Comparing the effectiveness and cost-effectiveness of text-message reminders and telephone patient navigation to improve the uptake of faecal immunochemical test screening among non-responders in London: a randomised controlled trial protocol.

INTRODUCTION: Participation in bowel cancer screening is lower in regions where there is high ethnic diversity and/or socioeconomic deprivation. Interventions, such as text message reminders and patient navigation (PN), have the potential to increase participation in these areas. As such, there is interest in the comparative effectiveness of these interventions to increase bowel cancer screening participation, as well as their relative cost-effectiveness. METHODS AND ANALYSIS: This study will use a three-arm randomised controlled trial design to compare the effectiveness and cost-effectiveness of text message reminders and PN to increase the uptake of bowel cancer screening in London. Participants will be individuals who have not returned a completed faecal immunochemical test kit within 13 weeks of receiving a routine invitation from the London bowel cancer screening hub. Participants will be randomised (in a 1:1:1 ratio) to receive either (1) usual care (ie, 'no intervention'), (2) a text message reminder at 13 weeks, followed by repeated text message reminders at 15, 17 and 19 weeks (in the event of non-response) or (3) a text message reminder at 13 weeks, followed by PN telephone calls at 15, 17 and 19 weeks in the event of non-response. The primary endpoint will be participation in bowel cancer screening, defined as 'the return of a completed kit by week 24'. Statistical analysis will use multivariate logistic regression and will incorporate pairwise comparisons of all three groups, adjusted for multiple testing. ETHICS AND DISSEMINATION: Approvals to conduct the research have been obtained from University College London's Joint Research Office (Ref: 150666), the Screening Research, Innovation and Development Advisory Committee ('RIDAC', Ref: 2223 014 BCSP Kerrison), the Health Research Authority (Ref: 22/WM/0212) and the Confidentiality Advisory Group (Ref: 22/CAG/0140). Results will be conveyed to stakeholders, notably those managing the screening programme and published in peer-reviewed journals/presented at academic conferences. TRIAL REGISTRATION NUMBER: ISRCTN17245519.

Including a general practice endorsement letter with the testing kit in the Bowel Cancer Screening Programme: Results of a cluster randomised trial.

OBJECTIVES: To evaluate the effect of general practitioner endorsement accompanying the screening kit rather than with the invitation letter on participation in the NHS Bowel Cancer Screening Programme and on the socioeconomic gradient in participation in the Programme. METHODS: The NHS Bowel Cancer Screening Programme in England is delivered via five regional hubs. In early 2016, we carried out a cluster-randomised trial, with hub-day of invitation as the randomisation unit. We randomised 150 hub-days of invitation to the intervention group, GP endorsement on the letter accompanying the guaiac faecal occult blood testing kit (75 hub-days, 197,366 individuals) or control, usual letter (75 hub-days, 197,476 individuals). The endpoint was participation, defined as return of a valid kit within 18 weeks of initial invitation. Because of the cluster randomisation, data were analysed by a hierarchical logistic regression, allowing a random effect for date of invitation. Socioeconomic status was represented by the index of multiple deprivation. RESULTS: Participation was 59.4% in the intervention group and 58.7% in the control group, a significant difference (p = 0.04). There was no heterogeneity of the effect of intervention by index of multiple deprivation. We found that there was some confounding between date and screening episode order (first or subsequent screen). This in turn may have induced confounding with age and slightly diluted the result. CONCLUSIONS: General practitioner endorsement induces a modest increase in participation in bowel cancer screening, but does not affect the socioeconomic gradient. When considering cluster randomisation as a research method, careful scrutiny of potential confounding is indicated in advance if possible and in analysis otherwise.

Faecal immunochemical tests for haemoglobin: Analytical challenges and potential solutions.

Quantitative faecal immunochemical tests for haemoglobin (FIT) are being used increasingly around the world in colorectal cancer screening programmes, and in patients presenting with lower bowel symptoms to determine who should proceed to further bowel visualisation investigations, usually colonoscopy. The clinical utility of FIT is well reported. There are a number of analytical challenges including pre-analytical variation, difficulty setting up external quality assessment schemes, access to third party internal quality control material and a lack of standardisation or harmonisation of FIT methods. Here we report the work of the International Federation of Clinical Chemistry FIT Working Group. We provide an overview of the main pre-analytical variables; discuss different approaches to external quality assurance of FIT; propose a solution to third party internal quality assurance materials and summarise the challenges of standardisation and harmonisation of FIT.

Choice of faecal immunochemical test matters: comparison of OC-Sensor and HM-JACKarc, in the assessment of patients at high risk of colorectal cancer.

OBJECTIVES: Currently, NICE recommends the use of faecal immunochemical test (FIT) at faecal haemoglobin concentrations (f-Hb) of 10 µg Hb/g faeces to stratify for colorectal cancer (CRC) risk in symptomatic populations. This f-Hb cut-off is advised across all analysers, despite the fact that a direct comparison of analyser performance, in a clinical setting, has not been performed. METHODS: Two specimen collection devices (OC-Sensor, OC-S; HM-JACKarc, HM-J) were sent to 914 consecutive individuals referred for follow up due to their increased risk of CRC. Agreement of f-Hb around cut-offs of 4, 10 and 150 µg Hb/g faeces and CRC detection rates were assessed. Two OC-S devices were sent to a further 114 individuals, for within test comparisons. RESULTS: A total of 732 (80.1%) individuals correctly completed and returned two different FIT devices, with 38 (5.2%) CRCs detected. Median f-Hb for individuals diagnosed with and without CRC were 258.5 and 1.8 µg Hb/g faeces for OC-S and 318.1 and 1.0 µg Hb/g faeces for HM-J respectively. Correlation of f-Hb results between OC-S/HM-J over the full range was rho=0.74, p<0.001. Using a f-Hb of 4 µg Hb/g faeces for both tests found an agreement of 88.1%, at 10 µg Hb/g faeces 91.7% and at 150 µg Hb/g faeces 96.3%. A total of 114 individuals completed and returned two OC-S devices; correlation across the full range was rho=0.98, p<0.001. CONCLUSIONS: We found large variations in f-Hb when different FIT devices were used, but a smaller variation when the same FIT device was used. Our data suggest that analyser-specific f-Hb cut-offs are applied with regard to clinical decision making, especially at lower f-Hb.

An assessment of the effect of haemoglobin variants on detection by faecal immunochemical tests.

Background Faecal immunochemical tests (FIT) for haemoglobin (Hb) are being used in the investigation of colorectal cancer. These tests use antibodies raised to the globin moiety of human Hb. Where the globin structure is abnormal or reduced, it is possible that antibody binding, and thus Hb-detection may be affected. Methods Lysates prepared from whole blood samples of patients with known variants were diluted in manufacturer-specific buffer to 10, 100 and 500 µg Hb/g faeces. These samples were analysed on four FIT analysers and the results compared with samples with no known variant present (normal samples). Results The results from this study show that of 20 variants tested, three showed a decrease in detection by all four analysers. These were ß-thalassaemia major and two fetal cord blood samples. Conclusions Of 20 common Hb variants studied, 17 did not affect detection of Hb by the FIT systems tested. Hb variants leading to a reduction in the presence of a globin chain caused a reduction in Hb detection; in such cases, cancers could be missed.

Text-message Reminders in Colorectal Cancer Screening (TRICCS): a randomised controlled trial.

BACKGROUND: We investigated the effectiveness of a text-message reminder to improve uptake of the English Bowel Cancer Screening programme in London. METHODS: We performed a randomised controlled trial across 141 general practices in London. Eight thousand two hundred sixty-nine screening-eligible adults (aged 60-74 years) were randomised in a 1 : 1 ratio to receive either a text-message reminder (n=4134) or no text-message reminder (n=4135) if they had not returned their faecal occult blood test kit within 8 weeks of initial invitation. The primary outcome was the proportion of adults returning a test kit at the end of an 18-week screening episode (intention-to-treat analysis). A subgroup analysis was conducted for individuals receiving an invitation for the first time. RESULTS: Uptake was 39.9% in the control group and 40.5% in the intervention group. Uptake did not differ significantly between groups for the whole study population of older adults (adjusted odds ratio (OR) 1.03, 95% confidence interval (CI) 0.94-1.12; P=0.56) but did vary between the groups for first-time invitees (uptake was 34.9% in the control and 40.5% in the intervention; adjusted OR 1.29, 95% CI 1.04-1.58; P=0.02). CONCLUSIONS: Although text-message reminders did not significantly increase uptake of the overall population, the improvement among first-time invitees is encouraging.

Patient factors associated with non-attendance at colonoscopy after a positive screening faecal occult blood test.

Background Screening participants with abnormal faecal occult blood test results who do not attend further testing are at high risk of colorectal cancer, yet little is known about their reasons for non-attendance. Methods We conducted a medical record review of 170 patients from two English Bowel Cancer Screening Programme centres who had abnormal guaiac faecal occult blood test screening tests between November 2011 and April 2013 but did not undergo colonoscopy. Using information from patient records, we coded and categorized reasons for non-attendance. Results Of the 170 patients, 82 were eligible for review, of whom 66 had at least one recorded reason for lack of colonoscopy follow-up. Reasons fell into seven main categories: (i) other commitments, (ii) unwillingness to have the test, (iii) a feeling that the faecal occult blood test result was a false positive, (iv) another health issue taking priority, (v) failing to complete bowel preparation, (vi) practical barriers (e.g. lack of transport), and (vii) having had or planning colonoscopy elsewhere. The most common single reasons were unwillingness to have a colonoscopy and being away. Conclusions We identify a range of apparent reasons for colonoscopy non-attendance after a positive faecal occult blood test screening. Education regarding the interpretation of guaiac faecal occult blood test findings, offer of alternative confirmatory test options, and flexibility in the timing or location of subsequent testing might decrease non-attendance of diagnostic testing following positive faecal occult blood test.

Text Reminders in Colorectal Cancer Screening (TRICCS): Protocol for a randomised controlled trial.

BACKGROUND: Screening with the guaiac faecal occult blood test (gFOBt) is associated with improved colorectal cancer (CRC) survival, and is offered biennially to men and women aged 60-74 years in England's national Bowel Cancer Screening Programme (BCSP). Uptake of the gFOBt is low, with only 54 % of the eligible population completing the test. Text-message reminders could improve uptake of gFOBt. METHODS/DESIGN: This paper describes the protocol for a randomised controlled trial, which will examine the effectiveness of a text-message reminder to promote uptake of gFOBt screening in the BCSP. Individual mobile telephone data from 180 general practices in London with existing mobile-health services will be linked to the national BCSP information system via a secure on-line network. All screening-eligible adults registered with a participating practice will be randomised, to receive either usual care (N = 1600) or usual care plus a text-message reminder to self-complete and return their kit eight weeks after their initial invitation (N = 1600). The primary outcome will be the proportion of individuals who return an adequately completed gFOBt kit within 18 weeks of the initial invitation. Differences in uptake between groups will be evaluated using a logistic regression analysis, adjusting for individual-level and area-level socio-demographic variables. DISCUSSION: This will be the first large-scale randomised trial of a text-message reminder in a national screening programme for CRC. If effective, this study provides a cost-effective means to promote uptake of CRC screening in an organised programme. TRIAL REGISTRATION: Current Controlled Trials ISRCTN70904476 (18/09/2015).

Evidence for dimer formation by an amphiphilic heptapeptide that mediates chloride and carboxyfluorescein release from liposomes.

Heptapeptides having dioctadecyl, N-terminal hydrocarbon chains insert in phospholipid bilayer membranes and form pores through which at least chloride ions pass. Although amphiphilic, these compounds do not typically form vesicles themselves. They insert in the bilayers of phospholipid vesicles and mediate the release of carboxyfluorescein. Hill analysis indicates that at least two molecules of the amphiphile are involved in pore formation. In CD2Cl2, dimer formation is detected by NMR chemical shift changes. The anion release activity of individual anion transporters is increased by linking them covalently at the C-terminus or, even more, by linking them at the N-terminus. Evidence is presented that either linked molecule releases chloride from liposomes more effectively and rapidly than the individual transporter molecule at a comparable concentration.

Anion Transport in Liposomes Responds to Variations in the Anchor Chains and the Fourth Amino Acid of Heptapeptide Ion Channels.

Seven heptapeptide derivatives have been prepared. The peptide structure is (Gly)(3)Xxx(Gly)(3) in which Xxx stands for a variable amino acid. The amino acid variations include azetidine carboxylic acid, pipecolic acid, meta-aminobenzoic acid, proline, and leucine. All seven compounds have a C-terminal benzyl group. In all cases, the heptapeptide's N-terminus was linked to diglycolic acid and a dialkylamine. In five cases, the N-terminal group was didecylamine and in two cases, N-ethyl-N-decyl. Chloride and carboxyfluorescein release from phospholipid vesicles was studied with the result that C(10)H(21)N(C(2)H(5)) COCH(2)OCH(2)CO-NH-(Gly)(3)Leu(Gly)(3)-OCH(2)Ph was the most active. Hill analysis showed that this compound involves pore formation by four monomer units rather than two, as previously found for other members of this family.

The C- and N-Terminal Residues of Synthetic Heptapeptide Ion Channels Influence Transport Efficacy Through Phospholipid Bilayers.

The synthetic peptide, R(2)N-COCH(2)OCH(2)CO-Gly-Gly-Gly-Pro-Gly-Gly-Gly-OR', was shown to be selective for Cl(-) over K(+) when R is n-octadecyl and R' is benzyl. Nineteen heptapeptides have now been prepared in which the N-terminal and C-terminal residues have been varied. All of the N-terminal residues are dialkyl but the C-terminal chains are esters, 2 degrees amides, or 3 degrees amides. The compounds having varied N-terminal anchors and C-terminal benzyl groups are as follows: 1, R = n-propyl; 2, R = n-hexyl; 3, R = n-octyl; 4, R = n-decyl; 5, R = n-dodecyl; 6, R = n-tetradecyl; 7, R = n-hexadecyl; 8, R = n-octadecyl. Compounds 9-19 have R = n-octadecyl and C-terminal residues as follows: 9, OR' = OCH(2)CH(3); 10, OR' = OCH(CH(3))(2); 11, OR' = O(CH(2))(6)CH(3); 12, OR' = OCH(2)-c-C(6)H(11); 13, OR' = O(CH(2))(9)CH(3); 14, OR' = O (CH(2))(17)CH(3); 15, NR'(2) = N[(CH(2))(6)CH(3)](2); 16, NHR' = NH(CH(2))(9)CH(3); 17, NR'(2) = N[(CH(2))(9)CH(3)](2); 18, NHR' = NH(CH(2))(17)CH(3); 19, NR'(2) = N[(CH(2))(17)CH(3)](2). The highest anion transport activities were observed as follows. For the benzyl esters whose N-terminal residues were varied, i.e.1-8, compound 3 was most active. For the C(18) anchored esters 10-14, n-heptyl ester 11 was most active. For the C(18) anchored, C-terminal amides 15-19, di-n-decylamide 17 was most active. It was concluded that both the C- and N-terminal anchors were important for channel function in the bilayer but that activity was lost unless only one of the two anchoring groups was dominant.

Pore formation in and enlargement of phospholipid liposomes by synthetic models of ceramides and sphingomyelin.

A family of compounds having twin octadecyl anchor chains and various polar headgroups were designed to be ceramide mimics. The compounds prepared increase the apparent permeability of phospholipid vesicles to chloride and carboxyfluorescein anions. In addition, significantly larger vesicles are observed after exposure to these compounds suggesting the possibility of vesicular fusion.

The C-terminal ester of membrane anchored peptide ion channels affects anion transport.

Five heptapeptide derivatives, [CH3(CH2)17]2NCOCH2OCH2CO-Gly-Gly-Gly-Pro-Gly-Gly-Gly-OR, in which R = ethyl, 2-propyl, heptyl, benzyl, and cyclohexylmethyl, were found to transport chloride anion through a phospholipid bilayer to varying extents dependent on the identity of R. It was concluded that the R group is a membrane anchor for the synthetic chloride channels.

Anchor chain length alters the apparent mechanism of chloride channel function in SCMTR derivatives.

Two membrane-anchored heptapeptides have been prepared and their pore-formation behavior in phospholipid bilayer membranes has been found to differ profoundly as a result only of alkyl chain length.