Febuxostat for the treatment of hyperuricaemia in people with gout: a single technology appraisal

This paper presents a summary of the evidence review group (ERG) report into the clinical effectiveness and cost-effectiveness of febuxostat for the management of hyperuricaemia in patients with gout based upon a review of the manufacturer's submission to the National Institute for Health and Clinical Excellence (NICE) as part of the single technology appraisal (STA) process. The submission's evidence came from two randomised controlled trials comparing the efficacy and safety of febuxostat with allopurinol. The trials were of reasonable methodological quality and measured a clinically relevant range of outcomes. A pooled clinical efficacy analysis showed that a daily dose of 80 mg or 120 mg of febuxostat was significantly more effective than fixed-dose allopurinol (300/100 mg/day) at lowering serum uric acid (sUA) levels to therapeutic targets (< 6 mg/dl); however, a large percentage of febuxostat patients did not achieve the primary end point and the fixed-dose allopurinol regimen may have introduced bias. There were no differences between treatments in more clinically important outcomes such as gout flares and tophi resolution after 52 weeks of treatment. No subgroup analyses were conducted for patients with renal impairment, non-responders to allopurinol or patients with severe disease. Supplementary data from a 2-year open-label extension study were also provided, but were difficult to interpret and poorly reported. The incidence of adverse events was similar between treatments, although more febuxostat recipients discontinued treatment prematurely. A decision tree model was developed to determine the cost-effectiveness of febuxostat. The scope was limited to the comparison of continual febuxostat treatment with continual allopurinol treatment. Switching between treatments or withdrawing treatment in patients whose sUA levels had not decreased was not permitted. The model predicted a cost-effectiveness of 16,324 pounds [95% confidence interval (CI) 6281 pounds to 239,928 pounds] per quality-adjusted life-year (QALY) gained for febuxostat compared with allopurinol after 2 years of treatment. The incremental cost per QALY was below 20,000 pounds in 63% of the simulations undertaken. Changes in the time horizon did not materially affect the results. The ERG believes that the modelling structure employed was not appropriate to estimate the cost-effectiveness of febuxostat within a treatment algorithm. In addition, there were concerns about the methodology used for collecting data on key model inputs. Given these reservations the cost-effectiveness of febuxostat could not be determined. The guidance issued by NICE in August 2008 as a result of the STA states that febuxostat is recommended as an option for the management of chronic hyperuricaemia in gout only for people who are intolerant of allopurinol or for whom allopurinol is contraindicated.

Rivaroxaban for the prevention of venous thromboembolism: a single technology appraisal

This paper presents a summary of the evidence review group (ERG) report into the clinical effectiveness and cost-effectiveness of rivaroxaban for the prevention of venous thromboembolism (VTE) in adult patients undergoing elective hip or knee replacement surgery based upon a review of the manufacturer's submission to the National Institute for Health and Clinical Excellence (NICE) as part of the single technology appraisal (STA) process. The submission's evidence came from four randomised controlled trials (RCTs) comparing rivaroxaban with enoxaparin [RECORD (Regulation of Coagulation in Orthopedic surgery to pRevent Deep venous thrombosis and pulmonary embolism) 1-4] and three comparing dabigatran with enoxaparin [RE-NOVATE (the prevention of venous thromboembolism after total hip replacement trial), RE-MODEL (the prevention of venous thromboembolism after total knee replacement trial) and RE-MOBILIZE (the prevention of venous thromboembolism after total knee arthroplasty trial)]. The evidence from the four RECORD trials indicates that rivaroxaban had superior efficacy over enoxaparin after total hip replacement (THR) and total knee replacement (TKR). For the composite primary outcome of any deep vein thrombosis (DVT), non-fatal pulmonary embolism (PE) and death from all causes the relative risk reductions were 70-79% in THR and 31-49% in TKR. Rivaroxaban also had superior efficacy over enoxaparin for the secondary outcome major VTE. Rivaroxaban was not inferior to enoxaparin on the safety outcome of major bleeding. After the correction of some errors found by the ERG, the manufacturer's economic model represented a reasonable model of patients receiving prophylaxis for THR or TKR. In the base-case analyses rivaroxaban dominated both enoxaparin and dabigatran. The incremental costs saved and quality-adjusted life-years (QALYs) gained were small (below 200 pounds and 0.005, respectively, per person). Analyses were conducted sampling from the distributions observed from the RCTs. When all parameters were sampled rivaroxaban dominated enoxaparin in all scenarios except for two, in which enoxaparin produced more QALYs than rivaroxaban and had an incremental cost per QALY gained of 5000 pounds and 8000 pounds respectively. Rivaroxaban dominated dabigatran when RECORD 1 and RECORD 2, individually or pooled, were compared with RE-NOVATE and when all four rivaroxaban RCTs pooled were compared with all three dabigatran RCTs. Dabigatran dominated rivaroxaban comparing RECORD 4 with RE-MODEL and RE-MOBILIZE, and was more cost-effective than rivaroxaban comparing RECORD 3 (incremental cost per QALY gained of rivaroxaban compared with dabigatran of 123,000 pounds) or RECORD 3 and RECORD 4 pooled (incremental cost per QALY gained of dabigatran compared with rivaroxaban of 400 pounds) with RE-MODEL and RE-MOBILIZE. In conclusion, the evidence indicates that rivaroxaban is not inferior to enoxaparin in terms of the primary and secondary outcomes. The submission presents a reasonable estimation of the cost-effectiveness of rivaroxaban compared with enoxaparin and dabigatran, although the uncertainty in the decision has been underestimated. The results are particularly sensitive to any assumed difference in the number of fatal PEs, but the ERG does not believe there is sufficient evidence to support a difference between interventions. The NICE guidance issued as a result of the STA states that: riveroxaban, within its marketing authorisation, is recommended as an option for the prevention of venous thromboembolism in adults having elective THR or elective TKB.

High-rate synthetic aperture communications in shallow water

Time reversal communication exploits spatial diversity to achieve spatial and temporal focusing in complex ocean environments. Spatial diversity can be provided easily by a vertical array in a waveguide. Alternatively, spatial diversity can be obtained from a virtual horizontal array generated by two elements, a transmitter and a receiver, due to relative motion between them, referred to as a synthetic aperture. This paper presents coherent synthetic aperture communication results from at-sea experiments conducted in two different frequency bands: (1) 2-4 kHz and (2) 8-20 kHz. Case (1) employs binary-phase shift-keying modulation, while case (2) involves up to eight-phase shift keying modulation with a data rate of 30 kbits/s divided by the number of transmissions (diversity) to be accumulated. The receiver utilizes time reversal diversity combining followed by a single channel equalizer, with frequent channel updates to accommodate the time-varying channel due to coupling of space and time in the presence of motion. Two to five consecutive transmissions from a source moving at 4 kts over 3-6 km range in shallow water are combined successfully after Doppler compensation, confirming the feasibility of coherent synthetic aperture communications using time reversal.

Mode-locked picosecond pulse generation from an octave-spanning supercontinuum

We generate mode-locked picosecond pulses near 1110 nm by spectrally slicing and reamplifying an octave-spanning supercontinuum source pumped at 1550 nm. The 1110 nm pulses are near transform-limited, with 1.7 ps duration over their 1.2 nm bandwidth, and exhibit high interpulse coherence. Both the supercontinuum source and the pulse synthesis system are implemented completely in fiber. The versatile source construction suggests that pulse synthesis from sliced supercontinuum may be a useful technique across the 1000 - 2000 nm wavelength range.

Randomized controlled trial and cost-effectiveness analysis of silver-donating antimicrobial dressings for venous leg ulcers (VULCAN trial)

BACKGROUND

Antimicrobial silver dressings are used beneath graduated compression in the treatment of venous ulceration. There is little information on whether their use is effective. This was a prospective randomized trial and cost-effectiveness analysis of silver-donating versus non-silver low-adherence dressings in the treatment of venous leg ulcers.

METHODS

Patients were randomized between the two types of dressing. The primary outcome measure was complete ulcer healing at 12 weeks. Secondary outcomes included time to healing, quality of life and cost-effectiveness.

RESULTS

A total of 213 patients were recruited. There was no difference between the dressings in the proportion of ulcers healed at 12 weeks (59.6 per cent for silver and 56.7 per cent for control dressings). Mean utility scores for the EuroQol 5D and Short Form 6D were similar in both groups at 1, 3, 6 and 12 months. Compared with the control group the antimicrobial group had an incremental cost of pounds sterling 97.85 and an incremental quality-adjusted life year gain of 0.0002, giving an incremental cost-effectiveness ratio of pounds sterling 489 250 for the antimicrobial dressings.

CONCLUSION

No significant differences were found in either primary or secondary endpoints. There was no evidence to support the routine use of silver-donating dressings beneath compression for venous ulceration.

REGISTRATION NUMBER

ISRCTN 72485131 (http://www.controlled-trials.com).

Socioeconomic status and risk of car crash injury, independent of place of residence and driving exposure: results from the DRIVE Study

BACKGROUND

Previous studies that found increased crash risks for young drivers of low socioeconomic status (SES) have failed to adjust for factors such as driving exposure and rural residence. This aim of this study is to examine the independent effect of SES on crash risk, adjusting for such factors, and to examine the relationship between injury severity following a crash and SES.

METHODS

Information on risk factors for crash collected from 20,822 newly licenced drivers aged 17-24 years in New South Wales, Australia, as part of the DRIVE Study was prospectively linked to hospitalisation data. SES was classified as high, moderate or low based on the Australia 2001 Socio-Economic Index for Areas. Poisson regression was used to model risk of crash-related hospitalisation by SES, adjusting for confounders. Two measures of injury severity--urgency of treatment and length of hospital stay--were examined by SES.

RESULTS

Results of multivariable analysis showed that drivers from low SES areas had increased relative risk (RR 1.8, 95% CI 1.1 to 3.1) of crash-related hospitalisation compared to drivers from high SES areas. This increased risk remained when adjusting for confounders including driving exposure and rurality (RR 1.9, 95% CI 1.1 to 3.2). No significant association was found between injury severity and SES.

CONCLUSION

The higher risk of crash-related hospitalisation for young drivers from low SES areas is independent of driving exposure and rural-urban differences. This finding may help improve and better target interventions for youth of low SES.

Febuxostat for the treatment of hyperuricaemia in people with gout: a single technology appraisal

This paper presents a summary of the evidence review group (ERG) report into the clinical effectiveness and cost-effectiveness of febuxostat for the management of hyperuricaemia in patients with gout based upon a review of the manufacturer’s submission to the National Institute for Health and Clinical Excellence (NICE) as part of the single technology appraisal (STA) process. The submission’s evidence came from two randomised controlled trials comparing the efficacy and safety of febuxostat with allopurinol. The trials were of reasonable methodological quality and measured a clinically relevant range of outcomes. A pooled clinical efficacy analysis showed that a daily dose of 80 mg or 120 mg of febuxostat was significantly more effective than fixed-dose allopurinol (300/100 mg/day) at lowering serum uric acid (sUA) levels to therapeutic targets (< 6 mg/dl); however, a large percentage of febuxostat patients did not achieve the primary end point and the fixed-dose allopurinol regimen may have introduced bias. There were no differences between treatments in more clinically important outcomes such as gout flares and tophi resolution after 52 weeks of treatment. No subgroup analyses were conducted for patients with renal impairment, non-responders to allopurinol or patients with severe disease. Supplementary data from a 2-year open-label extension study were also provided, but were difficult to interpret and poorly reported. The incidence of adverse events was similar between treatments, although more febuxostat recipients discontinued treatment prematurely. A decision tree model was developed to determine the cost-effectiveness of febuxostat. The scope was limited to the comparison of continual febuxostat treatment with continual allopurinol treatment. Switching between treatments or withdrawing treatment in patients whose sUA levels had not decreased was not permitted. The model predicted a cost-effectiveness of £16,324 [95% confidence interval (CI) £6281 to £239,928] per quality-adjusted life-year (QALY) gained for febuxostat compared with allopurinol after 2 years of treatment. The incremental cost per QALY was below £20,000 in 63% of the simulations undertaken. Changes in the time horizon did not materially affect the results. The ERG believes that the modelling structure employed was not appropriate to estimate the cost-effectiveness of febuxostat within a treatment algorithm. In addition, there were concerns about the methodology used for collecting data on key model inputs. Given these reservations the cost-effectiveness of febuxostat could not be determined. The guidance issued by NICE in August 2008 as a result of the STA states that febuxostat is recommended as an option for the management of chronic hyperuricaemia in gout only for people who are intolerant of allopurinol or for whom allopurinol is contraindicated.

Rivaroxaban for the prevention of venous thromboembolism: a single technology appraisal

This paper presents a summary of the evidence review group (ERG) report into the clinical effectiveness and cost-effectiveness of rivaroxaban for the prevention of venous thromboembolism (VTE) in adult patients undergoing elective hip or knee replacement surgery based upon a review of the manufacturer’s submission to the National Institute for Health and Clinical Excellence (NICE) as part of the single technology appraisal (STA) process. The submission’s evidence came from four randomised controlled trials (RCTs) comparing rivaroxaban with enoxaparin [RECORD (Regulation of Coagulation in Orthopedic surgery to pRevent Deep venous thrombosis and pulmonary embolism) 1–4] and three comparing dabigatran with enoxaparin [RE-NOVATE (the prevention of venous thromboembolism after total hip replacement trial), RE-MODEL (the prevention of venous thromboembolism after total knee replacement trial) and RE-MOBILIZE (the prevention of venous thromboembolism after total knee arthroplasty trial)]. The evidence from the four RECORD trials indicates that rivaroxaban had superior efficacy over enoxaparin after total hip replacement (THR) and total knee replacement (TKR). For the composite primary outcome of any deep vein thrombosis (DVT), non-fatal pulmonary embolism (PE) and death from all causes the relative risk reductions were 70–79% in THR and 31–49% in TKR. Rivaroxaban also had superior efficacy over enoxaparin for the secondary outcome major VTE. Rivaroxaban was not inferior to enoxaparin on the safety outcome of major bleeding. After the correction of some errors found by the ERG, the manufacturer’s economic model represented a reasonable model of patients receiving prophylaxis for THR or TKR. In the base-case analyses rivaroxaban dominated both enoxaparin and dabigatran. The incremental costs saved and quality-adjusted life-years (QALYs) gained were small (below £200 and 0.005, respectively, per person). Analyses were conducted sampling from the distributions observed from the RCTs. When all parameters were sampled rivaroxaban dominated enoxaparin in all scenarios except for two, in which enoxaparin produced more QALYs than rivaroxaban and had an incremental cost per QALY gained of £5000 and £8000 respectively. Rivaroxaban dominated dabigatran when RECORD 1 and RECORD 2, individually or pooled, were compared with RE-NOVATE and when all four rivaroxaban RCTs pooled were compared with all three dabigatran RCTs. Dabigatran dominated rivaroxaban comparing RECORD 4 with RE-MODEL and RE-MOBILIZE, and was more cost-effective than rivaroxaban comparing RECORD 3 (incremental cost per QALY gained of rivaroxaban compared with dabigatran of £123,000) or RECORD 3 and RECORD 4 pooled (incremental cost per QALY gained of dabigatran compared with rivaroxaban of £400) with RE-MODEL and RE-MOBILIZE. In conclusion, the evidence indicates that rivaroxaban is not inferior to enoxaparin in terms of the primary and secondary outcomes. The submission presents a reasonable estimation of the cost-effectiveness of rivaroxaban compared with enoxaparin and dabigatran, although the uncertainty in the decision has been underestimated. The results are particularly sensitive to any assumed difference in the number of fatal PEs, but the ERG does not believe there is sufficient evidence to support a difference between interventions. The NICE guidance issued as a result of the STA states that: riveroxaban, within its marketing authorisation, is recommended as an option for the prevention of venous thromboembolism in adults having elective THR or elective TKB.

High-frequency acoustic communications achieving high bandwidth efficiency

A recent communications experiment was conducted in a shallow water environment at high-frequency permitting the use of a large bandwidth (11-19 kHz). This paper investigates the communication performance versus various symbol rates (or bandwidths) in terms of output signal-to-noise ratio with an assortment of constellations, illustrating a trade-off between performance and data rate. A high bandwidth efficiency of 4 bits/s Hz is demonstrated using 32 quadrature amplitude modulation with a data rate of 31.25 kbits/s over a 2.2-km range.

A study of the physical rehabilitation and psychological state of patients who sustained limb loss as a result of terrorist activity in Northern Ireland 1969 – 2003

OBJECTIVE

To benchmark the psychological state and physical rehabilitation of patients who have sustained limb loss as a result of terrorist activity in Northern Ireland and to determine their satisfaction with the period of primary prosthetic rehabilitation and the artificial limb.

METHOD

All patients who sustained limb loss as a result of the Troubles and were referred to our rehabilitation centre were sent a questionnaire. The main outcome measures were the SIGAM mobility grades, the General Health Questionnaire (GHQ12) and three screening questions for Post Traumatic Stress Disorder (PTSD).

RESULTS

Out of a 66% response rate, 52 (69%) patients felt that the period of primary prosthetic rehabilitation was adequate; 32 (54%) lower limb amputees graded themselves SIGAM C or D; 45 (60%) patients stated that they were still having significant stump pain. Significant stump pain was associated with poorer mobility. Nine (56%) upper limb amputees used their prosthetic limb in a functional way; 33 (44%) patients showed "psychiatric caseness" on the GHQ 12 and 50 (67%) had symptoms of PTSD.

CONCLUSIONS

Most patients felt that the period of physical rehabilitation had been adequate; those who did not were more likely to be having ongoing psychological problems. A high percentage of patients continue to have psychological problems and stump pain.

The effect of superstition on the day of discharge from maternity units in Northern Ireland: "A Saturday flit is a short sit"

The impetus for evidence-based practice arose from the science of maternity and childcare. Yet this has to coexist with patient preferences which are often based on a belief system far removed from science. This paper shows how a superstition, which suggests that moving on a Saturday is unlucky, affects a large proportion of discharges from maternity units in Northern Ireland. This is a descriptive study of the 77 018 patients admitted to maternity units in Northern Ireland between 1994/95 and 1996/97. Overall 3819 (35.7%) fewer patients than expected were discharged on Saturday and 2445 (23.2%) and 1834 (17.4%) more than expected were discharged on Friday and Sunday respectively. This means that at least 8097 patients were probably affected by the superstition. In an evidence-based world patient preferences are still evident.

Risk and type of crash among young drivers by rurality of residence: findings from the DRIVE Study

BACKGROUND

Most previous literature on urban/rural differences in road crashes has a primary focus on severe injuries or deaths, which may be largely explained by variations of medical resources. Little has been reported on police-reported crashes by geographical location, or crash type and severity, especially among young drivers.

METHODS

DRIVE is a prospective cohort study of 20,822 drivers aged 17-24 in NSW, Australia. Information on risk factors was collected via online questionnaire and subsequently linked to police-reported crashes. Poisson regression was used to analyse risk of various crash types by three levels of rurality of residence: urban, regional (country towns and surrounds) and rural.

RESULTS

Compared to urban drivers, risk of crash decreased with increasing rurality (regional adjusted RR: 0.7, 95% CI 0.6-0.9; rural adjusted RR: 0.5, 95% CI 0.3-0.7). Among those who crashed, risk of injurious crash did not differ by geographic location; however, regional and rural drivers had significantly higher risk of a single versus multiple vehicle crash (regional adjusted RR 1.8, 95% CI 1.3-2.5; rural adjusted RR: 2.0, 95% CI 1.1-3.6), which was explained by speeding involvement and road alignment at the time or site of crash.

CONCLUSIONS

Although young urban drivers have a higher crash risk overall, rural and regional residents have increased risk of a single vehicle crash. Interventions to reduce single vehicle crashes should aim to address key issues affecting such crashes, including speeding and specific aspects of road geometry.

Association between human cases and poultry outbreaks of highly pathogenic avian influenza in Vietnam from 2003 to 2007: a nationwide study

This study quantifies the spatio-temporal association between outbreaks of highly pathogenic avian influenza H5N1 in domestic poultry (n = 3050) and human cases (n = 99) in Vietnam during 2003-2007, using rare events logistic regression. After adjusting for the effect of known confounders, the odds of a human case being reported to authorities increased by a factor of 6.17 [95% confidence interval (CI) 3.33-11.38] and 2.48 (95% CI 1.20 - 5.13) if poultry outbreaks were reported in the same district 1 week and 4 weeks later respectively. When jointly considering poultry outbreaks in the same and neighbouring districts, occurrence of poultry outbreaks in the same week, 1-week later, and 4 weeks later increased the odds of a human case by a factor of 2.75 (95% CI 1.43-5.30), 2.56 (95% CI 1.31-5.00) and 2.70 (95% CI 1.56-4.66) respectively. Our study found evidence of different levels of association between human cases and poultry outbreaks in the North and the South of the country. When considering the 9-week interval extending from 4 weeks before to 4 weeks after the week of reporting a human case, in the South poultry outbreaks were recorded in 58% of cases in the same district and 83% of cases in either the same or neighbouring districts, whereas in the North the equivalent results were only 23% and 42%. The strength of the association between human and poultry cases declined over the study period. We conclude that owner reporting of clinical disease in poultry needs to be enhanced by targeted agent-specific surveillance integrated with preventive and other measures, if human exposure is to be minimized.

Chewing as a social act: cultural displacement and khat consumption in the East African communities of Melbourne

In this paper we present a review of practices surrounding the consumption of khat (Catha edulis) within recent migrant communities in Melbourne from East Africa. Cultures in East Africa and the Arabian Peninsular have used khat as a stimulant since the seventh century and the practice of coming together to chew the leaves of the khat plant has acquired unique cultural importance. Based on focus-group interviews the research examines transformations taking place in the meaning of khat for East African communities within their experiences of displacement and considers how the arrival of khat might be managed in the Australian context. Emphasis is given to indigenous models and the cultural context of practices surrounding khat. This anthropology of khat use in Melbourne summarizes issues such as who chews it, traditional settings for khat gatherings, culturally defined effects of the leaf, health effects, beliefs and attitudes, levels of use, gendered attitudes and questions of dependence. These issues raise questions regarding the reception of indigenous substance use within a state that claims to be multicultural.