Application of the matched nested case-control design to the secondary analysis of trial data

Background: A nested case-control study is an efficient design that can be embedded within an existing cohort study or randomised trial. It has a number of advantages compared to the conventional case-control design, and has the potential to answer important research questions using untapped prospectively collected data. Methods: We demonstrate the utility of the matched nested case-control design by applying it to a secondary analysis of the Abnormal Doppler Enteral Prescription Trial. We investigated the role of milk feed type and changes in milk feed type in the development of necrotising enterocolitis in a group of 398 high risk growth-restricted preterm infants. Results: Using matching, we were able to generate a comparable sample of controls selected from the same population as the cases. In contrast to the standard case-control design, exposure status was ascertained prior to the outcome event occurring and the comparison between the cases and matched controls could be made at the point at which the event occurred. This enabled us to reliably investigate the temporal relationship between feed type and necrotising enterocolitis. Conclusions: A matched nested case-control study can be used to identify credible associations in a secondary analysis of clinical trial data where the exposure of interest was not randomised, and has several advantages over a standard case-control design. This method offers the potential to make reliable inferences in scenarios where it would be unethical or impractical to perform a randomised clinical trial.</br

E-Freeze - a randomised controlled trial evaluating the clinical and cost effectiveness of a policy of freezing embryos followed by thawed frozen embryo transfer compared with a policy of fresh embryo transfer, in women undergoing in vitro fertilisation : a statistical analysis plan

The E-Freeze Collaborators Group contributed to the overall design of the E-Freeze trial. We would like to thank the Data Monitoring Committee, particularly Professor Elizabeth Allen, and Charles Opondo for their helpful comments and guidance on the statistical analysis plan.Peer reviewe

Safety and efficacy of 2% chlorhexidine gluconate aqueous versus 2% chlorhexidine gluconate in 70% isopropyl alcohol for skin disinfection prior to percutaneous central venous catheter insertion in preterm neonates:The ARCTIC randomised-controlled feasibility trial protocol

Introduction Catheter-related sepsis is one of the most dangerous complications of neonatal intensive care and is associated with significant morbidity and mortality. Use of catheter-care € bundles' has reduced the incidence of catheter-related sepsis, although individual components have not been well studied. Better evidence is needed to guide selection of the most appropriate antiseptic solution for skin disinfection in preterm neonates. This study will inform the feasibility and design of the first randomised controlled trial to examine the safety and efficacy of alcohol-based versus aqueous-based chlorhexidine antiseptic formulations for skin disinfection prior to percutaneous central venous catheterisation in preterm neonates. The antiseptics to be compared are 2% chlorhexidine gluconate (CHG) aqueous and 2% CHG in 70% isopropyl alcohol. Methods and analysis The Antiseptic Randomised Controlled Trial for Insertion of Catheters (ARCTIC) is a two-centre randomised-controlled feasibility trial. At least 100 preterm infants born at <34 weeks' gestation and due to undergo percutaneous insertion of a central venous catheter will be randomly allocated to receive prior skin disinfection with one of the two antiseptic solutions. Outcomes include: i) recruitment and retention rates; ii) completeness of data collection; iii) numbers of enrolled infants meeting case definitions for definite catheter-related sepsis, catheter-associated sepsis and catheter colonisation and iv) safety outcomes of skin morbidity scores recorded daily from catheter insertion until 48 hours post removal. The key feasibility metrics will be reported as proportions with 95% CIs. Estimated prevalence of catheter colonisation will allow calculation of sample size for the large-scale trial. The data will inform whether it will be feasible to progress to a large-scale trial. Ethics and dissemination ARCTIC has been approved by the National Health Service Health Research Authority National Research Ethics Service Committee East of England (Cambridge South) (IRAS ID 163868), was adopted onto the National Institute of Health Research Clinical Research Network portfolio (CPMS ID 19899) and is registered with an International Standard Randomised Control Trials Number (ISRCTN: 82571474; Pre-results) and European Clinical Trials Database number 2015-000874-36. Dissemination plans include presentations at scientific conferences, scientific publications and sharing of the findings with parents via the support of Bliss baby charity

Involving users in the design of a randomised controlled trial of an intervention to promote early presentation in breast cancer: Qualitative study

Background: The purpose of this study was to explore women's views of the design of a large pragmatic cost-effectiveness randomised controlled trial of the policy of offering a health professional-delivered intervention to promote early presentation with breast symptoms in older women and thereby improve survival, with a view to informing protocol development. The trial will recruit over 100,000 healthy women aged 67+, and outcome data will be collected on those who develop breast cancer. The scale of the trial and the need for long-term follow-up presented a number of design challenges in relation to obtaining consent, ascertaining and contacting participants who developed breast cancer, and collecting outcome data. Methods: Qualitative study involving 69 women participating in 7 focus groups and 17 in-depth interviews. 15 women had a previous diagnosis of breast cancer and 54 did not. Results: The women held strong views and had a good understanding of the rationale of the design of clinical trials. The women recognised that in a very large trial with long-term follow-up it was necessary to incorporate design features to make the trial feasible and efficient. Most strikingly, they supported the idea of opt-out consent and identifying women with breast cancer using routine datasets. Conclusions: This model of user involvement engaged women well with the design challenges of the trial and led to improvements to the protocol. The study strengthens the case for user involvement, in particular through focus groups and in-depth interviews, in the design of trials

Prigodom 60-godišnjice zadružne mlekarne u Škofjoj Loki

Background The Parent Report of Children's Abilities–Revised (PARCA-R) can be used to identify preterm born children at risk for developmental delay at age 24 months. However, standardised scores for assessing all children in the general population and quantifying development relative to the norm are unavailable, thus limiting the use of the questionnaire. We aimed to develop scores that are standardised by age and sex for the PARCA-R to assess children's cognitive and language development at age 24–27 months. Methods Anonymised data from PARCA-R questionnaires that were completed by parents of 2-year-old children in three previous studies were obtained to form a standardisation sample that was representative of the UK general population. Anonymised data were obtained from three further studies to assess the external validity and clinical validity of the standardised scores. We used the lambda-mu-sigma (lambda for skewness, mu for median, sigma for the coefficient of variation) method to develop scores that are standardised by age and sex for three scales (non-verbal cognitive development, language development, and total parent report composite [PRC]) for children in four 1-month age bands, spanning age 23·5–27·5 months. Findings We included 6402 children (mean age 25 months and 1 day [range 23 months and 16 days to 27 months and 15 days]) in the standardisation sample and 709 (mean age 24 months and 19 days [23 months and 16 days to 27 months and 15 days]) to test the external validity and 1456 (mean age 24 months and 8·5 days [23 months and 16 days to 27 months and 15 days]) to test the clinical validity of the standardised scores. For all PARCA-R scales, mean standardised scores approximated 100 (SD 15) in both sexes and all age groups. These scores were independent of socioeconomic status. Standardised scores were close to 100 (15) in the external validation sample, showing the validity of the scores. Standardised scores for the total PRC scale for children born very preterm (<32 weeks' gestation) were 0·47 SD lower on average than the normative mean, and for children with neonatal sepsis were 0·73 SD lower on average than the normative mean. These scores were equivalent to a standardised score of 93 (95% CI 91–94) for children born very preterm and 89 (88–91) for children with neonatal sepsis, thus showing clinical validity. Interpretation The PARCA-R provides a norm-referenced, standardised assessment of cognitive and language development at 24–27 months of age. The questionnaire is available non-commercially in English with translations available in 14 other languages, thus providing clinicians and researchers with a cost-effective tool for assessing development and identifying children with delay

Two-year follow-up of infant and maternal outcomes after planned early delivery or expectant management for late preterm pre-eclampsia (PHOENIX): a randomised controlled trial

OBJECTIVE: We evaluated the best time to initiate delivery in late preterm pre-eclampsia in order to optimise long-term infant and maternal outcomes. DESIGN: Parallel-group, non-masked, randomised controlled trial SETTING: 46 UK maternity units POPULATION: Women with pre-eclampsia between 34+0 and 36+6 weeks' gestation, without severe disease, were randomised to planned delivery or expectant management. PRIMARY LONG-TERM OUTCOME: Infant neurodevelopmental outcome at 2 years of age, using the PARCA-R (Parent Report of Children's Abilities-Revised) composite score. RESULTS: Between Sept 29, 2014, and Dec 10, 2018, 901 women were enrolled in the trial, with 450 allocated to planned delivery and 451 to expectant management. At 2-year follow-up, the intention-to-treat analysis population included 276 women (290 infants) allocated to planned delivery and 251 women (256 infants) to expectant management. The mean composite standardised PARCA-R scores were 89.5 (standard deviation (SD) 18.2) in the planned delivery group and 91.9 (SD 18.4) in the expectant management group, with an adjusted mean difference of -2.4 (95% CI -5.4 to 0.5) points. CONCLUSION: In infants of women with late preterm pre-eclampsia, average neurodevelopmental assessment at 2 years lies within the normal range, regardless of whether planned delivery or expectant management is pursued. Because of lower than anticipated follow-up, there was limited power to demonstrate these scores were not different, but the small between-group difference in PARCA-R scores is unlikely to be clinically important

Promoting Early Presentation intervention sustains increased breast cancer awareness in older women for three years: A randomized controlled trial

Objective In a randomized controlled trial, the Promoting Early Presentation intervention increased older women’s breast cancer awareness after two years. We investigated whether this increase was sustained at three years, and the effect on breast screening self-referral. Methods We randomly allocated 867 women attending their final invited breast screening appointment to the Promoting Early Presentation intervention or usual care. We examined breast cancer awareness after three years and breast screening self-referrals after four years. Results Women in the Promoting Early Presentation intervention arm had higher breast cancer awareness at three years than the usual care arm (odds ratio: 10.4; 95% confidence interval: 3.1 to 34.8). There were no differences in proportions self-referring for breast screening between arms, but statistical power was limited. Conclusion The Promoting Early Presentation intervention has a sustained effect on breast cancer awareness in older women. The effect on self-referral for breast screening is unclear

Economic evaluation alongside the Speed of Increasing milk Feeds Trial (SIFT)

OBJECTIVE: To evaluate the cost-effectiveness of two rates of enteral feed advancement (18 vs 30 mL/kg/day) in very preterm and very low birth weight infants. DESIGN: Within-trial economic evaluation alongside a multicentre, two-arm parallel group, randomised controlled trial (Speed of Increasing milk Feeds Trial). SETTING: 55 UK neonatal units from May 2013 to June 2015. PATIENTS: Infants born <32 weeks' gestation or <1500 g, receiving less than 30 mL/kg/day of milk at trial enrolment. Infants with a known severe congenital anomaly, no realistic chance of survival, or unlikely to be traceable for follow-up, were ineligible. INTERVENTIONS: When clinicians were ready to start advancing feed volumes, infants were randomised to receive daily increments in feed volume of 30 mL/kg (intervention) or 18 mL/kg (control). MAIN OUTCOME MEASURE: Cost per additional survivor without moderate to severe neurodevelopmental disability at 24 months of age corrected for prematurity. RESULTS: Average costs per infant were slightly higher for faster feeds compared with slower feeds (mean difference £267, 95% CI -6928 to 8117). Fewer infants achieved the principal outcome of survival without moderate to severe neurodevelopmental disability at 24 months in the faster feeds arm (802/1224 vs 848/1246). The stochastic cost-effectiveness analysis showed a likelihood of worse outcomes for faster feeds compared with slower feeds. CONCLUSIONS: The stochastic cost-effectiveness analysis shows faster feeds are broadly equivalent on cost grounds. However, in terms of outcomes at 24 months age (corrected for prematurity), faster feeds are harmful. Faster feeds should not be recommended on either cost or effectiveness grounds to achieve the primary outcome

Prophylactic antibiotics in the prevention of infection after operative vaginal delivery (ANODE): a multicentre randomised controlled trial

Background Risk factors for maternal infection are clearly recognised, including caesarean section and operative vaginal birth. Antibiotic prophylaxis at caesarean section is widely recommended because there is clear systematic review evidence that it reduces incidence of maternal infection. Current WHO guidelines do not recommend routine antibiotic prophylaxis for women undergoing operative vaginal birth because of insufficient evidence of effectiveness. We aimed to investigate whether antibiotic prophylaxis prevented maternal infection after operative vaginal birth. Methods In a blinded, randomised controlled trial done at 27 UK obstetric units, women (aged ≥16 years) were allocated to receive a single dose of intravenous amoxicillin and clavulanic acid or placebo (saline) following operative vaginal birth at 36 weeks gestation or later. The primary outcome was confirmed or suspected maternal infection within 6 weeks of delivery defined by a new prescription of antibiotics for specific indications, confirmed systemic infection on culture, or endometritis. We did an intention-to-treat analysis. This trial is registered with ISRCTN, number 11166984, and is closed to accrual. Findings Between March 13, 2016, and June 13, 2018, 3427 women were randomly assigned to treatment: 1719 to amoxicillin and clavulanic acid, and 1708 to placebo. Seven women withdrew, leaving 1715 in the amoxicillin and clavulanic acid group and 1705 in the placebo groups. Primary outcome data were missing for 195 (6%) women. Significantly fewer women allocated to amoxicillin and clavulanic acid had a confirmed or suspected infection (180 [11%] of 1619) than women allocated to placebo (306 [19%] of 1606; risk ratio 0·58, 95% CI 0·49–0·69; p<0·0001). One woman in the placebo group reported a skin rash and two women in the amoxicillin and clavulanic acid reported other allergic reactions, one of which was reported as a serious adverse event. Two other serious adverse events were reported, neither was considered causally related to the treatment. Interpretation This trial shows benefit of a single dose of prophylactic antibiotic after operative vaginal birth and guidance from WHO and other national organisations should be changed to reflect this