The clinical effectiveness and cost-effectiveness of different surveillance mammography regimens after the treatment for primary breast cancer: systematic reviews registry database analyses and economic evaluation

BACKGROUND

Following primary breast cancer treatment, the early detection of ipsilateral breast tumour recurrence (IBTR) or ipsilateral secondary cancer in the treated breast and detection of new primary cancers in the contralateral breast is beneficial for survival. Surveillance mammography is used to detect these cancers, but the optimal frequency of surveillance and the length of follow-up are unclear.

OBJECTIVES

To identify feasible management strategies for surveillance and follow-up of women after treatment for primary breast cancer in a UK setting, and to determine the effectiveness and cost-effectiveness of differing regimens.

METHODS

A survey of UK breast surgeons and radiologists to identify current surveillance mammography regimens and inform feasible alternatives; two discrete systematic reviews of evidence published from 1990 to mid 2009 to determine (i) the clinical effectiveness and cost-effectiveness of differing surveillance mammography regimens for patient health outcomes and (ii) the test performance of surveillance mammography in the detection of IBTR and metachronous contralateral breast cancer (MCBC); statistical analysis of individual patient data (West Midlands Cancer Intelligence Unit Breast Cancer Registry and Edinburgh data sets); and economic modelling using the systematic reviews results, existing data sets, and focused searches for specific data analysis to determine the effectiveness and cost-utility of differing surveillance regimens.

RESULTS

The majority of survey respondents initiate surveillance mammography 12 months after breast-conserving surgery (BCS) (87%) or mastectomy (79%). Annual surveillance mammography was most commonly reported for women after BCS or after mastectomy (72% and 53%, respectively). Most (74%) discharge women from surveillance mammography, most frequently 10 years after surgery. The majority (82%) discharge from clinical follow-up, most frequently at 5 years. Combining initiation, frequency and duration of surveillance mammography resulted in 54 differing surveillance regimens for women after BCS and 56 for women following mastectomy. The eight studies included in the clinical effectiveness systematic review suggest surveillance mammography offers a survival benefit compared with a surveillance regimen that does not include surveillance mammography. Nine studies were included in the test performance systematic review. For routine IBTR detection, surveillance mammography sensitivity ranged from 64% to 67% and specificity ranged from 85% to 97%. For magnetic resonance imaging (MRI), sensitivity ranged from 86% to 100% and specificity was 93%. For non-routine IBTR detection, sensitivity and specificity for surveillance mammography ranged from 50% to 83% and from 57% to 75%, respectively, and for MRI from 93% to 100% and from 88% to 96%, respectively. For routine MCBC detection, one study reported sensitivity of 67% and specificity of 50% for both surveillance mammography and MRI, although this was a highly select population. Data set analysis showed that IBTR has an adverse effect on survival. Furthermore, women experiencing a second tumour measuring >20 mm in diameter were at a significantly greater risk of death than those with no recurrence or those whose tumour was <10 mm in diameter. In the base-case analysis, the strategy with the highest net benefit, and most likely to be considered cost-effective, was surveillance mammography alone, provided every 12 months at a societal willingness to pay for a quality-adjusted life-year of either £20,000 or £30,000. The incremental cost-effectiveness ratio for surveillance mammography alone every 12 months compared with no surveillance was £4727.

LIMITATIONS

Few studies met the review inclusion criteria and none of the studies was a randomised controlled trial. The limited and variable nature of the data available precluded any quantitative analysis. There was no useable evidence contained in the Breast Cancer Registry database to assess the effectiveness of surveillance mammography directly. The results of the economic model should be considered exploratory and interpreted with caution given the paucity of data available to inform the economic model.

CONCLUSIONS

Surveillance is likely to improve survival and patients should gain maximum benefit through optimal use of resources, with those women with a greater likelihood of developing IBTR or MCBC being offered more comprehensive and more frequent surveillance. Further evidence is required to make a robust and informed judgement on the effectiveness of surveillance mammography and follow-up. The utility of national data sets could be improved and there is a need for high-quality, direct head-to-head studies comparing the diagnostic accuracy of tests used in the surveillance population.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

The first 3 years of national bowel cancer screening at a single UK tertiary centre

AIM

St Mark's Bowel Cancer Screening Centre commenced screening in October 2006 as a contributor to the national programme. The first 35 months' experience is reported.

METHOD

Individuals with a positive faecal occult blood test (FOBT) were offered colonoscopy or alternatives if they had significant comorbidity. All screening data were collected prospectively.

RESULTS

Of the 98 815 FOBT kits issued, 42 523 were returned (43% uptake; 20.79% men). In total, 1339/1488 (90%) FOBT-positive participants attended the nurse clinic (57% men). Of these, 1057 had an index colonoscopy, 115 had a computed tomography colonoscopy (CTC) and eight had a flexible sigmoidoscopy. Five hundred and seventeen (44%) procedures were 'normal' (no polyps/cancers). Eighty (6%) individuals had colorectal cancer. The polyp detection rate in index procedures, including colonoscopy, CTC and flexible sigmoidoscopy, was 50%. The adenoma detection rate of all colonoscopies was 62.8%. The median polyp size was 5 (1-80) mm. In total, 1200 colonoscopies were performed by five accredited colonoscopists (96% completion rate). There were 13 (1%) adverse events with < 1 in 500 patients undergoing polypectomy requiring a transfusion. There was one 30-day postsurgical mortality, one perforation and no colonoscopy-related mortality. Almost all 39/40 (97%) patients in the BCS programme felt that the findings were adequately explained compared with 21/32 (64%) elective patients (P < 0.001) within the same unit.

CONCLUSIONS

At this bowel cancer screening single centre, colonoscopy completion rates were high (unadjusted caecal intubation rate of 96%) and complication rates were low. In contrast to other published data, the uptake and cancer-detection rates were lower.

Clinical effectiveness and cost-effectiveness of imatinib dose escalation for the treatment of unresectable and/or metastatic gastrointestinal stromal tumours that have progressed on treatment at a dose of 400 mg/day: a systematic review and economic evaluation

BACKGROUND

Imatinib dose escalation is advocated for gastrointestinal stromal tumour (GIST) treatment, but its effectiveness compared with sunitinib and best supportive care (BSC) after failure at the 400 mg/day dose is unknown.

OBJECTIVES

To assess the effectiveness and cost-effectiveness of imatinib at escalated doses of 600 or 800 mg/day for patients with unresectable and/or metastatic GISTs whose disease had progressed on 400 mg/day.

DATA SOURCES

Electronic databases, including MEDLlNE, MEDLINE In-Process, EMBASE, BIOSIS, Science Citation Index, Health Management Information Consortium and the Cochrane Controlled Trials Register, were searched until September 2009.

REVIEW METHODS

A systematic review of the literature was carried out according to standard methods. An economic model was constructed to assess the cost-effectiveness of seven alternative pathways for treating patients with unresectable and/or metastatic GISTs.

RESULTS

Five primary studies involving 669 people were included for clinical effectiveness; four reported imatinib and one reported sunitinib. The data were essentially observational as none of the studies was designed to specifically assess treatment of patients whose disease had progressed on 400 mg/day imatinib. For 600 mg/day imatinib, between 26% and 42% of patients showed either a partial response (PR) or stable disease (SD). Median time to progression was 1.7 months (range 0.7-24.9 months). For 800 mg/day imatinib, between 29% and 33% of patients showed either a PR or SD. Median overall survival (OS) was 19 months [95% confidence interval (CI) 13 to 23 months]. Progression-free survival ranged from 81 days to 5 months (95% CI 2 to 10 months). Median duration of response was 153 days (range 37-574 days). Treatment progression led to 88% discontinuations but between 16% and 31% of patients required a dose reduction, and 23% required a dose delay. There was a statistically significant increase in the severity of fatigue (p < 0.001) and anaemia (p = 0.015) following dose escalation. For sunitinib, median OS was 90 weeks (95% CI 73 to 106 weeks). For the cost-effectiveness review, only one full-text study and one abstract were identified, comparing imatinib at an escalated dose, sunitinib and BSC, although neither was based on a UK context. The definition of BSC was not consistent across the studies, and the pattern of resources (including drugs for treatment) and measures of effectiveness also varied. Within the model, BSC (assumed to include continuing medication to prevent tumour flare) was the least costly and least effective. It would be the care pathway most likely to be cost-effective when the cost per quality-adjusted life-year threshold was < £25,000. Imatinib at 600 mg/day was most likely to be cost-effective at a threshold between £25,000 and £45,000. Imatinib at 600 mg/day followed by further escalation followed by sunitinib was most likely to be cost-effective at a threshold > £45,000.

LIMITATIONS

The evidence base was sparse, data were non-randomised and potentially biased. The economic model results are surrounded by a considerable degree of uncertainty and open to biases of unknown magnitude and direction.

CONCLUSIONS

Around one-third of patients with unresectable and/or metastatic GIST, who fail on 400 mg/day of imatinib, may show response or SD with escalated doses. Between a threshold of £25,000 and £45,000, provision of an escalated dose of imatinib would be most likely to be cost-effective. However, these results should be interpreted with caution owing to the limited evidence available on outcomes following imatinib dose escalation or sunitinib for this group of patients.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Individualization of surgical management for early-stage colonic cancer

A significant number of patients each year undergo radical segmental colectomy for node-negative colonic cancer in the UK. They are likely to represent 50% of our colonic cancer population in the future due to the implementation of the National Bowel Cancer Screening Programme. Short-term morbidity rates of up to 40% are associated with the current surgical treatment and need serious consideration. In this article, we discuss a combination of two techniques that will allow minimally invasive treatment in an increasing number of patients with early colonic cancer.

Eltrombopag for the treatment of chronic idiopathic (immune) thrombocytopenic purpura (ITP)

This paper presents a summary of the evidence review group (ERG) report into the clinical effectiveness and cost-effectiveness of eltrombopag for the treatment of adults with chronic idiopathic (immune) thrombocytopenic purpura (ITP), based on a review of the manufacturer’s submission (MS) to the National Institute for Health and Clinical Excellence (NICE) as part of the single technology appraisal process. ITP is an autoimmune disorder by which antibodies are formed against platelets with annual incidence rates in the UK/USA ranging from 1.13 to 6.62 cases per 100,000 adults. Eltrombopag increases the production of platelets at a rate that outpaces their destruction by the immune system, and has a UK marketing authorisation both for the treatment of adult ITP in splenectomised patients who are refractory to other treatments and as a second-line treatment for adult non-splenectomised patients for whom surgery is contraindicated. Both splenectomised and non-splenectomised patient groups were considered in the analysis. Two economic models were presented, one for a watch-and-rescue treatment scenario and the second for the long-term treatment of patients with more severe ITP. The submission’s evidence was sourced from the relatively high-quality RAISE [RAndomized placebo-controlled Idiopathic thrombocytopenic purpura (ITP) Study with Eltrombopag] randomised controlled trial. The study indicated a statistically significant difference in favour of eltrombopag compared with placebo in the odds of achieving the primary outcome of a platelet count of between 50 and 400 × 109/l during the 6-month treatment period (odds ratio 8.2, 99% confidence interval 3.6 to 18.7). In the eltrombopag group, 50/83 (60%) non-splenectomised patients and 18/49 (37%) splenectomised patients achieved this outcome. Median duration of response for all patients was 10.9 weeks (splenectomised patients 6 weeks and non-splenectomised patients 13.4 weeks). Patients treated with eltrombopag required less rescue medication and had lower odds of bleeding events than placebo-treated subjects in both patient groups. In the watch-and-rescue economic model, the ERG found that substantial reductions in the cost of eltrombopag are needed for the incremental cost-effectiveness ratio (ICER) to fall below £30,000. Further analyses found that the ICER varied from £33,561 to £103,500 per quality-adjusted life-year (QALY) (splenectomised) and from £39,657 to £150,245 per QALY (non-splenectomised). Other than bleeding, no adverse events were modelled. In relation to the long-term treatment model, the ERG found that using non-randomised non-comparative data may result in biased estimates of unknown magnitude and direction. None of the treatment sequences resulted in an ICER approaching the recommended threshold of £30,000. The base-case results, using a 2-year time horizon and prescribing eltrombopag as second-line treatment post rituximab, were found to be favourable towards eltrombopag. In conclusion, based on the MS and additional ERG work, eltrombopag appears to be a safe treatment for ITP (although long-term follow-up studies are awaited) and has short-term efficacy. However, there is no robust evidence on long-term efficacy or cost-effectiveness of eltrombopag, and there is a lack of robust direct evidence on the effectiveness and cost-effectiveness of eltrombopag compared with other relevant comparators. NICE did not recommend eltrombopag for the treatment of chronic ITP within its marketing authorisation for splenectomised or non-splenectomised patients.

The "FLEX" procedure: a new technique for full-thickness laparo-endoscopic excision in the colon

BACKGROUND AND STUDY AIMS

Colonic lesions unsuitable for endoscopic resection and some early cancers that have been incompletely excised endoscopically, are generally treated by segmental colectomy, even though local excision might be adequate. The aim of this study was to develop a laparo-endoscopic procedure for full-thickness local excision of the colon.

METHODS

After detailed planning using story-boarding to discuss each step of the procedure, both nonsurvival and survival experiments were performed in seven 50-kg pigs. The technique used was as follows: a simulated colonic polyp was created by endoscopic ink injection; this was inverted using laparo-endoscopically placed BraceBars passing from the outside to the inside of the colon; after laparoscopic over-sewing of the inversion in two layers, endoscopic full-thickness excision was performed. Pigs were sacrificed immediately (n=3) or between 7 and 9 days after surgery (n=4).

RESULTS

The procedure was performed without operative perforation or hemorrhage in a median of 233 min (range 201-245 min), and achieved full-thickness excision in all procedures. Specimen diameter was a median of 2.5 cm (range 2-3 cm). All survival pigs convalesced without complication and, at autopsy, normal luminal diameter was confirmed without any peritoneal reaction, hernia or sepsis. Bursting pressures were a median of 245 mmHg (range 240-260 mmHg), with the site of bursting being in normal colon in all but one pig.

CONCLUSIONS

This is a novel technique that permits full-thickness laparo-endoscopic excision (FLEX) of a colonic lesion as an alternative to segmental colectomy.

Enteral access by double-balloon enteroscopy: an alternative method of direct percutaneous endoscopic jejunostomy placement

BACKGROUND

Although direct percutaneous endoscopic jejunal feeding tube placement is an increasingly accepted method of providing small-bowel access for long-term enteral nutrition, it is reliant on push enteroscopy and remains a technically challenging procedure with significant failure rates. Double-balloon enteroscopy, with its ability to provide controlled small-bowel intubation may facilitate direct percutaneous endoscopic jejunal tube placement.

AIMS AND METHODS

We report a prospective series of ten consecutive cases of double-balloon enteroscopy-assisted direct percutaneous endoscopic jejunal placement, accompanied by a step-by-step illustrated overview of the technique.

RESULTS

Direct percutaneous endoscopic jejunal tube placement by double-balloon enteroscopy was successful in nine of the ten attempted cases. In the first case, direct percutaneous endoscopic jejunal placement was abandoned due to inadequate transillumination; there were no procedure-related complications in any of our patients.

CONCLUSIONS

This first reported prospective case series of double-balloon enteroscopy-assisted direct percutaneous endoscopic jejunal placement shows a promisingly high success rate; larger comparative studies are required to clearly establish any advantages over the originally described push enteroscopy method.

Effect of gender, age and deprivation on key performance indicators in a FOBT-based colorectal screening programme

OBJECTIVES

To assess the effect of gender, age and deprivation on key performance indicators in a colorectal cancer screening programme.

SETTING

Between March 2000 and May 2006 a demonstration pilot of biennial guaiac faecal occult blood test (gFOBT) colorectal screening was carried out in North-East Scotland for all individuals aged 50-69 years.

METHODS

The relevant populations were subdivided, by gender, into four age groups and into five deprivation categories according to the Scottish Index of Multiple Deprivation (SIMD), and key performance indicators analysed within these groups.

RESULTS

In all rounds, uptake of the gFOBT increased with age (P < 0.001), decreased with increasing deprivation in both genders (P < 0.001), and was consistently higher in women than in men in all age and all SIMD groups. In addition, increasing deprivation was negatively associated with uptake of colonoscopy in men with a positive gFOBT (P < 0.001) although this effect was not observed in women. Positivity rates increased with age (P < 0.001) and increasing deprivation (P < 0.001) in both genders in all rounds, although they were higher in men than in women for all age and SIMD categories. Cancer detection rates increased with age (P < 0.001), were higher in men than in women in all age and SIMD categories, but were not consistently related to deprivation. In both genders, the positive predictive value (PPV) for cancer increased with age (P < 0.001) and decreased with increasing deprivation (P < 0.001) in all rounds and was consistently higher in men than in women in all age and SIMD categories.

CONCLUSIONS

In this population-based colorectal screening programme gender, age, and deprivation had marked effects on key performance indicators, and this has implications both for the evaluation of screening programmes and for strategies designed to reduce inequalities.

Effect of repeated invitations on uptake of colorectal cancer screening using faecal occult blood testing: analysis of prevalence and incidence screening

OBJECTIVE

To analyse the effects of prevalence and incidence screening on uptake and detection of cancer in an ongoing, dynamic programme for colorectal screening using faecal occult blood testing.

DESIGN

Analysis of prevalence and incidence screening.

SETTING

Three rounds of biennial colorectal screening using the guaiac faecal occult blood test in east and north east Scotland, March 2000 to May 2007.

PARTICIPANTS

Adults aged 50-69.

MAIN OUTCOME MEASURES

Uptake of screening, test positivity (percentage of those invited who returned a test that was positive and triggered an invitation for colonoscopy), positive predictive value, and stage of cancer.

RESULTS

Of 510 990 screening episodes in all three rounds, 248 998 (48.7%) were for prevalence, 163 483 (32.0%) were for first incidence, and 98 509 (19.3%) were for second incidence. Uptake of a first invitation for prevalence screening was 53% and for a second and third invitation was 15% and 12%. In the cohort invited for the first round, uptake of prevalence screening rose from 55% in the first round to 63% in the third. The uptake of first incidence screening on a first invitation was 54% and on a second invitation was 86% and on a first invitation for second incidence screening was 46%. The positivity rate in prevalence screening was 1.9% and the uptake of colonoscopy was 87%. The corresponding values for a first incidence screen were 1.7% and 90% and for a second incidence screen were 1.1% and 94.5%. The positive predictive value of a positive faecal occult blood test result for cancer was 11.0% for prevalence screening, 6.5% for the first incidence screen, and 7.5% for the second incidence screen. The corresponding values for the positive predictive value for adenoma were 35.5%, 29.4%, and 26.7%. The proportion of cancers at stage I dropped from 46.5% for prevalence screening to 41% for first incidence screening and 35% for second incidence screening.

CONCLUSIONS

Repeat invitations to those who do not take up the offer of screening increases the number of those who accept, for both prevalence screening and incidence screening. Although the positive predictive value for both cancer and adenomas fell between the prevalence screen and the first incidence screen, they did not fall between the first and second incidence screens. The deterioration in cancer stage from prevalence to incidence screening suggests that some cancers picked up at incidence screening may have been missed on prevalence screening, but the stage distribution is still favourable. These data vindicate the policies of continuing to offer screening to those who fail to participate and continuing to offer biennial screening to those who have accepted previous offers.

The bipolar disorder risk allele at CACNA1C also confers risk of recurrent major depression and of schizophrenia

Molecular genetic analysis offers opportunities to advance our understanding of the nosological relationship between psychiatric diagnostic categories in general, and the mood and psychotic disorders in particular. Strong evidence (P=7.0 × 10(-7)) of association at the polymorphism rs1006737 (within CACNA1C, the gene encoding the α-1C subunit of the L-type voltage-gated calcium channel) with the risk of bipolar disorder (BD) has recently been reported in a meta-analysis of three genome-wide association studies of BD, including our BD sample (N=1868) studied within the Wellcome Trust Case Control Consortium. Here, we have used our UK case samples of recurrent major depression (N=1196) and schizophrenia (N=479) and UK non-psychiatric comparison groups (N=15316) to examine the spectrum of phenotypic effect of the bipolar risk allele at rs1006737. We found that the risk allele conferred increased risk for schizophrenia (P=0.034) and recurrent major depression (P=0.013) with similar effect sizes to those previously observed in BD (allelic odds ratio ∼1.15). Our findings are evidence of some degree of overlap in the biological underpinnings of susceptibility to mental illness across the clinical spectrum of mood and psychotic disorders, and show that at least some loci can have a relatively general effect on susceptibility to diagnostic categories, as currently defined. Our findings will contribute to a better understanding of the pathogenesis of major psychiatric illness, and such knowledge should be useful in providing an etiological rationale for shaping psychiatric nosology, which is currently reliant entirely on descriptive clinical data.

Systematic review of the clinical effectiveness and cost-effectiveness of rapid point-of-care tests for the detection of genital chlamydia infection in women and men

OBJECTIVE

To assess whether or not the Chlamydia Rapid Test (CRT) could improve detection of genital chlamydia, and whether it is more effective than current practice using nucleic acid amplification tests (NAATs), in terms of the number of cases of chlamydia that are detected and treated and the proportion of partners identified and treated.

DATA SOURCES

Eleven electronic bibliographic databases (including MEDLINE and EMBASE) were searched until November 2008, as well as relevant websites.

REVIEW METHODS

Studies of sexually active adolescent and adult women and men suspected of having or being tested for genital chlamydia infection were considered. The tests considered were the CRT and other comparator point-of-care tests identified, using a NAAT as a reference standard. Summary sensitivity, specificity, positive and negative likelihood ratios, and diagnostic odds ratios for each model were reported as a median and a 95% confidence interval (CI). Effectiveness was measured in terms of the absolute numbers of true-positives, false-positives, false-negatives (and other positive cases missed) and true-negatives detected. Costs were considered from the health service's perspective. Incremental cost-effectiveness ratios were used to examine the relative cost-effectiveness, and values of the major parameters of the models were varied in a sensitivity analysis.

RESULTS

Thirteen studies enrolling 8817 participants were included in the analysis. In the pooled estimates for the CRT, sensitivity (95% CI) was 80% (73% to 85%) for vaginal swab specimens and 77% (59% to 89%) for first void urine (FVU) specimens. Specificity was 99% (99% to 100%) for vaginal swab specimens and 99% (98% to 99%) for FVU specimens. In the pooled estimates for a comparator point-of-care test (Clearview Chlamydia), sensitivity (95% CI) was 52% (39% to 65%) for vaginal, cervical and urethral swab specimens combined, and 64% (47% to 77%) for cervical specimens alone. Specificity was 97% (94% to 100%) for vaginal, cervical and urethral swab specimens combined, and 97% (88% to 99%) for cervical specimens alone. The results of the economic evaluation showed that for a hypothetical cohort of 1000 people, using the current practice of polymerase chain reaction testing would result in 12.63 people who were offered testing being correctly treated and having their sexual partners contacted, at a cost of 7070 pounds (for the whole cohort). For the CRT, the number being correctly treated would be 10.98, at a cost of 7180 pounds. For the Clearview Chlamydia test, the number correctly treated would be 7.14, at a cost of 7170 pounds. Both point-of-care tests were therefore more costly and less effective than current practice.

CONCLUSIONS

The limited evidence available suggests that NAATs are still the most accurate and cost-effective method for diagnosing chlamydia infection. There may be circumstances in which point-of-care tests could be provided in addition to existing NAAT services, but there is currently little evidence on point-of-care methods in such settings. Robust evidence of the diagnostic accuracy of point-of-care tests for different types of samples is also still required, as are studies evaluating clinical effectiveness outcomes for these tests in comparison with NAATs.

Systematic review of the clinical effectiveness and cost-effectiveness of photodynamic diagnosis and urine biomarkers (FISH, ImmunoCyt, NMP22) and cytology for the detection and follow-up of bladder cancer

OBJECTIVE

To assess the clinical effectiveness and cost-effectiveness of photodynamic diagnosis (PDD) compared with white light cystoscopy (WLC), and urine biomarkers [fluorescence in situ hybridisation (FISH), ImmunoCyt, NMP22] and cytology for the detection and follow-up of bladder cancer.

DATA SOURCES

Major electronic databases including MEDLINE, MEDLINE In-Process, EMBASE, BIOSIS, Science Citation Index, Health Management Information Consortium and the Cochrane Controlled Trials Register were searched until April 2008.

REVIEW METHODS

A systematic review of the literature was carried out according to standard methods. An economic model was constructed to assess the cost-effectiveness of alternative diagnostic and follow-up strategies for the diagnosis and management of patients with bladder cancer.

RESULTS

In total, 27 studies reported PDD test performance. In pooled estimates [95% confidence interval (CI)] for patient-level analysis, PDD had higher sensitivity than WLC [92% (80% to 100%) versus 71% (49% to 93%)] but lower specificity [57% (36% to 79%) versus 72% (47% to 96%)]. Similar results were found for biopsy-level analysis. The median sensitivities (range) of PDD and WLC for detecting lower risk, less aggressive tumours were similar for patient-level detection [92% (20% to 95%) versus 95% (8% to 100%)], but sensitivity was higher for PDD than for WLC for biopsy-level detection [96% (88% to 100%) versus 88% (74% to 100%)]. For more aggressive, higher-risk tumours the median sensitivity of PDD for both patient-level [89% (6% to 100%)] and biopsy-level [99% (54% to 100%)] detection was higher than those of WLC [56% (0% to 100%) and 67% (0% to 100%) respectively]. Four RCTs comparing PDD with WLC reported effectiveness outcomes. PDD use at transurethral resection of bladder tumour resulted in fewer residual tumours at check cystoscopy [relative risk, RR, 0.37 (95% CI 0.20 to 0.69)] and longer recurrence-free survival [RR 1.37 (95% CI 1.18 to 1.59)] compared with WLC. In 71 studies reporting the performance of biomarkers and cytology in detecting bladder cancer, sensitivity (95% CI) was highest for ImmunoCyt [84% (77% to 91%)] and lowest for cytology [44% (38% to 51%)], whereas specificity was highest for cytology [96% (94% to 98%)] and lowest for ImmunoCyt [75% (68% to 83%)]. In the cost-effectiveness analysis the most effective strategy in terms of true positive cases (44) and life-years (11.66) [flexible cystoscopy (CSC) and ImmunoCyt followed by PDD in initial diagnosis and CSC followed by WLC in follow-up] had an incremental cost per life-year of over 270,000 pounds. The least effective strategy [cytology followed by WLC in initial diagnosis (average cost over 20 years 1403 pounds, average life expectancy 11.59)] was most likely to be considered cost-effective when society's willingness to pay was less than 20,000 pounds per life-year. No strategy was cost-effective more than 50% of the time, but four of the eight strategies in the probabilistic sensitivity analysis (three involving a biomarker or PDD) were each associated with a 20% chance of being considered cost-effective. In sensitivity analyses the results were most sensitive to the pretest probability of disease (5% in the base case).

CONCLUSIONS

The advantages of PDD's higher sensitivity in detecting bladder cancer have to be weighed against the disadvantages of a higher false-positive rate. Taking into account the assumptions made in the model, strategies involving biomarkers and/or PDD provide additional benefits at a cost that society might be willing to pay. Strategies replacing WLC with PDD provide more life-years but it is unclear whether they are worth the extra cost.

Romiplostim for the treatment of chronic immune or idiopathic thrombocytopenic purpura: a single technology appraisal

This paper presents a summary of the evidence review group (ERG) report into the clinical and cost-effectiveness of romiplostim for the treatment of adults with chronic immune or idiopathic thrombocytopenic purpura (ITP) 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 relatively high-quality randomised controlled trials (RCTs). The ERG found no evidence that any important data were missed or that data extraction was inaccurate. In both RCTs more patients in the romiplostim than in the placebo group achieved a durable platelet response [non-splenectomised patients: romiplostim 25/41 (61%), placebo 1/21 (5%), odds ratio (OR) 24.45, 95% confidence interval (CI) 3.34 to 179.18; splenectomised patients: romiplostim 16/42 (38%), placebo 0/21 (0%), OR 8.5 (95% CI 1.15 to 372)] and an overall platelet response [non-splenectomised patients: romiplostim 36/41 (88%), placebo 3/21 (14%), OR 34.74, 95% CI 7.77 to 155.38; splenectomised patients: romiplostim 33/42 (79%), placebo 0/21 (0%), OR 16.6 (95% CI 2.37 to 706]. The difference in mean period with a platelet response was 13.9 weeks (95% CI 10.5 to 17.4) in favour of romiplostim in the RCT of non-splectomised patients and 12.1 weeks (95% CI 8.7 to 15.6) in favour of romiplostim in the RCT of splectomised patients. The manufacturer's economic model evaluated the cost-effectiveness of romiplostim compared with standard care. The ERG had concerns about the way the decision problem was addressed in the economic model and about the non-adjustment of findings for confounding factors. In non-splenectomised patients, using romiplostim as a first option treatment, the base-case incremental cost-effectiveness ratio (ICER) was 14,840 pounds per quality-adjusted life-year (QALY). In splenectomised patients the ICER was 14,655 pounds per QALY. Additional sensitivity analyses performed by the ERG identified two issues of importance: whether individuals entered the model on watch and rescue or on active therapy in the comparator arm (ICER 21,674 pounds per QALY for non-splenectomised patients, 29,771 pounds per QALY for splenectomised patients); whether it was assumed that any unused medicine would be wasted. Combining all of the separate sensitivity analyses, and assuming that watch and rescue was not the first-line treatment, increased the ICERs further (non-splenectomised 37,290 pounds per QALY; splenectomised 131,017 pounds per QALY). In conclusion, the manufacturer's submission and additional work conducted by the ERG suggest that romiplostim has short-term efficacy for the treatment of ITP, but there is no robust evidence on long-term effectiveness or cost-effectiveness of romiplostim compared with relevant comparators.

Threshold parameters for a model of epidemic spread among households and workplaces

The basic reproduction number R0 is one of the most important concepts in modern infectious disease epidemiology. However, for more realistic and more complex models than those assuming homogeneous mixing in the population, other threshold quantities can be defined that are sometimes more useful and easily derived in terms of model parameters. In this paper, we present a model for the spread of a permanently immunizing infection in a population socially structured into households and workplaces/schools, and we propose and discuss a new household-to-household reproduction number RH for it. We show how RH overcomes some of the limitations of a previously proposed threshold parameter, and we highlight its relationship with the effort required to control an epidemic when interventions are targeted at randomly selected households.

Romiplostim for the treatment of chronic immune or idiopathic thrombocytopenic purpura: a single technology appraisal

This paper presents a summary of the evidence review group (ERG) report into the clinical and cost-effectiveness of romiplostim for the treatment of adults with chronic immune or idiopathic thrombocytopenic purpura (ITP) 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 relatively high-quality randomised controlled trials (RCTs). The ERG found no evidence that any important data were missed or that data extraction was inaccurate. In both RCTs more patients in the romiplostim than in the placebo group achieved a durable platelet response [non-splenectomised patients: romiplostim 25/41 (61%), placebo 1/21 (5%), odds ratio (OR) 24.45, 95% confidence interval (CI) 3.34 to 179.18; splenectomised patients: romiplostim 16/42 (38%), placebo 0/21 (0%), OR 8.5 (95% CI 1.15 to 372)] and an overall platelet response [non-splenectomised patients: romiplostim 36/41 (88%), placebo 3/21 (14%), OR 34.74, 95% CI 7.77 to 155.38; splenectomised patients: romiplostim 33/42 (79%), placebo 0/21 (0%), OR 16.6 (95% CI 2.37 to 706]. The difference in mean period with a platelet response was 13.9 weeks (95% CI 10.5 to 17.4) in favour of romiplostim in the RCT of non-splectomised patients and 12.1 weeks (95% CI 8.7 to 15.6) in favour of romiplostim in the RCT of splectomised patients. The manufacturer’s economic model evaluated the cost-effectiveness of romiplostim compared with standard care. The ERG had concerns about the way the decision problem was addressed in the economic model and about the non-adjustment of findings for confounding factors. In non-splenectomised patients, using romiplostim as a first option treatment, the base-case incremental cost-effectiveness ratio (ICER) was £14,840 per quality-adjusted life-year (QALY). In splenectomised patients the ICER was £14,655 per QALY. Additional sensitivity analyses performed by the ERG identified two issues of importance: whether individuals entered the model on watch and rescue or on active therapy in the comparator arm (ICER £21,674 per QALY for non-splenectomised patients, £29,771 per QALY for splenectomised patients); whether it was assumed that any unused medicine would be wasted. Combining all of the separate sensitivity analyses, and assuming that watch and rescue was not the first-line treatment, increased the ICERs further (non-splenectomised £37,290 per QALY; splenectomised £131,017 per QALY). In conclusion, the manufacturer’s submission and additional work conducted by the ERG suggest that romiplostim has short-term efficacy for the treatment of ITP, but there is no robust evidence on long-term effectiveness or cost-effectiveness of romiplostim compared with relevant comparators.