Use of pharmacodynamic modeling for Bayesian information borrowing in pediatric clinical trials.

The use of Bayesian methodology to design and analyze pediatric efficacy trials is one of the possible options to reduce their sample size. This reduction of the sample size results from the use of an informative prior for the parameters of interest. In most of the applications, the principle of 'information borrowing' from adults' trials is applied, which means that the informative prior is constructed using efficacy results in adult of the drug under investigation. This implicitly assumes similarity in efficacy between the selected pediatric dose and the efficacious dose in adults. The goal of this article is to propose a method to construct prior distribution for the parameter of interest, not directly constructed from the efficacy results of the efficacious dose in adult patients but using pharmacodynamic modeling of a bridging biomarker using early phase pediatric data. When combined with a model bridging the biomarker with the clinical endpoints, the prior is constructed using a variational method after simulation of the parameters of interest. A use case application illustrates how the method can be used to construct a realistic informative prior.

Selective effects of focusing on spatial details in episodic future thinking for self-relevant positive events.

Mental simulations of positive future events increase their detail/vividness and plausibility, with effects on cognitive-affective processes such as anticipated and anticipatory pleasure. More recently, spatial details have been distinguished as important in increasing detail and elaborating mental scene construction. Building on this research, this study (N = 54; M age = 26.9) compared simulations of positive, self-relevant future events spatial details (i.e. people, objects, sequences of actions) with simulations focused on content details. Cross-sectionally at baseline, spatial details uniquely predicted phenomenological characteristics of future events, including anticipatory pleasure. The guided simulations increased detail and vividness, mental imagery, and pre-experiencing in both conditions. The content simulation condition did not increase content details relative to the spatial simulation condition, however, the inverse was true. Relatedly, overall detail and vividness were higher in the spatial condition, as was perceived control. The findings are discussed in relation to future thinking and mental health.

Concentration-QT modelling shows no evidence of clinically significant QT interval prolongation with capivasertib at expected therapeutic concentrations.

Pharmacokinetics-matched digital electrocardiogram data (n = 503 measurements from 180 patients) collected in a first-in-human, multi-part, dose-escalation (from 80 to 800 mg) and dose expansion (at 480 mg) phase 1 study in patients with advanced solid malignancies, were used to assess potential risk of QT prolongation associated with the AKT inhibitor capivasertib. The relationship between plasma drug concentrations and baseline-adjusted Fridericia-corrected QT (ΔQTcF) values was estimated using a prespecified linear mixed-effects model. The model provided an unbiased reproduction of the experimental data set, estimating a small but positive correlation between capivasertib concentration and ΔQTcF. At the expected therapeutic dose (400 mg twice daily) the predicted mean ΔQTcF at the steady state maximum concentration was 3.97 ms with an upper limit of the 90% CI of 5.07 ms; below the 10 ms limit proposed by ICH E14 guidance. This analysis suggests that capivasertib is not expected to present a clinically significant risk for QT prolongation that is associated with pro-arrhythmic effects.

An economic evaluation of the randomized controlled trial of topical corticosteroid and home-based narrowband ultraviolet B for active and limited vitiligo (the HI-Light Vitiligo Trial).

BACKGROUND: Economic evidence for vitiligo treatments is absent. OBJECTIVES: To determine the cost-effectiveness of (i) handheld narrowband ultraviolet B (NB-UVB) and (ii) a combination of topical corticosteroid (TCS) and NB-UVB compared with TCS alone for localized vitiligo. METHODS: Cost-effectiveness analysis alongside a pragmatic, three-arm, placebo-controlled randomized controlled trial with 9 months' treatment. In total 517 adults and children (aged ≥ 5 years) with active vitiligo affecting < 10% of skin were recruited from secondary care and the community and were randomized 1: 1: 1 to receive TCS, NB-UVB or both. Cost per successful treatment (measured on the Vitiligo Noticeability Scale) was estimated. Secondary cost-utility analyses measured quality-adjusted life-years using the EuroQol 5 Dimensions 5 Levels for those aged ≥ 11 years and the Child Health Utility 9D for those aged 5 to < 18 years. The trial was registered with number ISRCTN17160087 on 8 January 2015. RESULTS: The mean ± SD cost per participant was £775 ± 83·7 for NB-UVB, £813 ± 111.4 for combination treatment and £600 ± 96·2 for TCS. In analyses adjusted for age and target patch location, the incremental difference in cost for combination treatment compared with TCS was £211 (95% confidence interval 188-235), corresponding to a risk difference of 10·9% (number needed to treat = 9). The incremental cost was £1932 per successful treatment. The incremental difference in cost for NB-UVB compared with TCS was £173 (95% confidence interval 151-196), with a risk difference of 5·2% (number needed to treat = 19). The incremental cost was £3336 per successful treatment. CONCLUSIONS: Combination treatment, compared with TCS alone, has a lower incremental cost per additional successful treatment than NB-UVB only. Combination treatment would be considered cost-effective if decision makers are willing to pay £1932 per additional treatment success.

Randomized controlled trial of topical corticosteroid and home-based narrowband ultraviolet B for active and limited vitiligo: results of the HI-Light Vitiligo Trial.

BACKGROUND: Evidence for the effectiveness of vitiligo treatments is limited. OBJECTIVES: To determine the effectiveness of (i) handheld narrowband UVB (NB-UVB) and (ii) a combination of potent topical corticosteroid (TCS) and NB-UVB, compared with TCS alone, for localized vitiligo. METHODS: A pragmatic, three-arm, placebo-controlled randomized controlled trial (9-month treatment, 12-month follow-up). Adults and children, recruited from secondary care and the community, aged ≥ 5 years and with active vitiligo affecting < 10% of skin, were randomized 1 : 1 : 1 to receive TCS (mometasone furoate 0·1% ointment + dummy NB-UVB), NB-UVB (NB-UVB + placebo TCS) or a combination (TCS + NB-UVB). TCS was applied once daily on alternating weeks; NB-UVB was administered on alternate days in escalating doses, adjusted for erythema. The primary outcome was treatment success at 9 months at a target patch assessed using the participant-reported Vitiligo Noticeability Scale, with multiple imputation for missing data. The trial was registered with number ISRCTN17160087 on 8 January 2015. RESULTS: In total 517 participants were randomized to TCS (n = 173), NB-UVB (n = 169) and combination (n = 175). Primary outcome data were available for 370 (72%) participants. The proportions with target patch treatment success were 17% (TCS), 22% (NB-UVB) and 27% (combination). Combination treatment was superior to TCS: adjusted between-group difference 10·9% (95% confidence interval 1·0%-20·9%; P = 0·032; number needed to treat = 10). NB-UVB alone was not superior to TCS: adjusted between-group difference 5·2% (95% CI - 4·4% to 14·9%; P = 0·29; number needed to treat = 19). Participants using interventions with ≥ 75% expected adherence were more likely to achieve treatment success, but the effects were lost once treatment stopped. Localized grade 3 or 4 erythema was reported in 62 (12%) participants (including three with dummy light). Skin thinning was reported in 13 (2·5%) participants (including one with placebo ointment). CONCLUSIONS: Combination treatment with home-based handheld NB-UVB plus TCS is likely to be superior to TCS alone for treatment of localized vitiligo. Combination treatment was relatively safe and well tolerated but was successful in only around one-quarter of participants.

The impact of vacuum-assisted excision in the management of indeterminate B3 lesions in the NHS Breast Screening Programme in England.

AIM: To assess the impact of vacuum-assisted excision (VAE) on the management of B3 lesions in the England NHS Breast Screening Programme following an update of national guidance. A secondary aim was to investigate the histological features of malignancies resulting from upgrade of B3 lesions by either VAE or surgery. MATERIALS AND METHODS: The study population was all women recalled for assessment after breast screening who had a wide-bore needle biopsy with a B3 result over the period 01/04/2018 to 31/03/2019. Data were extracted from the National Breast Screening Service (NBSS) computer system at unit level. Women with a B3 result were split into those with and without atypia. The upgrade rates and histological features of malignancies in the different groups were analysed. RESULTS: In total, 2,234,514 women attended for screening between 1/4/218 and 31/3/2019, 84,559 women were referred to assessment, and of those 40,037 women had a core biopsy resulting in 3,355 were B3 lesions (8.38%). Within these, 556 cancers were diagnosed, giving an upgrade rate of 16.57% (556/3,355). The upgrade for B3 lesions with atypia was significantly higher than for B3 lesions without atypia (29.1% versus 13.3%, p<0.001). CONCLUSION: The introduction of the new B3 guidelines has resulted in 73.8% of B3 lesions with atypia and 65.1% of B3 lesions with no atypia having VAE rather than surgery. The data highlights the importance of managing these indeterminate lesions appropriately with an overall upgrade rate of 16.57%.

British Association of Dermatologists National Clinical Audit on the Management of Hidradenitis Suppurativa in the UK.

BACKGROUND: The first UK guidelines for the management of hidradenitis suppurativa (HS) were published by the British Association of Dermatologists (BAD) in 2018. The guidelines contained a set of audit criteria. AIM: To evaluate current HS management against the audit standards in the BAD guidelines. METHODS: BAD members were invited to complete audit questionnaires between January and May 2020 for five consecutive patients with HS per department. RESULTS: In total, 88 centres participated, providing data for 406 patients. Disease staging using the Hurley system and disease severity using a validated tool during follow-ups was documented in 75% and 56% of cases, respectively, while quality of life and pain were documented in 49% and 50% of cases, respectively. Screening for cardiovascular disease risk factors was as follows: smoking 75%, body mass index 27% and others such as lipids and diabetes 57%. Screening for depression and anxiety was performed in 40% and 25% of cases, respectively. Support for smokers or obese patients was documented in 35% and 23% of cases. In total, 182 patients were on adalimumab, of whom 68% had documentation of baseline disease severity, and 76% were reported as having inadequate response or contraindications to systemic treatments; 44% of patients continued on adalimumab despite having < 25% improvement in lesion count. CONCLUSION: UK dermatologists performed well against several audit standards, including documenting disease staging at baseline and smoking status. However, improvements are needed, particularly with regard to screening and management of comorbidities that could reduce the long-term complications associated with HS. A re-audit is required to evaluate changes in practice in the future.

Effects of acute dietary nitrate supplementation on cold-induced vasodilation in healthy males.

PURPOSE: Cold-induced vasodilation (CIVD) is a paradoxical rise in blood flow to the digits that occur during prolonged cold exposure. CIVD is thought to occur through active vasodilation and/or sympathetic withdrawal, where nitric oxide (NO) may play a key role in mediating these mechanisms. Beetroot juice (BRJ) is high in dietary nitrate (NO3-) which undergoes sequential reduction to nitrite (NO2-) and subsequently NO. Using a double-blind, randomized, crossover design, we examined the effect of acute BRJ supplementation on the CIVD response in 10 healthy males. METHODS: Participants had a resting blood pressure measurement taken prior to ingesting 140 mL of nitrate-rich BRJ (13 mmol NO3-) or a NO3--free placebo (PLA). After 2 h, participants immersed their hand in neutral water (~ 35 °C) for 10 min of baseline before cold water immersion (~ 8 °C) for 30 min. Laser-Doppler fluxmetry and skin temperature were measured continuously on the digits. RESULTS: Compared to PLA (100 ± 3 mmHg), acute BRJ supplementation significantly reduced mean arterial pressure at -30 min (96 ± 2 mmHg; p = 0.007) and 0 min (94 ± 2 mmHg; p = 0.008). Acute BRJ supplementation had no effect on Laser-Doppler fluxmetry during CIVD (expressed as cutaneous vascular conductance) measured as area under the curve (BRJ: 843 ± 148 PU mmHg-1 s; PLA: 1086 ± 333 PU mmHg-1 s), amplitude (BRJ: 0.60 ± 0.12 PU mmHg-1; PLA: 0.69 ± 0.14 PU mmHg-1), and duration (BRJ: 895 ± 60 s; PLA: 894 ± 46 s). CONCLUSION: Acute BRJ supplementation does not augment the CIVD response in healthy males.

National audit on the management of bullous pemphigoid.

BACKGROUND: Bullous pemphigoid (BP) is an autoimmune, subepidermal, blistering condition that typically affects elderly people. AIM: To undertake a national clinical audit based on standards derived from the British Association of Dermatologists (BAD) clinical guidelines on the management of BP. METHODS: In 2018, BAD members were invited to submit data for five consecutive adults with BP per centre, who had been under hospital supervision for at least 12 months, in a national audit over an 11-week period. RESULTS: In total, 123 responders from 120 hospitals provided data for 524 cases. Diagnosis was made either clinically (10.7%; 56 of 524) or through histology with direct immunofluorescence (41.6%; 218 of 524), indirect immunofluorescence (10.3%; 54 of 524) or both (37.4%; 196 of 524). Most patients had very mild baseline disease (63.9%; 225 of 352) with 21.9% (77 of 352) considered mild, 9.8% (31 of 352) moderate and 5.4% (19 of 352) severe. Documentation of diabetes, glycated haemoglobin (HbA1c), blood pressure and hypertension was available for 54.1% (283 of 523), 51% (267 of 524), 44.2% (231 of 522) and 61.5% (321 of 522) of cases, respectively. Oral corticosteroids were commenced in 85.5% (448 of 524) of patients, with 38.4% (172 of 448) of these having documented risk of osteoporosis; data regarding prescription of bone-protection therapies were available for 99.7% (447 of 448) of cases, with 75.6% (338 of 447) of these having a bone-protection prescription. Patient satisfaction was documented in 59.3% (310 of 523) of cases. Systemic treatment was commenced in 95.9% (502 of 524) of cases during the 12-month assessment period, with baseline blood test and follow-up data available for 96.6% (485 of 502) and 95.6% (480 of 502), respectively. Documentation of baseline blood tests was available for 87.4% (424 of 485) of cases, with follow-up tests recorded in 69.8% (335 of 480). CONCLUSION: Overall, compliance with elements of documentation was moderate or low, whereas standards pertaining to direct care were high.

BEECH: a dose-finding run-in followed by a randomised phase II study assessing the efficacy of AKT inhibitor capivasertib (AZD5363) combined with paclitaxel in patients with estrogen receptor-positive advanced or metastatic breast cancer, and in a PIK3CA mutant sub-population.

BACKGROUND: BEECH investigated the efficacy of capivasertib (AZD5363), an oral inhibitor of AKT isoforms 1-3, in combination with the first-line weekly paclitaxel for advanced or metastatic estrogen receptor-positive (ER+)/human epidermal growth factor receptor 2-negative (HER2-) breast cancer, and in a phosphoinositide 3-kinase, catalytic, alpha polypeptide mutation sub-population (PIK3CA+). PATIENTS AND METHODS: BEECH consisted of an open-label, phase Ib safety run-in (part A) in 38 patients with advanced breast cancer, and a randomised, placebo-controlled, double-blind, phase II expansion (part B) in 110 women with ER+/HER2- metastatic breast cancer. In part A, patients received paclitaxel 90 mg/m2 (days 1, 8 and 15 of a 28-day cycle) with capivasertib taken twice daily (b.i.d.) at two intermittent ascending dosing schedules. In part B, patients were randomly assigned, stratified by PIK3CA mutation status, to receive paclitaxel with either capivasertib or placebo. The primary end point for part A was safety to recommend a dose and schedule for part B; primary end points for part B were progression-free survival (PFS) in the overall and PIK3CA+ sub-population. RESULTS: Capivasertib was well tolerated, with a 400 mg b.i.d. 4 days on/3 days off treatment schedule selected in part A. In part B, median PFS in the overall population was 10.9 months with capivasertib versus 8.4 months with placebo [hazard ratio (HR) 0.80; P = 0.308]. In the PIK3CA+ sub-population, median PFS was 10.9 months with capivasertib versus 10.8 months with placebo (HR 1.11; P = 0.760). Based on the Common Terminology Criteria for Adverse Event v4.0, the most common grade ≥3 adverse events in the capivasertib group were diarrhoea, hyperglycaemia, neutropoenia and maculopapular rash. Dose intensity of paclitaxel was similar in both groups. CONCLUSIONS: Capivasertib had no apparent impact on the tolerability and dose intensity of paclitaxel. Adding capivasertib to weekly paclitaxel did not prolong PFS in the overall population or PIK3CA+ sub-population of ER+/HER2- advanced/metastatic breast cancer patients.ClinicalTrials.gov: NCT01625286.

A new method for the high-precision assessment of tumor changes in response to treatment.

Motivation: Imaging demonstrates that preclinical and human tumors are heterogeneous, i.e. a single tumor can exhibit multiple regions that behave differently during both development and also in response to treatment. The large variations observed in control group, tumors can obscure detection of significant therapeutic effects due to the ambiguity in attributing causes of change. This can hinder development of effective therapies due to limitations in experimental design rather than due to therapeutic failure. An improved method to model biological variation and heterogeneity in imaging signals is described. Specifically, linear Poisson modeling (LPM) evaluates changes in apparent diffusion co-efficient between baseline and 72 h after radiotherapy, in two xenograft models of colorectal cancer. The statistical significance of measured changes is compared to those attainable using a conventional t-test analysis on basic apparent diffusion co-efficient distribution parameters. Results: When LPMs were applied to treated tumors, the LPMs detected highly significant changes. The analyses were significant for all tumors, equating to a gain in power of 4-fold (i.e. equivalent to having a sample size 16 times larger), compared with the conventional approach. In contrast, highly significant changes are only detected at a cohort level using t-tests, restricting their potential use within personalized medicine and increasing the number of animals required during testing. Furthermore, LPM enabled the relative volumes of responding and non-responding tissue to be estimated for each xenograft model. Leave-one-out analysis of the treated xenografts provided quality control and identified potential outliers, raising confidence in LPM data at clinically relevant sample sizes. Availability and implementation: TINA Vision open source software is available from www.tina-vision.net. Supplementary information: Supplementary data are available at Bioinformatics online.

Structural identifiability for mathematical pharmacology: models of myelosuppression.

Structural identifiability is an often overlooked, but essential, prerequisite to the experiment design stage. The application of structural identifiability analysis to models of myelosuppression is used to demonstrate the importance of its considerations. It is shown that, under certain assumptions, these models are structurally identifiable and so drug and system specific parameters can truly be separated. Further it is shown via a meta-analysis of the literature that because of this the reported system parameter estimates for the "Friberg" or "Uppsala" model are consistent in the literature.

A tutorial on model informed approaches to cardiovascular safety with focus on cardiac repolarisation.

Drugs can affect the cardiovascular (CV) system either as an intended treatment or as an unwanted side effect. In both cases, drug-induced cardiotoxicities such as arrhythmia and unfavourable hemodynamic effects can occur, and be described using mathematical models; such a model informed approach can provide valuable information during drug development and can aid decision-making. However, in order to develop informative models, it is vital to understand CV physiology. The aims of this tutorial are to present (1) key background biological and medical aspects of the CV system, (2) CV electrophysiology, (3) CV safety concepts, (4) practical aspects of development of CV models and (5) regulatory expectations with a focus on using model informed and quantitative approaches to support nonclinical and clinical drug development. In addition, we share several case studies to provide practical information on project strategy (planning, key questions, assumptions setting, and experimental design) and mathematical models development that support decision-making during drug discovery and development.

A treatment algorithm for couples with unexplained infertility based on sperm chromatin assessment.

OBJECTIVE: To design a reproductive treatment algorithm based on the sperm DNA fragmentation (SDF) for couples with unexplained infertility following a poor intrauterine insemination (IUI) outcome. DESIGN: Couples that failed IUI with no apparent reproductive issue in both partners were allocated to diverse reproductive treatments on the basis of SDF. SETTING: Reproductive medical center in an academic setting. PATIENT(S): Over 4 years, couples with an unexpected poor IUI outcome and no apparent female or male partner reproductive issues were recruited. INTERVENTION(S): IUI, IVF, and ICSI were performed in the standard fashion following sperm SDF assays. MAIN OUTCOMES MEASURE(S): Fertilization rate, implantation rate, pregnancy characteristics, and delivery rates. RESULT(S): A total of 354 couples with unexplained infertility and normal semen parameters underwent 1133 IUI cycles. Clinical pregnancy rate (CPR) with IUI at our center in an age-matched cohort is 23.9% while the study cohort had 1.8%. Following SDF assessment, couples with failed IUI attempts but normal SDF (SCSA 9.8 ± 4.6%; TUNEL 11.8 ± 6.2%) underwent IVF with a CPR of 12.7%; those with abnormal SDF underwent ICSI with ejaculated spermatozoa, resulting in a CPR of 18.7%. This group included couples with normal SDF that had failed IVF. Couples with abnormal SDF that failed ICSI with ejaculated spermatozoa achieved a CPR of 31.0% with surgically retrieved spermatozoa. CONCLUSION(S): Couples with unexplained infertility that present with unexpectedly poor IUI outcomes can be funneled into a treatment algorithm guided by the integrity of the sperm genome for higher chances of pregnancy using an alternate method of insemination.

Intracytoplasmic sperm injection: state of the art in humans.

Among infertile couples, 25% involve both male and female factors, while male factor alone accounts for another 25% due to oligo-, astheno-, teratozoospermia, a combination of the three, or even a complete absence of sperm cells in the ejaculate and can lead to a poor prognosis even with the help of assisted reproductive technology (ART). Intracytoplasmic sperm injection (ICSI) has been with us now for a quarter of a century and in spite of the controversy generated since its inception, it remains in the forefront of the techniques utilized in ART. The development of ICSI in 1992 has drastically decreased the impact of male factor, resulting in millions of pregnancies worldwide for couples who, without ICSI, would have had little chance of having their own biological child. This review focuses on the state of the art of ICSI regarding utility of bioassays that evaluate male factor infertility beyond the standard semen analysis and describes the current application and advances in regard to ICSI, particularly the genetic and epigenetic characteristics of spermatozoa and their impact on reproductive outcome.

Compliance with national guidelines on isotretinoin: where are we 2 years since the last audit? Results of the National Isotretinoin Re-Audit 2014.

BACKGROUND: In 2010, the British Association of Dermatologists (BAD) published clinical guidelines for the safe introduction and continued use of isotretinoin in patients with acne in the UK. The BAD provides UK dermatologists with a facility for national audit, and it undertook an audit on compliance with these guidelines in 2012. AIM: To determine current clinical practices relating to use of isotretinoin among dermatologists in the UK (including geographical variations) as measured against BAD standards, and to ascertain any improvement since the 2012 audit. METHODS: The 2012 isotretinoin audit proforma was used, with additional questions on clinical setting, complaints and litigation. A web-based survey tool was used for data entry and submission, with email invitation to working, UK-based BAD members (n = 1226) in December 2013 and weekly reminders during the 8.5-week data collection period. Responders were requested to enter data for the three most recent consecutive patients (including one male and one female patient) who had completed treatment within the previous 6 months. RESULTS: In total, 338 (27.6%) respondents provided data on 1013 patients. Serum lipids were checked in 93.4% of patients and documentation of mental health and/or mood state was recorded in 82.1%. Regarding the Pregnancy Prevention Programme (PPP), 91.6% of female patients of childbearing potential had signed the PPP information form, while 93.3% who had followed the PPP had taken pregnancy tests both before and during treatment, and 54.7% had taken a pregnancy test 5 weeks post-treatment. CONCLUSION: Overall, there is currently good compliance with standards. Certain aspects of care that are less frequently preformed, such as pregnancy testing post-treatment, are highlighted.

British Association of Dermatologists' national audit on nonmelanoma skin cancer excision, 2014.

BACKGROUND: Diagnosis and management of nonmelanoma skin cancer (NMSC) represents a large part of the dermatology workload, and complete excision is a required surgical standard for treatment. AIM: To conduct an audit of the surgical practice for the treatment of NMSC by dermatologists in the UK. METHODS: Data on 10 consecutive nonmicrographic excisions of nonmelanoma skin cancer by UK dermatologists. Data collected included site, preoperative diagnosis, histological diagnosis, proximity to previous scars, and histological deep and peripheral margins. RESULTS: A total of 227 responses from 135 centres reported 2739 excisions. Excisions on the head and neck accounted for 58.3% of cases. Tumour diameter (mean ± SD) was 10.61 ± 6.9 mm (maximum 130 mm), and 96.7% of cases were primary excisions, with 3.3% being re-excisions. Basal cell carcinomas (BCCs) accounted for 79.1% (n = 2167) of the total cases and squamous cell carcinomas (SCCs) for 17.9% n = 491). Of the suspected BCCs and SCCS, 94.4% (n = 2045) and 66.8% (328), respectively, were confirmed histologically to be the respective carcinomas. Similar proportions of BCC and SCC cases were within 10 mm of a previous excision. Lateral and deep margins were clear in 98.3% and 99.2% of BCC cases, respectively, and in 98.4% and 97.1% of SCC cases, respectively. Reported surgical complication rate in the audit was 3.4%. CONCLUSIONS: The majority of excisions for NMSC are for BCC and SCC. Our figures for diagnostic accuracy are at the upper range of previously published figures. Most patients were not followed up in secondary care, hence complication rates may be under-reported.