Introduction
Early screening for CVD and diabetes risk factors theoretically lowers illness and complication risks, but large real-world trials proving the value of general health checks remain scarce.
The UK launched the NHS Health Check in 2009 for adults aged 40–74, followed by Denmark’s Randers municipality rolling out its “Check Your Health Preventive Programme (CHPP)” in 2012 for 30–49-year-olds, collaborating with local general practitioners (GPs) and municipal health centres.
Major challenges for such mass screening schemes include low uptake and unequal participation: socioeconomically disadvantaged groups consistently skip screenings more often. This trial aimed to test whether CHPP improved CVD risk, physical activity, self-reported health and daily functional ability under routine clinical conditions.
Methods
Study Design & Participants
This pragmatic RCT followed CONSORT guidelines for pragmatic trials. All 30–49-year-old residents of Randers (2012 population: ~95,756) received screening invitations. A core analytic sample of 10,505 citizens was randomly split at household level to avoid cross-contamination between cohabitants, balanced across 38 local GP clinics to distribute workload evenly.
Intervention Components
Each health check package contained four parts:
- GP-sent mailed invitation with pre-booked exam times
- Full physical exam + online lifestyle questionnaire
- Physical tests: height, weight, waist circumference, BMI, blood pressure, blood glucose/cholesterol, lung function, submaximal cycling fitness test
- Surveys: physical activity, smoking, alcohol use (AUDIT), physical and mental self-health
- Instant personalised risk summary report shared with participants and their GPs
- Tiered follow-up support based on disease risk:
- Low risk: maintain healthy lifestyle advice
- Moderate risk: municipal health centre lifestyle coaching (weight, diet, smoking, alcohol, mental health)
- High risk: direct referral to personal GP
Outcome Measurements
- CVD risk: European HeartSCORE 10-year fatal cardiovascular risk
- Behavioural indicators: weekly days of ≥30-min moderate exercise; cycling test cardiorespiratory fitness
- Subjective health: SF-12 physical health rating and SF-12 mental component score
- Labour function: average full-time employment share; number of ≥3-week sick leave spells (from national social registry data)
Statistical Analysis
All analyses accounted for household clustering. Multiple imputation filled minor missing data, and propensity score matching corrected bias caused by uneven participation rates. Linear regression with robust variance estimation generated mean group differences and 95% confidence intervals; p<0.05 marked statistical significance. Sub-analyses tracked GP consultation frequency before and after screening.
Results
- Baseline demographics: IG and CG had identical socioeconomic profiles at randomisation, with an average age of 40.5 years; 51% male participants, 7.4% immigrant backgrounds, 20.5% with under 10 years of formal education.
- Participation patterns: Healthy, higher-income, older non-smokers were most likely to attend both screening rounds; smokers and self-employed residents had the lowest follow-up attendance.
- Primary outcomes: Both raw unadjusted data and adjusted imputed/matched datasets showed no statistically significant gaps between IG and CG on all pre-set health and functional endpoints.
- Healthcare usage: IG participants visited GPs slightly more frequently after health checks, yet the clinical content of these extra consultations was not recorded.
Discussion
Key Strengths
The trial mirrored routine public healthcare rather than artificial research settings, partnering municipal governments, GPs and academic researchers. The full local age cohort was recruited (99.8% coverage), and advanced statistical methods offset biases from low attendance and high dropout. Results apply broadly to European regions with universal tax-funded healthcare and similar middle-low socioeconomic populations.
Limitations
- Effect dilution: Municipal media coverage of the programme likely raised health awareness among control group residents, narrowing outcome differences. Disadvantaged populations were far less likely to join screenings, weakening measurable intervention effects.
- Unknown intervention dosage: No records tracked how many moderate-risk participants completed full municipal lifestyle coaching after screening. GPs faced barriers to referring patients to behaviour change programmes.
- Individual-only focus: The programme targeted personal lifestyle without broader community structural public health interventions, which may limit population-level impact.
Interpretation of Findings
The study population had clear room for health improvement: most failed national physical activity guidelines, 62% were overweight or obese, and 19% smoked daily. Even so, repeated general population health checks failed to shift CVD risk, activity levels or self-reported wellbeing.
These null results align with multiple systematic reviews and large RCTs of universal adult health screening. Universal screening disproportionately attracts already healthier, wealthier participants, widening health inequities—high-risk groups skip follow-up support most often. Targeted screening for high-risk subgroups may deliver greater benefits, a direction for future research.
Conclusion
Mass universal preventive health checks for adults aged 30–49 produced no population-wide improvements in cardiovascular risk, lifestyle behaviour, self-rated health or work capacity. Screening uptake skews toward socioeconomically advantaged, low-risk residents, while vulnerable high-risk groups rarely engage with follow-up support. Future research should design recruitment strategies to boost participation among at-risk populations and test multi-level community-wide prevention models beyond individual clinical screenings.
