Effectiveness of a web-based health risk assessment with individually-tailored feedback on lifestyle behaviour: study protocol
BMC Public Health
Effectiveness of a web-based health risk assessment with individually-tailored feedback on lifestyle behaviour: study protocol
Eva K Laan 0 2
Roderik A Kraaijenhagen 2
Niels Peek 1
Wim B Busschers 0
Marije Deutekom 0
Patrick M Bossuyt 3
Karien Stronks 0
Marie-Louise Essink-Bot 0
0 Department of Public Health, Academic Medical Center , Amsterdam , The Netherlands
1 Department of Medical Informatics, Academic Medical Center , Amsterdam , The Netherlands
2 NDDO Institute for Prevention and Early Diagnostics (NIPED) , Amsterdam , The Netherlands
3 Department of Clinical Epidemiology , Biostatistics and Bioinformatics (KEBB) , Academic Medical Center , Amsterdam , The Netherlands
Background: Physical inactivity, unhealthy dietary habits, smoking and high alcohol consumption are recognized risk factors for cardiovascular disease and cancer. Web-based health risk assessments with tailored feedback seem promising in promoting a healthy lifestyle. This study evaluates the effectiveness of a web-based health risk assessment with individually-tailored feedback on lifestyle behaviour, conducted in a worksite setting. Methods/Design: The web-based health risk assessment starts with a questionnaire covering socio-demographic variables, family and personal medical history, lifestyle behaviour and psychological variables. Prognostic models are used to estimate individual cardiovascular risks. In case of high risk further biometric and laboratory evaluation is advised. All participants receive individually-tailored feedback on their responses to the health risk assessment questionnaire. The study uses a quasi-experimental design with a waiting list control group. Data are collected at baseline (T0) and after six months (T1). Within each company, clusters of employees are allocated to either the intervention or the control group. Primary outcome is lifestyle behaviour, expressed as the sum of five indicators namely physical activity, nutrition, smoking behaviour, alcohol consumption, and symptoms of burnout. Multilevel regression analysis will be used to answer the main research question and to correct for clustering effects. Baseline differences between the intervention and control group in the distribution of characteristics with a potential effect on lifestyle change will be taken into account in further analyses using propensity scores. Discussion: This study will increase insight into the effectiveness of health risk assessments with tailored feedback and into conditions that may modify the effectiveness. This information can be used to design effective interventions for lifestyle behaviour change among employees. Trial registration: Dutch Trial Register NTR8148.
Ehealth; Lifestyle behaviour; Health risk assessment; Worksite health promotion
Most people in western European populations do not
meet current recommendations for healthy behaviour, in
terms of sufficient physical activity, healthy dietary habits,
limited alcohol consumption and non-smoking . For
example, in 2008, 37% of European adults aged 15
years was insufficiently active, i.e. less then 150 min of
moderate physical activity per week and the prevalence
of daily tobacco smoking among this population was
In the Netherlands, in 2007, according to the Dutch
Healthy Physical Activity Guideline (30 min/day, 5 days/
week at moderate intensity level) 41% of the population
aged 18 years was insufficiently active, and 84% was
insufficiently active according to the cardio-respiratory
fitness guideline of 20 min/day, 3 days/week at high intensity
level [2,3]. Results of the Dutch national food
consumption survey in 2003 showed that, among young adults
(1930 years), only 5.5% of men and 0.2% of women consumed
the recommended amount of vegetables (150 g/day) and
only 7-8% consumed the recommended amount of fruit
(200 g/day) . Smoking and drinking are also still
common behaviours. In 2008, 27% of the population aged 15
years was smoking, and 14% of men and 11% of women
aged 12 years were drinking too much alcohol .
Unhealthy behaviour is known to be a risk factor for
chronic conditions such as diabetes, cardiovascular
diseases and cancer . Therefore, promoting healthy
behaviour has become a central goal of public health policy.
Various programs have been developed to promote
healthy behaviour and lifestyle change. Offering health
promotion interventions via the worksite allows reaching
large groups of adults, because most spend a large portion
of their waking hours at their workplace . Health
promotion via the worksite has the additional advantages of
enabling the introduction of social support, and making
use of a natural social network for peer support . Health
promotion via the worksite may also offer opportunities to
make environmental and structural changes that support
healthy behaviour . A healthier lifestyle, with the
prevention of related (chronic) diseases, not only benefits
employees and society, but also employers, in the form of
less sickness absence and lower productivity losses .
The health risk assessment (HRA) is a commonly used
instrument in the promotion of healthy behaviour .
A recent review showed that a HRA is useful as a gateway
intervention to broader worksite health promotion
programs . HRAs screen for risk factors of disease and
provide feedback on those risks. Many HRAs now make
use of the Internet, which allows delivering
individuallytailored interventions . For example, within the
worksite setting, emails and web pages can reach broad and
diverse employee populations . With web-based HRAs,
employees are also able to apply the program in privacy,
e.g. at home, and at a time that suits them . However,
although HRAs are promising, there is limited knowledge
about what actually makes them work .
The primary aim of this study is to evaluate the
effectiveness of a web-based HRA with individually-tailored
feedback conducted in a worksite setting, on lifestyle
behaviour. A secondary aim is to explore conditions that could
modify the effectiveness in specific settings or subgroups.
The results of this study will contribute to the evidence
base for web-based HRAs with tailored feedback aimed at
changing health behaviour.
A quasi-experimental study will be conducted with a
waiting list control group, carried out in a worksite
setting. The study population consists of employees of
companies that embedded the HRA in their corporate health
management strategy. Data are collected at baseline (T0)
and after six months (T1). Data collection started in
April 2011. According to Dutch law, medical ethical
approval of the study was not required, as confirmed by
the Medical Ethics Committee of the Academic Medical
Centre of the University of Amsterdam. All necessary
precautions to protect privacy of subjects were taken.
The intervention is called the Prevention Compass. It
has been developed by the NDDO Institute for
Prevention and Early Diagnostics (NIPED) in Amsterdam. The
Prevention Compass consists of a web-based HRA with
tailored feedback. Participation in the intervention is on a
voluntary basis. All current employees of a participating
company are invited to participate in the intervention.
Excluded are pregnant women or women with a
pregnancy in the past 6 months because, in this group, such
measurements could result in abnormal values.
Invitation for the intervention
Employees are invited through a letter sent to their home
address. An information leaflet with a description of the
intervention is enclosed. The invitation letter informs
employees that participation is voluntary, involves no
personal costs, and that all personal data are treated
confidentially, meaning that no data are shared with their
employer, and that the data are used in an anonymous
form for the present study only. No written informed
consent is obtained, due to the fact that the intervention
is online. Completion of the questionnaire is regarded as
informed consent to participation. The invitation letter
contains an activation code for registration at the
interventions website http://www.preventiekompas.nl. For
each participant, a personal online health portal is made
available. Here participants can fill in the questionnaire,
order a box with measurement tools (see below), and
view their results of the HRA. After registration,
participants receive a personal number for secure access to
their portal. In case of no response to the letter of
invitation, invitees receive a single reminder after three weeks,
in the form of a second letter to their home address.
Web-based health risk assessment
The web-based HRA starts with a questionnaire, covering
socio-demographic variables, family and personal medical
history, lifestyle behaviour (physical activity, smoking
behaviour, alcohol consumption, dietary pattern) and
psychological variables (stress, burnout, depression).
Individual scores are used to estimate cardiovascular
disease risk using validated risk scores. All risk calculations
are based on prevailing practice guidelines, including the
European and Dutch guidelines for cardiovascular risk
management [13,14]. Individuals at increased risk for
cardiovascular disease, diabetes and kidney disease are
advised to perform additional biometric and laboratory
evaluation. For this, participants can order a box with
measurement tools via their portal. This box includes a
sphygmometer, a measuring tape and instruction cards
for measurement of blood pressure and waist
circumference. Participants also receive a lab box with materials to
collect a urine sample for cardio-metabolic
measurements. All participants who ordered the lab box visit a
central facility where urine samples can be handed in,
and a blood sample is taken for analysis of total
cholesterol, LDL-cholesterol, HDL-cholesterol, triglycerides,
glucose, creatinin, urinary albumin to creatinin ratio, and
HbA1C. Results are electronically transferred to the
central HRA database. After additional measurements,
results are used to recalculate the cardio-metabolic risk,
define kidney function using the MRDR formula, i.e. to
estimate the glomerular filtration rate (eGFR) and
albumin-creatinin ratio and detect (pre)diabetes based on
glucose and HbA1C values.
For system security and data protection reasons,
personal identification data and HRA data are stored on
separate servers. An electronic firewall is placed between the
servers and the Internet. Only participants certified by ID
and password are able to access the servers.
Theoretical framework for lifestyle change
The tailored feedback provided as part of the intervention
is based on Prochaskas transtheoretical model .
According to this model, behavioural change is a process
consisting of five subsequent phases: precontemplation
(no intention of behaviour change between one and six
months), contemplation (considering behaviour change
between one and six months), preparation (getting ready
to change behaviour in the next month), action
(performing the change in behaviour), and maintenance (steady
stage of behaviour change reached). In the feedback,
individuals receive a health plan that fits with their current
stage of change. Participants in earlier stages receive
information to motivate them to change their lifestyle and
participants in later stages receive concrete action plans how
to change their lifestyle behaviour.
Participants receive tailored feedback based on their
responses to the HRA questionnaire and additional
measurements if indicated. The feedback contains a health risk
profile divided into four domains: lifestyle, psychological,
social (including work-related aspects) and physical, and
each of these divided into sub-domains (Table 1). For each
of these domains the assessed health risk is explained
using a simple grid labelled by one of three colours: green
representing normal risk, orange representing moderately
elevated risk and red representing seriously elevated risk.
In addition, threats associated with elevated risk (orange
and red categories) and potential gains of taking
preventive action are explained. The feedback concludes with an
overview of actions the participant can take. The number
of possible actions depends on the outcome of the HRA.
All options include suggestions from trusted external
parties, where participants could go for support for the action
they want to take. The suggestions are made to fit with
their expressed preferences, such as for guided vs.
In summary, differentiations are made between the stage
of motivation (see Theoretical framework for lifestyle
change), the preferences for professional guidance (yes/
no), actions in groups or alone, actions outside or close to
home, and actions via internet, telephone or face-to-face.
In case of high risk (red category), the feedback includes
referral for further medical evaluation and treatment if
Study population and procedure
All employees aged 18 years from companies
participating in the study are eligible for participation in the
evaluation study. Individual participation in the study is
on a voluntary basis. Employees in the intervention
group receive an invitation for participation in the HRA
at baseline. Their completion of the lifestyle items in the
questionnaire of the HRA serves two purposes: it belongs
to their HRA but also acts as a baseline measurement of
health behaviour for the evaluation study. Six months
later participants receive an invitation for a short,
electronic lifestyle questionnaire that serves as follow-up
Employees in the control group receive an invitation for
the short, electronic lifestyle questionnaire at baseline. In
this group this questionnaire serves as the baseline
measurement. Six months later control group participants
receive an invitation to take part in the HRA. The
completion of the lifestyle items in the questionnaire of the HRA
now serves as follow-up measurement (Figure 1).
Allocation to the intervention or control group
Individual allocation may lead to contamination between the
groups in the case that collaborating employees are
allocated to different groups; this could then imply that the
results are influenced by factors other than the
intervention. Therefore, we rely on allocation by cluster. Within
each company, clusters of employees with comparable
activities and of comparable size are allocated to either the
intervention or the control group.
Due to practical limitations, random allocation of
clusters to the intervention and control group is not possible.
Both the intervention and the study have to be embedded
in the corporate health management strategy of the
participating companies. Allocation of units to the intervention
and control group will follow the roll-out procedure of the
company, i.e. by geographical region and mainly based on
practical considerations of the company management like
current reorganization. Although the allocation procedure
Table 1 Health-related domains and sub-domains on which participants of the health risk assessment receive tailored
Interaction with colleagues
Body weight and fat distribution
*Only if additional biometric and laboratory evaluation are performed.
is not random, confounding is unlikely; conversations with
the management teams of companies confirm that clusters
could not obtain priority in the allocation procedure.
Furthermore, effects of this limitation on the estimate
of the effect of the intervention will be minimized by
adjusting for baseline characteristics of clusters in the
statistical analysis (see Statistical analysis).
Invitation for the lifestyle questionnaire (control
group) Employees are invited through a letter to their
home address to complete the lifestyle questionnaire via
Internet. An information leaflet about the evaluation study
is enclosed. The invitation letter informs employees that
participation is voluntary, that all personal data are treated
confidentially, and that no result is shared with their
employer and only used in anonymous form for the
present study. The invitation letter contains a unique number
for access to the questionnaire via the website. In case of
no response to the letter of invitation, participants receive
a single reminder after three weeks, in the form of a letter
to their home address.
The responses to the HRA questionnaire are used for two
purposes. First, the responses form the basis for generation
of the tailored feedback. Second, the responses to the
lifestyle items are used to analyse the outcome measures of
this evaluation study.
Primary outcome is lifestyle behaviour, expressed as the
sum of five indicators (physical activity, nutrition,
smoking behaviour, alcohol consumption and symptoms of
burnout). For each indicator, adherence to the Dutch
guidelines (yes/no) is determined. The magnitude of
change in lifestyle behaviour measured after six months
determines whether or not the intervention is successful.
Figure 1 Schematic overview of the participation.
Physical activity Physical activity is measured with two
items derived from the Dutch version of the
International Physical Activity Questionnaire (IPAQ) .
These two closed-ended items provide information on
the frequency (days per week) and duration (minutes)
spent on moderate intensity and vigorous physical
activity in a normal week.
The public health recommendation for physical activity
in the Netherlands, the Dutch Healthy Physical Activity
Guideline (Nederlandse Norm Gezond Bewegen),
recommends physical activity for 30 min (or more) per day at a
moderate or vigorous intensity level, for at least 5 days a
week . Adherence to this guideline is measured with
one additional item about the number of days that the
participant is physically active for 30 min (or more) per
day at a moderate or vigorous intensity level.
To generate the feedback, the total duration of physical
activity in min/week is calculated, collating moderate and
vigorous activities. Additionally, total physical activity
duration is dichotomized into 150 min/week or 150
min/week, as a second way of reflecting adherence to the
Dutch Healthy Physical Activity Guideline.
For the evaluation study, adherence to the
cardiorespiratory fitness guideline (Fitnorm) is also analyzed.
This guideline recommends physical activity for 20 min
(or more)/day at a vigorous intensity level, for at least 3
days/week . Adherence to this norm is analyzed using
the questions described above. Total physical activity
duration is dichotomized into 60 min/week or 60 min/
week. The cardio-respiratory fitness guideline is not used
in the tailored feedback of the intervention.
Nutrition Different aspects of the dietary pattern are
taken into account, as defined by the Dutch Dieticians
Cooperation: fruit and vegetables, saturated fat intake,
intake of sugar, and fish.
Items concerning fruit and vegetables are based on a
standard nutrition questionnaire of the Dutch Municipal
Health Service . Participants are asked to report their
fruit intake in pieces of fruit per day in a normal week.
They also are asked to report the number of serving
spoons of vegetables per day in a normal week. In the
Netherlands, a daily intake of at least 2 pieces of fruit and
200 g of vegetables (4 spoons per day, defining a serving
spoon of vegetables as 50 g) is the public health
Saturated fat intake is measured with items developed in
expert meetings. Participants are asked to report the
amount of snacks, use of butter, cheese and meat
(portions/day), dairy products and sweets. To generate the
feedback each answer has a score that cumulatively leads
to a total score for saturated fat intake. Experts defined a
cut-off value that is used to determine the colour (green/
orange) used in the feedback.
The intake of sugar is based on the amount of teaspoons
of sugar, as well as sweet drinks and sweet snacks
consumed per day. Again, to generate the feedback, each
answer has a score that cumulatively leads to a total score
for intake of sugar; a daily intake of 40 g or less is
Also noted are the frequency of breakfast (days/week)
and the frequency of fish (portions/week). The public
health recommendation of frequency of breakfast is every
day, thus 7 days a week . For fish, this
recommendation includes fish consumption at least two times a week,
of which at least one portion fatty fish . All aspects of
the dietary pattern are dichotomized according to the
guidelines, to generate the feedback.
Smoking behaviour Smoking behaviour is measured by
items from a questionnaire of the Dutch Expert Centre
on Tobacco Control (STIVORO) . To generate the
feedback, participants are categorized into non-smokers,
ex-smokers, incidental smokers, daily smokers and heavy
smokers. A heavy smoker is defined as smoking 10 or
more units of tobacco per day. The evaluation study only
incorporates the questions if the participant is currently
smoking (yes/no), and then the kind of tobacco, and the
units of tobacco per day.
Alcohol consumption Alcohol consumption is measured
in units of alcohol per day based on a standard alcohol
questionnaire of the Dutch Municipal Health Service .
For men and woman different limits for excessive alcohol
consumption are used; for men alcohol consumption up
to 21 units/week and for women alcohol consumption up
to 14 units/week is recommended as maximum.
Furthermore, alcohol dependence is measured using the
fiveshot questionnaire . This questionnaire gives an initial
indication concerning alcohol dependence via 5 questions.
Each answer has a score that contributes to a total score
of alcohol dependence. The total score has a defined
cutoff value for alcohol dependence. To generate the
feedback, the units of alcohol per day and the score of the
five-shot questionnaire are dichotomized according to the
Burnout The UBOS questionnaire is used for symptoms
of burnout ; this questionnaire is the Dutch version
of the the Maslach Burnout Inventory . Each answer
has a score that contributes to a total score of indication
for burnout. The total score has a defined cut-off value.
To generate the feedback, indication for burnout is
dichotomized according to this value.
Determinants of behavioural change
Additional determinants of health behavioural change
are measured, as described below.
Intention to behaviour change The intention to change
behaviour is measured per lifestyle variable. Answer
options are based on the different phases of Prochaskas
Stage of Change model , and are formulated as:
I dont have any intention to change my lifestyle between
one and six months, I am considering to change my
lifestyle within between one and six months, Im getting
ready to change my lifestyle in the next months, Im
already working to improve my lifestyle, and I have
reached the intended lifestyle behaviour and still perform
Self-efficacy Self-efficacy is measured by one newly
developed item where participants have to indicate to what
extent they feel able or unable to change their lifestyle
behaviour if necessary. This item is formulated as: I am
able to change my lifestyle behaviour if necessary.
Answers are rated on a 5-point Likert scale ranging from
1 (totally agree) to 5 (totally disagree).
Social support Social support is measured by three items;
two reflecting the support for participating in a HRA with
tailored feedback from the respondents work environment
(colleagues and managers), and one reflecting the support
from the respondents partner and/or family. Respondents
are asked to complete the statements: According to my
colleagues, participation in a HRA with tailored feedback
is useful, According to my manager, participation in a
HRA with tailored feedback is useful, and According to
my partner and/or family, participation in a HRA with
tailored feedback is useful. Answers are rated on a 5-point
Likert scale ranging from 1 (very useful) to 5 (totally
useless) and an additional answer option I dont know.
Non-random allocation to the intervention and control
group may result in an unequal distribution of the
characteristics of employees and/or companies and their units,
which can influence the changes in lifestyle behaviour.
Measured potential confounders of the change in lifestyle
behaviour include age, gender and educational level, years
of work at the current company, years in current function,
and part-time or fulltime employment.
Descriptive statistics will be used to describe and compare
baseline characteristics of participants and clusters in the
intervention and control group. Any baseline differences
with a potential effect on lifestyle change will be taken
into account in further analyses using propensity score
weighting. To estimate the effect of the intervention on
lifestyle behavioural change logistic regression analysis (for
binary outcome measures) and linear regression analysis
(for continuous outcome measures) will be used. To
correct for a potential clustering effect, multilevel analyses
will be performed. In case the follow-up measurement
result in a considerable amount of missing data, multiple
imputation methods will be used.
The sample size calculation is based on the primary
outcome, lifestyle behaviour, expressed as the sum of five
indicators. We consider a difference in a range of 0.3 to
0.5 points more behavioural change in the intervention
group compared to the control group as a meaningful
effect (power of 80%; one-sided significance level, 0.05).
With an intra-cluster correlation of 0.05 (as in a previous
study among employees ), and an average of 30
employees per cluster (based on 100 eligible employees
per cluster, 30% initial participation), we must include at
least 17 clusters per group, thus a total of 1020 employees,
to find a difference of 0.3 points. To find a difference of
0.5 point we have to include at least 7 clusters per group,
thus a total of 420 employees.
The study presented here is designed to evaluate the
effectiveness of a health risk assessment with tailored feedback
conducted in a worksite setting, on lifestyle behaviour.
The rationale for this study is the wide availability and use
of worksite HRAs, in combination with the lack of
evidence concerning their impact on health behaviour.
Results may be relevant for future development and
implementation of web-based interventions aimed at
improving lifestyle behaviour relevant for prevention of
cardiovascular diseases and cancer. In the present study,
the broad approach of the evaluated HRA, and the fact
that feedback is tailored to participants characteristics,
make it of potential interest for all individuals and not
only for those at high risk. It creates awareness of
unhealthy behaviour before chronic disease symptoms are
present, by providing information about (un)healthy
behaviour in the health recommendations. This is a crucial
step for those not yet ready for behavioural change.
The fact that the present evaluation is performed in a
real-life setting is a strength, because this provides a
realistic estimate of effectiveness. The controlled design allows
for evaluation of the effect, in addition to autonomic
change in lifestyle behaviour.
Potential sources of bias include the Hawthorne effect,
registration bias, and carry-over bias. The Hawthorne
effect can occur in individuals who change their
behaviour due to the attention they receive from, e.g. the
researchers. In this case, however, the effect is probably
limited because the intervention is mostly provided
online with little contact with the researchers. Bias due
to participants giving socially desirable answers is a
possibility when using self-report questionnaires; although we
aim to minimise such bias by formulating the items in a
neutral way and using validated questionnaires where
possible, it cannot be excluded. Finally, we aim to limit
carry-over bias by the use of cluster randomization.
Taking into account the benefits of a worksite setting
and the web-based delivery of the HRA, we believe this
HRA is applicable to and attractive for the population at
large. This study has the potential to make a substantial
contribution to the development of effective
interventions for lifestyle behaviour change among a working
population. Results are expected to be available in 2013.
This study is funded by ZonMw, the Netherlands Organisation for Health
Research and Development. ZonMw project number 200310006.
MD designed and wrote the original proposal, supported by KS, PB and RK.
EL further developed the study protocol and is responsible for data
collection, data analysis, and drafting of the final research report, supervised
by MLE, NP and RK. All authors participated in discussing the design of the
study and developing the research protocol. All authors have read and
approved the final manuscript.
Roderik A Kraaijenhagen is medical director and co-owner of NIPED. This
institute developed and currently markets the studied program in the
Netherlands. NIPED assists several research programs for scientific quality
assurance purposes that are conducted by academic institutions. The
present study is an example of such a project. During this research, Eva K
Laan was employed at NIPED on a part-time basis (4 h/week) for which she
received a salary.
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