Colorectal cancer (CRC) is the fourth most common cancer in the UK and second leading cause of cancer-related deaths. The faecal immunochemical test (FIT) is a non-invasive home-based test used for both symptomatic assessment and population-based screening. However, approximately 30% of screening FIT kits and 10% of symptomatic FIT kits are never returned. Under-served populations, including ethnic minorities, socioeconomically deprived communities and those with mental health conditions, experience particularly low FIT return rates, contributing to health inequalities in CRC outcomes. This systematic review aims to synthesise evidence on the effectiveness and acceptability of interventions to improve FIT returns in both asymptomatic screening and symptomatic populations, with particular focus on under-served communities.

We will conduct a systematic review of qualitative and quantitative evidence. We will search Scopus, MedLine via Ovid, CINAHL via Ebsco and Cochrane Central Register of Controlled Trials from September 2010 onwards, supplemented by reference screening and trial registry searches. Eligible studies will include randomised controlled trials, quasi-experimental studies, observational studies, qualitative studies, mixed-methods studies and implementation studies examining FIT interventions in screening or symptomatic populations. Two reviewers will independently screen search results for eligible studies. Data extraction will capture study characteristics, population demographics, intervention components and outcomes including FIT return rates, acceptability, feasibility and implementation factors. Quantitative data will undergo systematic tabulation and meta-analysis where appropriate, with narrative synthesis for heterogeneous studies. Qualitative data will be analysed using framework-based thematic analysis, mapping findings to both the theoretical domains framework and theoretical framework of acceptability. A mixed-methods synthesis will integrate quantitative and qualitative findings to identify intervention characteristics, implementation strategies and contextual factors associated with improved outcomes across different population groups.

Ethics approval is not required as this systematic review will analyse published studies. Findings will be disseminated through peer-reviewed publication and conference presentations.

CRD420251111663.

Hypertension is the leading risk factor for death globally. Undiagnosed hypertension is common, but the incidence in hospitalised patients is unclear. There are calls for universal facility-based screening for hypertension among all attending patients. The hospital inpatient setting, where blood pressure (BP) is measured routinely and repeatedly, presents an ideal opportunity. However, international hypertension guidelines do not include inpatient BP thresholds for diagnostic or treatment purposes. We investigated the performance of current UK community BP thresholds for diagnosing hypertension in the hospital setting.

Investigate the diagnostic performance of the current UK ambulatory BP diagnostic thresholds for systolic and diastolic hypertension in the hospital setting against the reference test of community-based ambulatory BP monitoring (ABPM).

A prospective diagnostic accuracy study.

Hospital inpatients admitted to three UK centres were approached. Follow-up ABPM was delivered in the community.

Eligible patients were aged between 18 and 80 years, with no prior diagnosis of, or prescription for hypertension, and whose mean cumulative daytime BP was 120 mm Hg to 179 mm Hg systolic and ≤109 mm Hg diastolic from the 24th hour of their hospital admission.

Participants received 24-hour ABPM 4–26 weeks post-discharge, as the reference test for hypertension, with UK diagnostic thresholds of an average daytime BP of ≥135 mm Hg systolic and ≥85 mm Hg diastolic applied. Participants found to be severely hypertensive at the ABPM fitting appointment were also considered reference-test positive but did not proceed with ABPM.

The diagnostic performance of a mean daytime in-hospital BP of ≥135 mm Hg systolic or ≥85 mm Hg diastolic (index test) for the prediction of hypertension diagnosed on ABPM (reference test) was assessed using sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) as primary outcome measures. Additionally, we explored the accuracy of a range of alternative in-hospital systolic and diastolic BP thresholds against the same reference test.

351 participants were enrolled and 206 completed the study protocol. The average age of the 206 participants was 53 years, 55% were male, and 91 (44%) had daytime community hypertension on ABPM reference testing. Of 107 participants with raised in-hospital daytime BP, 59 (55%) had daytime community hypertension. When assessing the performance of the index test for detecting daytime community hypertension, sensitivity was 65% (59/91, 54% to 75%) and specificity was 58% (67/115, 49% to 67%). The PPV was 55% (59/107, 45% to 65%) and NPV was 68% (67/99, 58% to 77%), respectively. A further 45/206 participants (23%) had night-time community hypertension when assessed using European diagnostic thresholds for nocturnal hypertension (120 mm Hg systolic or 70 mm Hg diastolic), while 25/107 of those with raised in-hospital daytime BP (23%) had night-time community hypertension. When assessing the performance of the index test for detecting either day or night-time community hypertension, sensitivity was 62% (84/135, 53% to 70%) and specificity was 68% (48/71, 55% to 78%). The PPV was 79% (84/107, 70% to 86%) and NPV was 48% (48/99, 38% to 59%).

Undiagnosed hypertension is common in hospitalised patients, particularly those with raised in-hospital BP. While in-hospital BP alone is an imperfect predictor and should not be used as a stand-alone diagnostic test, this could serve as a trigger for further assessment of BP in the community after discharge.

The study protocol was registered with the ISCTRN Registry (ISRCTN80586284).