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Featured researches published by J Snowball.


International Journal of Epidemiology | 2011

Inequalities in participation in an organized national colorectal cancer screening programme: results from the first 2.6 million invitations in England

Christian von Wagner; Gianluca Baio; Rosalind Raine; J Snowball; Stephen Morris; Wendy Atkin; Austin Obichere; G Handley; Richard F. Logan; Sandra Rainbow; Stephen Smith; Stephen P. Halloran; Jane Wardle

BACKGROUND An organized, population-based, colorectal cancer screening programme was initiated in England in 2006 offering biennial faecal occult blood testing (FOBT) to adults aged 60-69 years. Organized screening programmes with no associated financial costs to the individual should minimize barriers to access for lower socio-economic status (SES) groups. However, SES differences in uptake were observed in the pilot centres of the UK programme, so the aim of this analysis was to identify the extent of inequalities in uptake by SES, ethnic diversity, gender and age in the first 28 months of the programme. Design Cross-sectional analysis of colorectal cancer screening uptake data. METHODS Between October 2006 and January 2009, over 2.6 million adults aged 60-69 years were mailed a first FOBT kit by the five regional screening hubs. Uptake was defined as return of a test kit within 13 weeks. We used multivariate generalized linear regression to examine variation by area-based socioeconomic deprivation, area-based ethnicity, gender and age. RESULTS Uptake was 54%, but showed a gradient across quintiles of deprivation, ranging from 35% in the most deprived quintile to 61% in the least deprived. Multivariate analyses confirmed an independent effect of deprivation, with stronger effects in women and older people. The most ethnically diverse areas also had lower uptake (38%) than other areas (52-58%) independent of SES, age, gender and regional screening hub. Ethnic disparities were more pronounced in men but equivalent across age groups. More women than men returned a kit (56 vs 51%), but there was also an interaction with age, with uptake increasing with age in men (49% at 60-64 years; 53% at 65-69 years) but not women (57 vs 56%). CONCLUSIONS Overall uptake rates in this organized screening programme were encouraging, but nonetheless there was low uptake in the most ethnically diverse areas and a striking gradient by SES. Action to promote equality of uptake is needed to avoid widening inequalities in cancer mortality.


Gut | 2015

Colorectal cancer screening uptake over three biennial invitation rounds in the English bowel cancer screening programme

Siu Hing Lo; Stephen P. Halloran; J Snowball; Helen E. Seaman; Jane Wardle; Christian von Wagner

Objective To examine patterns of colorectal cancer (CRC) screening uptake over three biennial invitation rounds in the National Health Service (NHS) Bowel Cancer Screening Programme (BCSP) in England. Methods We analysed data from the BCSPs Southern Hub for individuals (n=62 099) aged 60–64 years at the time of first invitation to screening with a follow-up period that allowed for two further biennial invitations. Data on sex, age and a neighbourhood-level measure of socioeconomic deprivation were used in the analysis. Outcomes included uptake of guaiac-based faecal occult blood (gFOB) test screening, inadequate gFOB screening (≥1 test kit(s) returned but failed to complete further gFOB tests needed to reach a conclusive test result), test positivity, compliance with follow-up examinations (usually colonoscopy) and diagnostic outcomes. Results Overall gFOB uptake was 57.4% in the first, 60.9% in the second and 66.2% in third biennial invitation round. This resulted in 70.1% of the initial cohort having responded at least once, 60.7% at least twice and 44.4% three times. Participation in the first round was strongly predictive of participation in the second round (‘Previous Responders’: 86.6% vs ‘Previous Non-Responders’: 23.1%). Participation in the third round was highest among ‘Consistent Screeners’ (94.5%), followed by ‘Late Entrants’ (78.0%), ‘Dropouts’ (59.8%) and ‘Consistent Non-Responders’ (14.6%). Socioeconomic inequalities in uptake were observed across the three rounds, but sex inequalities decreased over rounds. Inadequate gFOB screening was influenced by screening history and socioeconomic deprivation. Screening history was the only significant predictor of follow-up compliance. Conclusions Screening history is associated with overall gFOB uptake, inadequate gFOB screening and follow-up compliance. Socioeconomic deprivation is also consistently associated with lower gFOB uptake and inadequate gFOB screening. Improving regular screening among identified ‘at-risk’ groups is important for the effectiveness of CRC screening programmes.


The Lancet | 2016

Effects of evidence-based strategies to reduce the socioeconomic gradient of uptake in the English NHS Bowel Cancer Screening Programme (ASCEND): four cluster-randomised controlled trials

Jane Wardle; Christian von Wagner; Ines Kralj-Hans; Stephen P. Halloran; Samuel G. Smith; Lm McGregor; Gemma Vart; R Howe; J Snowball; G Handley; Richard F. Logan; Sandra Rainbow; Steve Smith; M Thomas; Nicholas Counsell; Steve Morris; Stephen W. Duffy; Allan Hackshaw; Sue Moss; Wendy Atkin; Rosalind Raine

Summary Background Uptake in the national colorectal cancer screening programme in England varies by socioeconomic status. We assessed four interventions aimed at reducing this gradient, with the intention of improving the health benefits of screening. Methods All people eligible for screening (men and women aged 60–74 years) across England were included in four cluster-randomised trials. Randomisation was based on day of invitation. Each trial compared the standard information with the standard information plus the following supplementary interventions: trial 1 (November, 2012), a supplementary leaflet summarising the gist of the key information; trial 2 (March, 2012), a supplementary narrative leaflet describing peoples stories; trial 3 (June, 2013), general practice endorsement of the programme on the invitation letter; and trial 4 (July–August, 2013) an enhanced reminder letter with a banner that reiterated the screening offer. Socioeconomic status was defined by the Index of Multiple Deprivation score for each home address. The primary outcome was the socioeconomic status gradient in uptake across deprivation quintiles. This study is registered, number ISRCTN74121020. Findings As all four trials were embedded in the screening programme, loss to follow-up was minimal (less than 0·5%). Trials 1 (n=163 525) and 2 (n=150 417) showed no effects on the socioeconomic gradient of uptake or overall uptake. Trial 3 (n=265 434) showed no effect on the socioeconomic gradient but was associated with increased overall uptake (adjusted odds ratio [OR] 1·07, 95% CI 1·04–1·10, p<0·0001). In trial 4 (n=168 480) a significant interaction was seen with socioeconomic status gradient (p=0·005), with a stronger effect in the most deprived quintile (adjusted OR 1·11, 95% CI 1·04–1·20, p=0·003) than in the least deprived (1·00, 0·94–1·06, p=0·98). Overall uptake was also increased (1·07, 1·03–1·11, p=0·001). Interpretation Of four evidence-based interventions, the enhanced reminder letter reduced the socioeconomic gradient in screening uptake, but further reducing inequalities in screening uptake through written materials alone will be challenging. Funding National Institute for Health Research.


British Journal of Cancer | 2012

Socioeconomic variation in uptake of colonoscopy following a positive faecal occult blood test result: a retrospective analysis of the NHS Bowel Cancer Screening Programme

Steve Morris; Gianluca Baio; E Kendall; C von Wagner; Jane Wardle; Wendy Atkin; Stephen P. Halloran; G Handley; Richard F. Logan; Austin Obichere; Sandra Rainbow; Samuel D. Smith; J Snowball; Rosalind Raine

Background:Bowel cancer is a serious health burden and its early diagnosis improves survival. The Bowel Cancer Screening Programme (BCSP) in England screens with the Faecal Occult Blood test (FOBt), followed by colonoscopy for individuals with a positive test result. Socioeconomic inequalities have been demonstrated for FOBt uptake, but it is not known whether they persist at the next stage of the screening pathway. The aim of this study was to assess the association between colonoscopy uptake and area socioeconomic deprivation, controlling for individual age and sex, and area ethnic diversity, population density, poor self-assessed health, and region.Methods:Logistic regression analysis of colonoscopy uptake using BCSP data for England between 2006 and 2009 for 24 180 adults aged between 60 and 69 years.Results:Overall colonoscopy uptake was 88.4%. Statistically significant variation in uptake is found between quintiles of area deprivation (ranging from 86.4 to 89.5%), as well as age and sex groups (87.9–89.1%), quintiles of poor self-assessed health (87.5–89.5%), non-white ethnicity (84.6–90.6%) and population density (87.9–89.3%), and geographical regions (86.4–90%).Conclusion:Colonoscopy uptake is high. The variation in uptake by socioeconomic deprivation is small, as is variation by subgroups of age and sex, poor self-assessed health, ethnic diversity, population density, and region.


Gut | 2017

Increased uptake and improved outcomes of bowel cancer screening with a faecal immunochemical test: results from a pilot study within the national screening programme in England

Sue Moss; Christopher Mathews; T J Day; Steve Smith; Helen E. Seaman; J Snowball; Stephen P. Halloran

Background The National Health Service Bowel Cancer Screening Programme (BCSP) in England uses a guaiac-based faecal occult blood test (gFOBt). A quantitative faecal immunochemical test (FIT) for haemoglobin (Hb) has many advantages, including being specific for human blood, detecting Hb at a much lower concentration with a single faecal sample and improved uptake. Methods In 2014, a large comparative pilot study was performed within BCSP to establish the acceptability and diagnostic performance of FIT. Over a 6-month period, 40 930 (1 in 28) subjects were sent a FIT (OC-SENSOR) instead of a gFOBt. A bespoke FIT package was used to mail FIT sampling devices to and from FIT subjects. All participants positive with either gFOBt or FIT (cut-off 20 µg Hb/g faeces) were referred for follow-up. Subgroup analysis included cut-off concentrations, age, sex, screening history and deprivation quintile. Results While overall uptake increased by over 7 percentage points with FIT (66.4% vs 59.3%, OR 1.35, 95% CI 1.33 to 1.38), uptake by previous non-responders almost doubled (FIT 23.9% vs gFOBt 12.5%, OR 2.20, 95% CI 2.10 to 2.29). The increase in overall uptake was significantly higher in men than women and was observed across all deprivation quintiles. With the conventional 20 µg/g cut-off, FIT positivity was 7.8% and ranged from 5.7% in 59–64-year-old women to 11.1% in 70–75-year-old men. Cancer detection increased twofold and that for advanced adenomas nearly fivefold. Detection rates remained higher with FIT for advanced adenomas, even at 180 µg Hb/g. Conclusions Markedly improved participation rates were achieved in a mature gFOBt-based national screening programme and disparities between men and women were reduced. High positivity rates, particularly in men and previous non-respondents, challenge the available colonoscopy resource, but improvements in neoplasia detection are still achievable within this limited resource.


British Journal of Cancer | 2016

Impact of general practice endorsement on the social gradient in uptake in bowel cancer screening

Rosalind Raine; Stephen W. Duffy; Jane Wardle; Francesca Solmi; Steve Morris; R Howe; Ines Kralj-Hans; J Snowball; Nicholas Counsell; Stephen J. Moss; Allan Hackshaw; C von Wagner; Gemma Vart; Lm McGregor; Samuel G. Smith; Stephen P. Halloran; G Handley; Richard F. Logan; Sandra Rainbow; Samuel D. Smith; M Thomas; Wendy Atkin

Background:There is a socioeconomic gradient in the uptake of screening in the English NHS Bowel Cancer Screening Programme (BCSP), potentially leading to inequalities in outcomes. We tested whether endorsement of bowel cancer screening by an individual’s general practice (GP endorsement; GPE) reduced this gradient.Methods:A cluster-randomised controlled trial. Over 20 days, individuals eligible for screening in England from 6480 participating general practices were randomly allocated to receive a GP-endorsed or the standard invitation letter. The primary outcome was the proportion of people adequately screened and its variation by quintile of Index of Multiple Deprivation.Results:We enrolled 265 434 individuals. Uptake was 58.2% in the intervention arm and 57.5% in the control arm. After adjusting for age, sex, hub and screening episode, GPE increased the overall odds of uptake (OR=1.07, 95% CI 1.04–1.10), but did not affect its socioeconomic gradient. We estimated that implementing GPE could result in up to 165 more people with high or intermediate risk colorectal adenomas and 61 cancers detected, and a small one-off cost to modify the standard invitation (£78 000).Conclusions:Although GPE did not improve its socioeconomic gradient, it offers a low-cost approach to enhancing overall screening uptake within the NHS BCSP.


British Journal of Cancer | 2015

Predictors of repeat participation in the NHS bowel cancer screening programme.

Siu Hing Lo; Stephen P. Halloran; J Snowball; Helen E. Seaman; Jane Wardle; C von Wagner

Objectives:Most types of population-based cancer screening require repeat participation to be effective. This study investigated predictors of repeat participation in the NHS Bowel Cancer Screening Programme (BCSP).Methods:The BCSP in England offers biennial colorectal cancer screening using a guaiac fecal occult blood test (gFOBt) from age 60–74 years. This analysis included 62 081 individuals aged 60–64 years at the time of the first invitation (R1). The main outcome was repeat participation at their second (R2) or third (R3) invitation. Behavioural measures derived from screening records included late return of the gFOBt kit, compliance with follow-up investigations and previous screening participation. Other potential predictors of repeat participation included results of individual test kit analysis (normal, weak positive, strong positive, spoilt) and the definitive result of the gFOBt screening episode (normal or abnormal). Age, sex and socioeconomic deprivation were also recorded.Results:Overall repeat uptake was 86.6% in R2 and 88.6% in R3. Late return of the test kit was consistently associated with lower uptake (R2: 82.3% vs 88.6%, P<0.001; R3: 84.5% vs 90.5%, P<0.001). A definitive abnormal gFOBt result in the previous screening episode was a negative predictor of repeat uptake (R2: 61.4% vs 86.8%, P<0.001; R3: 65.7% vs 88.8%, P<0.001). Weak positive (R2: 76.9% vs 86.8%, P<0.001; R3: 81.7% vs 88.8%, P<0.05) and spoilt test kits (R2: 79.0% vs 86.6%, NS; R3: 84.2% vs 92.2%, P<0.05) were associated with lower repeat uptake, but were not consistently independent predictors in all invitation rounds or subgroups. Among those with a definitive abnormal gFOBt result, noncompliance with follow-up in a previous screening episode was also associated with lower repeat uptake (R2: 24.3% vs 67.1%, P<0.001; R3: 43.2% vs 69.9%, P<0.001).Conclusions:Behavioural markers and test results from previous screening episodes have been implicated in subsequent gFOBt uptake.


Journal of Medical Screening | 2012

The impact of media coverage of the Flexible Sigmoidoscopy Trial on English colorectal screening uptake

Siu Hing Lo; Gemma Vart; J Snowball; Stephen P. Halloran; Jane Wardle; C von Wagner

Objective To assess the impact of media coverage of the UK Flexible Sigmoidoscopy Trial on colorectal screening uptake in England. Setting In April 2010, publication of the UK Flexible Sigmoidoscopy (FS) Trial results generated considerable media interest in both FS and colorectal cancer (CRC) generally. Methods We used routinely collected data from the south of England (excluding London) to analyse return of faecal occult blood test (FOBt) kits within 28 days of the invitation (early uptake) among 60–69 year olds, before (T1, n = 31,229), around the time of (T2, n = 39,571), and one month after (T3, n = 33,430) the FS publicity. Results FOBt uptake over the whole period was 58.2%, with 38.4% of the kits returned within 28 days (early uptake). Across the three time periods, early uptake was 35.8% at T1, 39.4% at T2, and 39.7% at T3. Multivariate regression controlling for age, gender and socioeconomic status confirmed that uptake was higher if people received the FOBt kit around the time of the media coverage (T2: odds ratio [OR] = 1.17, 95% CI = 1.13–1.20), or one month after (T3: OR = 1.18, 95% CI = 1.15–1.22) than before (T1). Sub-group analyses demonstrated that the impact was stronger among previous non-responders than among first-time invitees or previous responders (P < 0.001). Conclusion Media coverage of the FS Trial appeared to have a small but positive impact on FOBt screening uptake, especially among people who had previously abstained from screening.


Gastroenterology Research and Practice | 2016

Reducing the Social Gradient in Uptake of the NHS Colorectal Cancer Screening Programme Using a Narrative-Based Information Leaflet: A Cluster-Randomised Trial

Lm McGregor; C von Wagner; Wendy Atkin; Ines Kralj-Hans; Stephen P. Halloran; G Handley; Richard F. Logan; Sandra Rainbow; Samuel D. Smith; J Snowball; M Thomas; Samuel G. Smith; Gemma Vart; R Howe; Nicholas Counsell; Allan Hackshaw; Steve Morris; Stephen W. Duffy; Rosalind Raine; Jane Wardle

Objective. To test the effectiveness of adding a narrative leaflet to the current information material delivered by the NHS English colorectal cancer (CRC) screening programme on reducing socioeconomic inequalities in uptake. Participants. 150,417 adults (59–74 years) routinely invited to complete the guaiac Faecal Occult Blood test (gFOBt) in March 2013. Design. A cluster randomised controlled trial (ISRCTN74121020) to compare uptake between two arms. The control arm received the standard NHS CRC screening information material (SI) and the intervention arm received the standard information plus a supplementary narrative leaflet, which had previously been shown to increase screening intentions (SI + N). Between group comparisons were made for uptake overall and across socioeconomic status (SES). Results. Uptake was 57.7% and did not differ significantly between the two trial arms (SI: 58.5%; SI + N: 56.7%; odds ratio = 0.93; 95% confidence interval: 0.81–1.06; p = 0.27). There was no interaction between group and SES quintile (p = 0.44). Conclusions. Adding a narrative leaflet to existing information materials does not reduce the SES gradient in uptake. Despite the benefits of using a pragmatic trial design, the need to add to, rather than replace, existing information may have limited the true value of an evidence-based intervention on behaviour.


British Journal of Cancer | 2016

Factors associated with completion of bowel cancer screening and the potential effects of simplifying the screening test algorithm

Benjamin Kearns; Sophie Whyte; Helen E. Seaman; J Snowball; Stephen P. Halloran; Piers Butler; Julietta Patnick; Claire Nickerson; Jim Chilcott

Background:The primary colorectal cancer screening test in England is a guaiac faecal occult blood test (gFOBt). The NHS Bowel Cancer Screening Programme (BCSP) interprets tests on six samples on up to three test kits to determine a definitive positive or negative result. However, the test algorithm fails to achieve a definitive result for a significant number of participants because they do not comply with the programme requirements. This study identifies factors associated with failed compliance and modifications to the screening algorithm that will improve the clinical effectiveness of the screening programme.Methods:The BCSP Southern Hub data for screening episodes started in 2006–2012 were analysed for participants aged 60–69 years. The variables included age, sex, level of deprivation, gFOBt results and clinical outcome.Results:The data set included 1 409 335 screening episodes; 95.08% of participants had a definitively normal result on kit 1 (no positive spots). Among participants asked to complete a second or third gFOBt, 5.10% and 4.65%, respectively, failed to return a valid kit. Among participants referred for follow up, 13.80% did not comply. Older age was associated with compliance at repeat testing, but non-compliance at follow up. Increasing levels of deprivation were associated with non-compliance at repeat testing and follow up. Modelling a reduction in the threshold for immediate referral led to a small increase in completion of the screening pathway.Conclusions:Reducing the number of positive spots required on the first gFOBt kit for referral for follow-up and targeted measures to improve compliance with follow-up may improve completion of the screening pathway.

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Jane Wardle

University College London

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Wendy Atkin

Imperial College London

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Rosalind Raine

University College London

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C von Wagner

University College London

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Steve Morris

University College London

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Gemma Vart

University College London

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