Primary analysis of the timeframe and planning tool (TEMPO), 2 × 4 factorial, randomised controlled study shows that including a deadline of 2 weeks for faecal immunochemical test (FIT) return in the invitation letter resulted in more rapid FIT returns, fewer reminder letters sent, and marginally higher return rates at 3 months, compared with the standard invitation in a nationwide colorectal screening trial embedded in the Scottish Bowel Screening Programme. The planning tool had no positive effect on FIT return.
A deadline for FIT return is a highly cost-effective intervention that could be easily implemented in routine practice through adding a single sentence to the invitation letter, increasing screening uptake and preventing colorectal cancer deaths according to Prof. Kathryn A Robb of the School of Health and Wellbeing, University of Glasgow in Glasgow, UK and colleagues, who published the findings on 12 March 2025 in The Lancet.
The authors wrote in the background that a major challenge for colorectal cancer screening worldwide is achieving high uptake. Across European countries using FIT screening, uptake is around 50%. In Scotland, current uptake is 66% and considerable inequalities in uptake by socioeconomic characteristics exist. Understanding screening behaviour and identifying precise targets for interventions are key to increasing uptake.
TEMPO evaluated the impact of two evidence-based, theory-informed, and co-designed behavioural interventions on uptake of FIT colorectal cancer screening. It is the first trial in the world to evaluate the effect in a nationwide, population-based screening programme of: (1) a suggested FIT return deadline; (2) a problem-solving planning tool; (3) the combination of a deadline and planning tool; and (4) the length of the deadline (1, 2, or 4 weeks) on FIT return. Service users' acceptability of both interventions was also assessed to inform implementation if the interventions were effective.
It was a 2 × 4 factorial, eight-arm, randomised controlled trial embedded in the nationwide Scottish Bowel Screening Programme. All 40000 consecutive adults, aged 50-74 years, eligible for colorectal cancer screening were allocated to one of eight groups using block randomisation: 1. standard invitation; 2. 1-week suggested FIT return deadline; 3. 2-week deadline; 4. 4-week deadline; 5. problem-solving planning tool (no deadline); 6. planning tool plus 1-week deadline; 7. planning tool plus 2-week deadline; 8. planning tool plus 4-week deadline.
The primary outcome was the proportion of FITs returned correctly completed to be tested by the colorectal screening laboratory providing a positive or negative result, within 3 months of the FIT being mailed to a person.
From 19 June to 3 July 2022, 5000 participants were randomly assigned per group, with no loss to follow-up and 266 participants met the exclusion criteria. From a total of 39734 participants included in the analysis, 19909 (50.1%) were female and 19825 (49.9%) were male, mean age was 61.2 years. The control group (no deadline, and no planning tool) had a 3-month FIT return rate of 66.0% (3275 of 4965). The highest return rate of 68.0% was seen with a 2-week deadline without the planning tool (3376 of 4964; difference versus control of 2.0%, 95% confidence interval [CI] 0.2 to 3.9). The lowest return rate of 63.2% was seen when the planning tool was given without a deadline (3134 of 4958; difference versus control of -2·8%, 95% CI -4.7 to -0.8).
The primary analysis, assuming independent effects of the two interventions, suggested a clear positive effect of giving a deadline (adjusted odds ratio [aOR] 1.13, 95% CI 1.08 to 1.19] p < 0.0001), and no effect for use of a planning tool (aOR 0.98, 95% CI 0.94 to 1.02; p = 0.34), though this was complicated by an interaction between the two interventions (pinteraction = 0.0041); among those who were given a deadline, there was no evidence that receiving a planning tool had any effect (aOR 1.02, 95% CI 0.97 to 1.07; p = 0.53), but in the absence of a deadline, giving the planning tool appeared detrimental (aOR 0.88, 95% CI 0.81 to 0.96; p = 0·0030).
In the absence of the planning tool, there was little evidence that the use of a deadline had any effect on return rates at 3 months. However, secondary analyses indicated that the use of deadlines boosted earlier return rates within 1, 2, and 4 weeks, particularly around the time of the deadline, and reduced the need to issue a reminder letter after 6 weeks, with no evidence that the planning tool had any positive impact, and without evidence of interactions between interventions.
This is the first study to assess the effectiveness of providing a deadline for FIT return to increase uptake relative to a standard open invitation in a population-based national screening programme. The absolute increase in uptake with the deadline was modest (1.8-2.0%) but at a population level this could represent 39000 additional participants and 23 colorectal cancer deaths avoided within a 2-year screening round in the Scottish Bowel Screening Programme.
In an accompanied comment, Drs. Hermann Brenner and Michael Hoffmeister of the Division of Clinical Epidemiology and Aging Research, German Cancer Research Center in Heidelberg, Germany wrote that even though the observed increase in adherence was modest, the almost no cost inclusion of a return deadline would be expected to have a substantial public health impact in a population-wide colorectal cancer screening programme, making such an inclusion an exceptionally cost-effective easy to implement intervention.
Given the widespread and increasing implementation of FIT-based colorectal cancer screening programmes in many countries, these results are of high relevance on a global scale. Extra resources needed for the TEMPO trial must have been exceptionally low, ensuring sufficient sample size and power was not an issue, and results are immediately transferrable and translationable.
Using the same or similar methodological approaches, evaluation of further avenues to enhance use of effective cancer screening programmes should be encouraged and promoted. Such avenues might include, for example, further optimisation of invitation materials and logistics, novel approaches to better reach more deprived and typically less adherent population groups, or novel approaches of risk-adapted screening strategies according to the commentators.
The study was funded through grants from the Scottish Government and Cancer Research UK.
References
- Robb KA, Young B, Murphy MK, et al. Behavioural interventions to increase uptake of FIT colorectal screening in Scotland (TEMPO): a nationwide, eight-arm, factorial, randomised controlled trial. The Lancet; Published online 12 March 2025. DOI: https://doi.org/10.1016/S0140-6736(24)02813-7
- Brenner H, Hoffmeister M. Cost-effective improvement of real-world cancer screening. The Lancet; Published online 12 March 2025. DOI: https://doi.org/10.1016/S0140-6736(25)00108-4