Effects of invitation to participate in health surveys on the incidence of cardiovascular disease: a randomized general population study

The feasibility and outcome of a community-based primary prevention program for cardiovascular disease in the 21st century

OBJECTIVE

There is no evidence that systematic screening and risk factor modification in an unselected, asymptomatic population will reduce cardiovascular disease (CVD) mortality. This study aimed to evaluate the effectiveness of a primary care CVD prevention program on mortality during a 13-year follow-up.

DESIGN

A risk factor survey was sent, followed by a nurse-led lifestyle counselling to respondents with at least one CVD risk factor, and a general practitioner's (GP) appointment for high-risk persons. Screening and interventions were performed during 2005-2006.

SETTING

A public health care centre in the town of Harjavalta, Finland.

SUBJECTS

All home-dwelling 45-70-year old inhabitants without manifested CVD or diabetes.

MAIN OUTCOME MEASURES

All-cause and CVD mortality.

RESULTS

Altogether 74% (2121/2856) inhabitants responded to the invitation. The intervention was received by 1465 individuals (52% of the invited population): 398 risk persons had an appointment with a nurse, followed by an appointment with a GP for 1067 high-risk persons. During the follow-up, 370 persons died. Mortality among the non-respondents was twofold compared to the participants'. In subjects who received the intervention, the age- and gender-adjusted hazard ratio for all-cause mortality was 0.44 (95% CI: 0.36 to 0.54) compared to the subjects who did not receive the intervention.

CONCLUSIONS

Reducing mortality is possible in a primary care setting by raising health awareness in the community with screening, by targeted lifestyle counselling and evidence-based preventive medication for persons at high risk for CVD. Subjects not willing to participate in health surveys have the worst prognosis.Key PointsPreviously, there is no evidence that systematic screening and risk factor modification in an unselected, asymptomatic population will reduce cardiovascular disease (CVD) mortality.With a stepwise screening program it is possible to scale the magnitude of CVD prevention in the community.Reducing mortality in a community is possible by screening, targeted lifestyle counselling, and by evidence-based preventive medication for high-risk persons.Subjects not willing to participate in health surveys have the worst prognosis.

General health checks in adults for reducing morbidity and mortality from disease

BACKGROUND

General health checks are common elements of health care in some countries. They aim to detect disease and risk factors for disease with the purpose of reducing morbidity and mortality. Most of the commonly used individual screening tests offered in general health checks have been incompletely studied. Also, screening leads to increased use of diagnostic and therapeutic interventions, which can be harmful as well as beneficial. It is therefore important to assess whether general health checks do more good than harm. This is the first update of the review published in 2012.

OBJECTIVES

To quantify the benefits and harms of general health checks.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, two other databases and two trials registers on 31 January 2018. Two review authors independently screened titles and abstracts, assessed papers for eligibility and read reference lists. One review author used citation tracking (Web of Knowledge) and asked trial authors about additional studies.

SELECTION CRITERIA

We included randomised trials comparing health checks with no health checks in adults unselected for disease or risk factors. We did not include geriatric trials. We defined health checks as screening for more than one disease or risk factor in more than one organ system.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed the risk of bias in the trials. We contacted trial authors for additional outcomes or trial details when necessary. When possible, we analysed the results with a random-effects model meta-analysis; otherwise, we did a narrative synthesis.

MAIN RESULTS

We included 17 trials, 15 of which reported outcome data (251,891 participants). Risk of bias was generally low for our primary outcomes. Health checks have little or no effect on total mortality (risk ratio (RR) 1.00, 95% confidence interval (CI) 0.97 to 1.03; 11 trials; 233,298 participants and 21,535 deaths; high-certainty evidence, I² = 0%), or cancer mortality (RR 1.01, 95% CI 0.92 to 1.12; 8 trials; 139,290 participants and 3663 deaths; high-certainty evidence, I² = 33%), and probably have little or no effect on cardiovascular mortality (RR 1.05, 95% CI 0.94 to 1.16; 9 trials; 170,227 participants and 6237 deaths; moderate-certainty evidence; I² = 65%). Health checks have little or no effect on fatal and non-fatal ischaemic heart disease (RR 0.98, 95% CI 0.94 to 1.03; 4 trials; 164,881 persons, 10,325 events; high-certainty evidence; I² = 11%), and probably have little or no effect on fatal and non-fatal stroke (RR 1.05 95% CI 0.95 to 1.17; 3 trials; 107,421 persons, 4543 events; moderate-certainty evidence, I² = 53%).

AUTHORS' CONCLUSIONS

General health checks are unlikely to be beneficial.

A randomized general population study of the effects of repeated health checks on incident diabetes

BACKGROUND

It is not clear whether offering health checks to the general population can be used to prevent diabetes. Few randomized studies have had a long-term follow-up. We used a randomly selected population cohort as a randomized trial to examine the effect of repeated health checks on the 30-year incidence of diabetes.

METHODS

The study included all persons from 11 municipalities in Copenhagen aged 30, 40, 50, and 60 years (n = 17845). An age-stratified and gender-stratified random sample (N = 4789) was invited to participate in a maximum of three health checks between 1982 and 1994 ('intervention group'). The remaining 12994 persons were defined as the 'control group'. The health checks included a questionnaire, a physical examination including assessment of overweight and blood pressure, and blood sampling with determination of serum lipid levels. Based on the person's answers and test results, the participants were given individual information about the results, disease risk and lifestyle. Their general practitioner, too, was provided with written information on the test results. Both groups were followed in the Danish Civil Registration System, the Danish National Diabetes Register, the Cause of Death Registry, and the National Patient Registry until 31 December 2012.

FINDINGS

There were 2636 incident cases of diabetes and a mean follow-up time of 24.1 years. The age-adjusted and gender-adjusted hazard ratio (HR) (95% confidence interval, CI) for the intervention group versus the control group was HR = 1.07 (95% CI: 0.98, 1.16, p = 0.153).

INTERPRETATION

Offering repeated general health checks to the general population had no preventive effect on the development of diabetes during 30 years of follow-up.

Do high participation rates improve effects of population-based general health checks?

The aim is to investigate if the effect of a health check differs between areas with different participation rates. The Inter99 population-based randomized lifestyle intervention study covered 73 areas within the suburbs of Copenhagen, Denmark. Adults aged 30-60years were randomly drawn from a population and were randomized to intervention group (n=11,483) or control group (n=47,122). Participation rates in the health check varied considerably between areas (mean 52%; range 35-85%). In separate survival analyses, area participation rate was included both as a continuous exposure variable and as a categorical variable (tertiles; low: 35-49%, meddle: 50-54%, high: 55-84%). All persons in the intervention and control group were followed in registers for 10-year total mortality and combined events (ischemic heart disease, stroke, or both). In adjusted models (including sociodemographic variables, ethnicity, number of children and comorbidity), among men, there was no difference in risk of death between areas with varying participation rates. Surprisingly, among women living in high-participation areas a significantly higher risk of all-cause mortality (HR: 1.32 [1.03-1.69]) was found in the intervention group (ref=controls). For both men and women, in no areas there was any difference between intervention and control group in incident IHD/stroke. Higher participation rates in population based health checks is probably unlikely to improve the effects of these, and may in worst case be harmful in subgroups of the population. Further well-designed studies within non-participation research should have high priority and are required to establish link between health checks and risk of death in subgroups of the population.