematic review aimed to evaluate the short- and long-term safety, efficacy and costs of stapled haemorrhoidopexy (SH) compared with conventional haemorrhoidectomy.

METHOD

We searched 26 electronic databases and websites for studies in any language up to July 2006. Inclusion criteria were predefined, and each stage of the review process was conducted in duplicate.

RESULTS

Twenty-seven randomized controlled trials were included (n = 2279). All had some methodological flaws. Postoperatively, 19 trials (95%) reported less pain, 17 (89%) reported a shorter operating time, 14 (88%) a shorter hospital stay, and 14 (93%) a shorter convalescence time following SH. However, prolapse was significantly more common after SH (OR 3.38; 95% CI: 1.00, 11.47). In the longer term, prolapse was significantly more common after SH (OR 4.34; 95% CI: 1.67, 11.28) as was reintervention for prolapse (OR 6.78; 95% CI: 2.00, 23.00). There were no differences in the rate or type of complications. Conventional haemorrhoidectomy and SH had similar costs during the initial admission.

CONCLUSION

Compared with conventional haemorrhoidectomy, SH resulted in less postoperative pain, shorter operating time, a shorter hospital stay, and a shorter convalescence, but a higher rate of prolapse and reintervention for prolapse.

Modelling the cost-effectiveness of first, second and third generation polychemotherapy regimens in women with early breast cancer who have differing prognoses

Abstract #6106

Purpose: To use individual patient data from three sequential large UK randomised trials to facilitate an integrated comparison of the cost-effectiveness of three generations of chemotherapy plus a no treatment option. The ABC trial compared CMF versus no chemo (1991 patients), NEAT trial Epirubicin-CMF versus CMF (2391 patients) and TACT FEC-Docetaxel vs FEC or epi-CMF (4162 patients)&#x2028; Methods: The model estimates lifetime costs and Quality-Adjusted Life Years (QALYs). Model inputs include transition probabilities which are estimated from a longitudinal observational study using parametric survival models incorporating characteristics such as number of positive lymph nodes, ER status, grade and tumour size that allow analyses to be conducted for women with differing baseline prognoses. The effects of each chemotherapy regimen on preventing recurrence are taken from the above UK trials and are assumed to be additive on the log scale to facilitate previously untested comparisons. Costs and utility decrements associated with chemotherapy, its toxicity, and type of recurrent disease, are informed from the trial data and published literature. A secondary analysis is performed by basing the effects of each chemotherapy regimen on published meta-analyses based on individual level data that include RCTs conducted in a range of multi-national settings.&#x2028; Results: For a woman aged 50 years with 1 positive node, grade 2 tumour size 2cm, ECMF is expected to be the most cost-effective regimen. However, the cost-effectiveness of the chemotherapy options varies between women with different risk factors. On the basis of the results of the TACT trial, 3rd generation chemotherapy is not cost-effective, but including evidence of the relative risk of recurrence from non-UK trials, particularly those with ER- and HER2+ phenotype, may alter this conclusion.&#x2028; Indicative lifetime costs and QALYs for a woman aged 50 years, with 1 positive node, grade 2 tumor size 2cm, with and without ER+ are shown:&#x2028; &#x2028; &#x2028; &#x2028; Conclusions: Evaluating the cost-effectiveness of chemotherapy regimens in women with early breast cancer who have differing prognoses is feasible using an integrative synthesis and model. Thought does, however, need to be given to how best present cost-effectiveness results when there are differing levels of baseline risk.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 6106.

The effectiveness and cost-effectiveness of minimal access surgery amongst people with gastro-oesophageal reflux disease - a UK collaborative study. The REFLUX trial

OBJECTIVES

To evaluate the clinical effectiveness, cost-effectiveness and safety of a policy of relatively early laparoscopic surgery compared with continued medical management amongst people with gastro-oesophageal reflux disease (GORD) judged suitable for both policies.

DESIGN

Relative clinical effectiveness was assessed by a randomised trial (with parallel non-randomised preference groups) comparing a laparoscopic surgery-based policy with a continued medical management policy. The economic evaluation compared the cost-effectiveness of the two management policies in order to identify the most efficient provision of future care and describe the resource impact that various policies for fundoplication would have on the NHS.

SETTING

A total of 21 hospitals throughout the UK with a local partnership between surgeon(s) and gastroenterologist(s) who shared the secondary care of patients with GORD.

PARTICIPANTS

The 810 participants, who were identified retrospectively or prospectively via their participating clinicians, had both documented evidence of GORD (endoscopy and/or manometry/24-hour pH monitoring) and symptoms for longer than 12 months. In addition, the recruiting clinician(s) was clinically uncertain about which management policy was best.

INTERVENTION

Of the 810 eligible patients who consented to participate, 357 were recruited to the randomised arm of the trial (178 allocated to surgical management, 179 allocated to continued, but optimised, medical management) and 453 recruited to the parallel non-randomised preference arm (261 chose surgical management, 192 chose to continue with best medical management). The type of fundoplication was left to the discretion of the surgeon.

MAIN OUTCOME MEASURES

Participants completed a baseline REFLUX questionnaire, developed specifically for this study, containing a disease-specific outcome measure, the Short Form with 36 Items (SF-36), the EuroQol-5 Dimensions (EQ-5D) and the Beliefs about Medicines and Surgery questionnaires (BMQ/BSQ). Postal questionnaires were completed at participant-specific time intervals after joining the trial (equivalent to approximately 3 and 12 months after surgery). Intraoperative data were recorded by the surgeons and all other in-hospital data were collected by the research nurse. At the end of the study period, participants completed a discrete choice experiment questionnaire.

RESULTS

The randomised groups were well balanced at entry. Participants had been taking GORD medication for a median of 32 months; the mean age of participants was 46 years and 66% were men. Of 178 randomised to surgery, 111 (62%) actually had fundoplication. There was a mixture of clinical and personal reasons why some patients did not have surgery, sometimes related to long waiting times. A total or partial wrap procedure was performed depending on surgeon preference. Complications were uncommon and there were no deaths associated with surgery. By the equivalent of 12 months after surgery, 38% in the randomised surgical group (14% amongst those who had surgery) were taking reflux medication compared with 90% in the randomised medical group. There were substantial differences (one-third to one-half standard deviation) favouring the randomised surgical group across the health status measures, the size depending on assumptions about the proportion that actually had fundoplication. These differences were the same or somewhat smaller than differences observed at 3 months. The lower the REFLUX score, the worse the symptoms at trial entry and the larger the benefit observed after surgery. The preference surgical group had the lowest REFLUX scores at baseline. These scores improved substantially after surgery, and by 12 months they were better than those in the preference medical group. The BMQ/BSQ and discrete choice experiment did distinguish the preference groups from each other and from the randomised groups. The latter indicated that the risk of serious complications was the most important single attribute of a treatment option. A within-trial cost-effectiveness analysis suggested that the surgery policy was more costly (mean 2049 pounds) but also more effective [+0.088 quality-adjusted life-years (QALYs)]. The estimated incremental cost per QALY was 19,000-23,000 pounds, with a probability between 46% (when 62% received surgery) and 19% (when all received surgery) of cost-effectiveness at a threshold of 20,000 pounds per QALY. Modelling plausible longer-term scenarios (such as lifetime benefit after surgery) indicated a greater likelihood (74%) of cost-effectiveness at a threshold of 20,000 pounds, but applying a range of alternative scenarios indicated wide uncertainty. The expected value of perfect information was greatest for longer-term quality of life and proportions of surgical patients requiring medication.

CONCLUSIONS

Amongst patients requiring long-term medication to control symptoms of GORD, surgical management significantly increases general and reflux-specific health-related quality of life measures, at least up to 12 months after surgery. Complications of surgery were rare. A surgical policy is, however, more costly than continued medical management. At a threshold of 20,000 pounds per QALY it may well be cost-effective, especially when putative longer-term benefits are taken into account, but this is uncertain. The more troublesome the symptoms, the greater the potential benefit from surgery. Uncertainty about cost-effectiveness would be greatly reduced by more reliable information about relative longer-term costs and benefits of surgical and medical policies. This could be through extended follow-up of the REFLUX trial cohorts or of other cohorts of fundoplication patients.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN15517081.

Stapled haemorrhoidectomy (haemorrhoidopexy) for the treatment of haemorrhoids: a systematic review and economic evaluation

OBJECTIVES

To determine the safety, clinical effectiveness and cost-effectiveness of circular stapled haemorrhoidopexy (SH) for the treatment of haemorrhoids.

DATA SOURCES

Main electronic databases were searched up to July 2006.

REVIEW METHODS

Randomised controlled trials (RCTs) with 20 or more participants that compared SH with any conventional haemorrhoidectomy (CH) technique in people of any age with prolapsing haemorrhoids for whom surgery is considered a relevant option, were used to evaluate clinical effectiveness. An economic model of the surgical treatment of haemorrhoids was developed.

RESULTS

The clinical effectiveness review included 27 RCTs (n = 2279; 1137 SH; 1142 CH). All had some methodological flaws; only two reported recruiting patients with second, third and fourth degree haemorrhoids, and 37% reported using an appropriate method of randomisation and/or allocation concealment. In the early postoperative period 95% of trials reported less pain following SH; by day 21 the pain reported following SH and CH was minimal, with little difference between the two techniques. Significantly fewer patients had unhealed wounds at 6 weeks following SH [odds ratio (OR) 0.08, 95% confidence interval (CI) 0.03 to 0.19, p < 0.001]. Residual prolapse was more common after SH (OR 3.38, 95% CI 1.00 to 11.47, p = 0.05, nine RCTs, results of a sensitivity analysis). There was no difference between SH and CH in the incidence of bleeding or postoperative complications. SH resulted in shorter operating times, hospital stay, time to first bowel movement and return to normal activity. In the short term (between 6 weeks and a year) prolapse was more common after SH (OR 4.68, 95% CI 1.11 to 19.71, p = 0.04, six RCTs). There was no difference in the number of patients complaining of pain between SH and CH. In the long term (1 year and over), there was a significantly higher rate of prolapse after SH (OR 4.34, 95% CI 1.67 to 11.28, p = 0.003, 12 RCTs). There was no difference in the number of patients experiencing pain, or the incidence of bleeding, between SH and CH. There was no difference in the total number of reinterventions, or reinterventions for pain, bleeding or complications, between SH and CH. Significantly more reinterventions were undertaken after SH for prolapse at 12 months or longer (OR 6.78, 95% CI 2.00 to 23.00, p = 0.002, six RCTs). Overall, there was no statistically significant difference in the rate of complications between SH and CH. In the economic assessment it was found that, on average, CH dominated SH. However, CH and SH had very similar costs and quality-adjusted life-years (QALYs). On average, the difference in costs between the procedures was 19 pounds and the difference in QALY was -0.001, favouring CH, over 3 years. In terms of QALYs, the superior quality of life due to lower pain levels in the early postoperative period with SH was offset by the higher rate of symptoms over the follow-up period, compared with CH. The results are very sensitive to modelling assumptions, particularly the valuation of utility in the early postoperative period. The probabilistic sensitivity analysis showed that, at a threshold incremental cost-effectiveness ratio of 20,000-30,000 pounds per QALY, SH had a 45% probability of being cost-effective.

CONCLUSIONS

SH was associated with less pain in the immediate postoperative period, but a higher rate of residual prolapse, prolapse in the longer term and reintervention for prolapse. There was no clear difference in the rate or type of complications associated with the two techniques and the absolute and relative rates of recurrence and reintervention for both are still uncertain. CH and SH had very similar costs and QALYs, the cost of the staple gun being offset by savings in hospital stay. Should the price of the gun change, the conclusions of the economic analysis may also change. Some training may be required in the use of the staple gun; this is not expected to have major resource implications. Given the currently available clinical evidence and the results of the economic analysis, the decision as to whether SH or CH is conducted could primarily be based on the priorities and preferences of the patient and surgeon. An adequately powered, good-quality RCT is required, comparing SH with CH, recruiting patients with second, third and fourth degree haemorrhoids, and having a minimum follow-up period of 5 years to ensure an adequate evaluation of the reintervention rate. Other areas for research are the effectiveness of SH in patients with fourth degree haemorrhoids and patients with co-morbid conditions, the reintervention rates for all treatments for haemorrhoids, utilities of patients up to 6 months postoperatively, the trade-offs of patients for short-term pain versus long-term outcomes, and the ability of SH to reduce hospital stays in a real practice setting.

[An economic assessment of genetic testing for familial adenomatous polyposis]

OBJECTIVE

To analyze the cost-effectiveness of genetic testing for first-degree relatives of patients with colon cancer to identify mutations in the APC gene (Adenomatous Polyposis Coli).

METHODOLOGY

Analyses were performed from the perspective of the health system. We used a Markov model. We compared genetic testing for the APC gene, the cause of familial adenomatous polyposis (FAP), which results in colon cancer, versus no genetic testing for said gene. The effectiveness measure used was quality-adjusted life-years (QALYs), and costs were measured in euros for 2005. The costs of interventions were extracted from the costs of health services provided by centers under the Andalusian Public Health System, and other parameters were obtained from the literature.

RESULTS

The performance of genetic testing is the dominant strategy when compared to the absence of genetic testing given the latter option has an incremental cost of 7,676.34 euros and is less effective. A sensitivity analysis found that genetic testing remains the dominant strategy for a plausible range of costs of the test itself, and for the probability of developing adenocarcinoma.

CONCLUSIONS

Our analysis showed that in this patient group genetic testing to detect APC gene mutations is on average less costly and improves QALYs versus no testing.

Distinct classes of pyramidal cells exhibit mutually exclusive firing patterns in hippocampal area CA3b

It is thought that CA3 pyramidal neurons communicate mainly through bursts of spikes rather than so-called trains of regular firing action potentials. Reports of both burst firing and nonburst firing CA3 cells suggest that they may fire with more than one output pattern. With the use of whole-cell recording methods we studied the firing properties of rat hippocampal pyramidal neurons in vitro within the CA3b subregion and found three distinct types of firing patterns. Approximately 37% of cells were regular firing where spikes generated by minimal current injection (rheobase) were elicited with a short latency and with stronger current intensities trains of spikes exhibited spike frequency adaptation (SFA). Another 46% of neurons exhibited a delayed onset at rheobase with a weakly-adapting firing pattern upon stronger stimulation. The remaining 17% of cells showed a burst-firing pattern, though only elicited in response to strong current injection and spontaneous bursts were never observed. Control experiments indicated that the distinct firing patterns were not due to our particular slicing methods or recording techniques. Finally, computer modeling was used to identify how relative differences in K+ conductances, specifically K(C), K(M), and K(D), between cells contribute to the different characteristics of the three types of firing patterns observed experimentally.

Corneal Topography-Guided Penetrating Keratoplasty and Suture Adjustment

PURPOSE

To describe a new keratoplasty procedure using intraoperative topography to reduce postoperative astigmatism.

METHODS

One hundred sixty-five eyes of 150 consecutive patients were enrolled in this prospective study. The most common diagnosis was keratoconus (78.8%). As many as 5.5% had post-laser in situ keratomileusis ectasia. Keratoplasty was performed with the Hanna Corneal Trephine System. A 24-bite running suture was placed, using a specially developed marker. Suture adjustment was performed with the aid of an intraoperative topographer (Keratron Scout; OPTIKON 2000, Rome, Italy). The aim of the adjustment was to obtain an astigmatism < or =2.0 D on the operating table. In case of >3.0 D of astigmatism at 1 month after surgery, suture adjustment was performed using the same intraoperative topographer.

RESULTS

At 12 months postoperatevely (suture in), data from 108 (64%) eyes were available. The mean refractive astigmatism was 3.53 D, and the mean topographical astigmatism was 4.7 D. At 18 months (suture out), data from 32 eyes (19.4%) were available, and at 24 months, data from 29 eyes (13.3%) were available. The mean refractive astigmatism was 3.39 D at 18 months and 3.47 D at 24 months. The mean topographic astigmatism was 2.30 D at 18 months and 1.76 D at 24 months. Mean best spectacle-corrected visual acuity (BSCVA) was 0.51 at 3 months, 0.63 at 12 months (suture in), 0.67 at 18 months (suture out), and 0.78 at 24 months postoperatively.

CONCLUSIONS

The combination of intraoperative topography and a 24-bite single running suture resulted in a stable astigmatism throughout the follow-up period, even after suture removal. BSCVA reached a 20/40 level as early as 3 months postoperatively and continued to rise after suture removal. The stability of astigmatism and BSCVA shortened the postoperative visual rehabilitation time and provided a high quality of vision early in the postoperative period.

Review article: the diagnosis and management of Crohn's disease in populations with high-risk rates for tuberculosis

BACKGROUND

Distinguishing Crohn's disease from intestinal tuberculosis in endemic areas is challenging as both conditions have overlapping clinical, radiological, endoscopic and histological characteristics. Furthermore, high rates of latent tuberculosis confer a considerable risk of reactivation once therapy for established Crohn's disease is started.

AIM

To review current strategies in differentiating these two conditions, and in managing Crohn's disease, in populations with high rates of tuberculosis.

METHODS

Literature review and clinical experience.

RESULTS

While various clinical, radiological, endoscopic and histological parameters may aid in differentiating Crohn's disease from intestinal tuberculosis, these remain imperfect and as treatment options differ misdiagnosis has grave consequences. We propose a diagnostic algorithm, based on currently available evidence and experience, to aid in this dilemma. We also discuss approaches to the management of Crohn's disease, including agents targeting tumour necrosis factor-alpha, in patients at risk of developing tuberculosis.

CONCLUSIONS

A diagnosis of Crohn's disease in individuals at risk for tuberculosis should only be made after careful interpretation of clinical signs, abdominal imaging and systematic endoscopic and histological assessment. Newer techniques for the diagnosis of latent tuberculosis still need to be validated in this environment, and guidelines on the treatment of latent tuberculosis in this setting require clarification.