Health Promotion International Advance Access originally published online on November 8, 2004
Health Promotion International 2004 19(4):463-470; doi:10.1093/heapro/dah408
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HEALTH PROMOTION INTERNATIONAL Vol. 19. No. 4 © Oxford University Press 2004; All rights reserved.
Acceptability and feasibility of an interactive computer-tailored fat intake intervention in Belgium
1Ghent University, Faculty of Medicine and Health Sciences, Department of Movement and Sport Sciences, Belgium and 2Erasmus Medical Centrum, Department of Public Health, The Netherlands
Address for correspondence: Ilse De Bourdeaudhuij, Watersporttaran, 9000 Gent, Belgium E-mail: Ilse.DeBourdeaudhuij{at}ugent.be
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SUMMARY |
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 TOP SUMMARY INTRODUCTIONMETHODSRESULTSDISCUSSIONREFERENCES |
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In order to reduce the risk of chronic diseases health authorities recommend restricting fat intake to 30% of the total energy uptake. However, fat intake in Belgium is much higher warranting interventions aimed at reducing fat intake. Tailored interventions have shown to be promising; however, studies on effectiveness of interactive computer-tailored systems are needed. We investigated the acceptability and feasibility of a recently developed interactive computer-tailored fat reduction intervention. Differences in the reported acceptability and feasibility according to demographic and stages of change were explored. Participants (n = 220) completed a computerized questionnaire, and received a personal fat intake advice, which was almost immediately displayed on screen. They also completed an evaluation questionnaire, during and after they ran the tailored program, with questions on the quality, user-friendliness and applicability of the program. Participants rated the program positively on all aspects. No significant differences in acceptability and feasibility scores were found according to sex, education levels and computer literacy. Although several significant differences were found between age groups and stages of change (oldest group, contemplators and preparators were more positive about the program), the importance of these differences is probably not great, since acceptability and feasibility scores for the different age groups and stages of change were always very high. These results suggest that the computer-tailored intervention is an acceptable and feasible tool for reducing fat intake in a general population in Belgium.
Key words: dietary fat; pre-testing; tailoring
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INTRODUCTION |
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TOPSUMMARYINTRODUCTIONMETHODSRESULTSDISCUSSIONREFERENCES |
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Evidence from epidemiological, clinical and experimental data demonstrates that diets that are high in saturated fat intake are associated with an increased risk of cardiovascular disease (Kuller, 1997
; Hooper et al., 2001), possibly some cancers (Kuller, 1997), obesity (Satia-Abouta et al., 2002), diabetes (Van Dam et al., 2002) and other health problems. In Belgium the dietary guidelines (National Council on Nutrition, 1997) are very similar to the American Heart Association guidelines (Krauss et al., 1996) and recommend eating <30% energy from fat. Food consumption research showed that a small proportion of the Belgian population complies with the fat intake guideline. A mean total fat intake of 41.8 energy% for men and 42.6 energy% for women has been reported (Staessen et al., 1998; De Henauw and De Backer, 1999). There is no evidence that fat intake in Belgium has decreased in recent years (Paulus et al., 2001; De Vriese et al., 2001).
A major difference between dietary fat intake and other behaviour associated with chronic disease, such as smoking, is that individuals are often unaware of their dietary risk behaviour (Brug et al., 1994). In Belgium 74% of the population agree that they do not need to make dietary changes since they perceive their diet to be healthy enough as it is (Kearney et al., 1997). This discrepancy between actual fat intake and awareness of fat intake is consistent with studies conducted in the US and the Netherlands (Brug et al., 1994; Glanz et al., 1997) and is a major barrier in interventions aimed at reducing fat intake. People who perceive their diet in accordance with recommendations are not motivated to change (Brug et al., 1994) and may perceive generic healthy diet promotion messages as not relevant (Kearney et al., 1997). Furthermore healthy diet promotion interventions, that may increase awareness of personal fat intake in order to motivate fat reduction behaviours, are needed in Belgium (Brug et al., 1999; De Bourdeaudhuij et al., 2002).
Evidence shows that computer-tailored nutrition education provides people with personally relevant diet information. Such interventions may also provide people with personally adapted suggestions to change behaviours that are potentially health-threatening and to maintain behaviours that are beneficial for health (De Vries and Brug, 1999; Brug and Van Assema, 2000; Kreuter et al., 2000). Based on systematic reviews of the computer-tailoring literature it has been concluded that computer-tailored nutrition education is superior to generic nutrition education in effects on dietary intake and psychosocial predictors of dietary behaviours. Computer-tailored nutrition interventions are also more likely to be read, remembered and experienced as personally relevant compared with standard materials (Brug et al., 1999; Kreuter et al., 2000).
Despite the fact that computer-tailored nutrition interventions showed promising effects, most of the interventions used to date have been defined as first generation tailored interventions (De Vries and Brug, 1999; Brug and van Assema, 2000). These first generation interventions are characterized by the fact that computer technology is used relatively sparsely. Written questionnaires are used and it often takes several weeks for participants to receive their tailored feedback letter from the research team. This feedback is generated by a computer program and printed in a personal letter format. In second generation interventions, interactive computer programs are used, after answering questions feedback is directly provided on the computer screen (Brug and van Assema, 2000). To date almost no second generation interventions were evaluated nor implemented. One might suggest that these interventions will perform even better since they obviously have several advantages over first generation nutrition education interventions. However, interactive computer-tailored interventions may have some specific drawbacks, which argue for extensive acceptability and feasibility testing before implementation. Interactive computer systems create the illusion of personal interaction, however, in reality everything is computer controlled and there is no one to assist participants or to make adjustments whenever something goes wrong or a computer error appears (Vandelanotte and De Bourdeaudhuij, 2003). Incorrect decision rules or wrong cut-off scores can cause the participants to receive feedback that is not correctly tailored (Kreuter et al., 2000). Likewise, Kreuter et al. (Kreuter et al., 2000) argue that acceptability and feasibility testing of computer-tailored interventions is needed and will be more difficult and complex than acceptability and feasibility testing of non-tailored materials. Acceptability and feasibility testing will also affect comprehensiveness, relevance, credibility, acceptability and attractiveness of the intervention, which are necessary for attitude and behaviour change (Weinreich, 1999). Further, an acceptability and feasibility testing targeted at several subgroups, such as different age, gender, education and stage of change groups, might prevent implementing an intervention that only applies to small subgroups, such as people that are already motivated to change their behaviour or moderate to high social class people.
Fat intake in Belgium is very high; however, no interventions to reduce fat intake of any kind were reported. The need to reduce fat intake in Belgium is great and a thorough approach is desirable. Therefore, the aim of this study is to investigate acceptability and feasibility of a recently developed interactive computer-tailored fat intake intervention in a general population. We wish to test usability, user-friendliness, credibility, feasibility, comprehensibility, readability and related factors. We further explore whether there are differences in the reported feasibility and acceptability of the intervention between individuals of different stages of change, sexes, age groups, education levels and computer literacy.
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METHODS |
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TOPSUMMARYINTRODUCTIONMETHODSRESULTSDISCUSSIONREFERENCES |
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Participants and procedure
A convenience sample of 220 adults was used (Table 1). Participants (between 20 and 60 years) were recruited in and around the city of Ghent (Belgium).
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Each participant received a computer disk containing the interactive computer-tailored fat intervention, an evaluation questionnaire to assess acceptability and feasibility of the intervention, and written instructions on how to use the program. Participants were especially asked to be as critical as possible about the intervention. Participants were free to run the program at their convenient place and time. Participants without a computer could use a portable computer temporarily provided by the research team. Going through the program and questionnaire took about 50–60 minutes. After completion, the research team personally collected the questionnaires and the intervention materials.
Intervention
The fat intake intervention aimed to encourage reduction in fat intake in those participants who did not meet the guidelines on fat intake. An introduction page led participants to a computerized diagnostic tool, which they completed in order to receive the fat intake advice (also called feedback). It consisted of questions about participant demographics, fat intake and psychosocial determinants. The fat intake questions were newly developed. No Flemish alternative to measure fat intake was available. Since dietary habits are geographically bounded it was not possible to use a foreign fat intake questionnaire and preliminary data showed that this self-administered computerized diagnostic tool had a good reliability and adequate validity (Vandelanotte and De Bourdeaudhuij, submitted for publication). The questions about psychosocial determinant were about knowledge, social support, self-efficacy, attitudes, perceived benefits and barriers, intentions and environment.
After the completion of the diagnostic tool, the fat intake feedback was immediately displayed on screen. This feedback was selected from a database filled with messages that match any possible combination of answers and was based on the theory of planned behaviour (Ajzen, 1985) and the Transtheoretical Model (Prochaska et al., 1992). Message content and the way in which the participants were approached differed along the stages (Vandelanotte and De Bourdeaudhuij, 2003).
In practice this implicated that the fat intake advice started with a general introduction, followed by normative feedback, which related participants' fat intake to current recommendation, next (if needed) a part of advice that indicated what fatty foods they consumed and tips on how they could reduce or replace these foods. Finally, the advice ended by giving information on their personal psychosocial determinants of fat intake.
Evaluation questionnaire
Based on existing questionnaires assessing feasibility and acceptability of nutrition interventions in the Netherlands a self-administered evaluation questionnaire assessing usability, user-friendliness, credibility, feasibility, comprehensibility and readability was developed (Brug et al., 2000). The questionnaire consisted of three parts. Part one contained questions about participants' demographics (gender, age, weight, height, work situation, job category, education, residential area) and stages of change. For stages of change two questions were asked (first question, are you planning to eat less fat than you do now? No/yes, within six months/yes, within one month. Second question, in the past six months, did you eat more or less fat? More/as much/less.). Together with participants' level of fat intake (above or under the fat intake recommendation, this information was presented in their fat intake advice and also reported on the evaluation questionnaire) these questions allowed the participants to be grouped into five stages of change (Curry et al., 1992; Greene and Rossi, 1998). In the second part participants could write down suggestions and remarks concerning the computerized intervention. Part three consisted of questions on acceptability and feasibility, that could be answered on five-point Likert scales (1 = I don't agree at all, 5 = I totally agree), about the diagnostic tool: I think the diagnostic questions are comprehensible, logical, in good order, easily readable,...(11 items). About the fat advice: I think the fat advice is interesting, credible, logical, comprehensible, personal relevant, confusing, complete, too long,...(14 items). And finally about using a computer for this intervention: I think the computer program is user-friendly, clear, a good choice for this intervention, well styled,...(nine items). In sum this resulted in 34 questions. Before the evaluation questionnaire was used, it was first pre-tested among 15 people not participating in this study.
Data reduction and statistical analyses
The 34 items on the evaluation questionnaire were reduced to seven scales and five single items. Based on factor analysis items that matched well were put together in a scale, making it easier to overview and interpret the results. Cronbach Alpha's were used to control for internal consistency between these items. However, some items were too important to be put together, and in order to allow unequivocal interpretation they were kept single.
In order to have sufficient analysis power contemplation and preparation groups and action and maintenance groups, were taken together so that three motivational levels could be distinguished: (1) pre-contemplators, (2) contemplators and perparators, (3) respondents in the action and maintenance stage.
In the results section, item means (not scale means) are often accompanied by percentages, providing additional information. These percentages represent participants who answered 4 (agree) or 5 (totally agree) on the acceptability and feasibility questionnaire items.
All the analyses were performed using SPSS 11.0. Independent-samples t-tests were used to explore differences according to sex, age groups (20–40 and 41–60 years), education (low and high) and computer literacy (low and high) on acceptability and feasibility items or scales. One-way ANOVAs were used to explore differences in stages of change on acceptability and feasibility items or scales. Tukey-test was used for post-hoc analyses. A p-value <0.05 was considered to be significant for all analyses.
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RESULTS |
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TOPSUMMARYINTRODUCTIONMETHODSRESULTSDISCUSSIONREFERENCES |
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Total sample means
As shown in Table 2, most participants were positive about the diagnostic tool (mean scores range from 1 = I don't agree at all to 5 = I totally agree). The total sample mean (3.96 ± 0.57) indicated that respondents indeed thought that intervention questions were comprehensible, easy to fill in, had clear answering options, were in a logical and predictable sequence. The same goes for the readability, style, grammar and instructions that accompanied the intervention questions (4.17 ± 0.58). However, a number of participants also indicated that there were too many intervention questions (2.33 ± 1.15), expressed as a percentage this means that 19.4 % of them reported there were too many questions.
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The majority of participants reported that the Fat Intake Advice is interesting, relevant or useful, taught them new things and gave the impression that it was personally written for them (total sample mean is 3.86 ± 0.70). In addition, positive scores were found when asked if the advice was logical, conveniently arranged, comprehensible, styled well and complete (3.73 ± 0.68). In line with this, few participants indicated that the fat intake advice was too long, confusing or gave too much information (2.06 ± 0.69). Further, 75.8% of the respondents said the fat intake advice was credible (3.87 ± 0.75) and only 14.9% of them indicated that the advice was not correct (3.61 ± 1.05). Despite these very positive scores not everybody was willing to change their behaviours (3.42 ± 0.91): 48.8% indicated they would use the advice, 11.8% will not use it and 39.3% were undecided.
In general most participants indicated that the computer program was user-friendly, conveniently arranged and a good choice for this intervention (4.16 ± 0.66). Only 11.2% of participants reported that they would rather do a written test compared with a computerized intervention (1.96 ± 1.07). Even a smaller proportion reported having problems with colours, presentation and styling used in the computer program (1.81 ± 0.85).
Differences in acceptability and feasibility between groups
Females indicated significantly more that the fat intake advice was correct [t(206) = 2.18, p < 0.05] and significantly less that they had problems with colours, presentation and styling used in the computer program [t(212) = 2.94, p < 0.01] than men.
Participants >40 years of age reported more often that the fat intake advice was credible [t(213) = 2.52, p < 0.05]; that the advice was logical, conveniently arranged, comprehensible, well styled and complete [t(213) = 2.83, p < 0.01]; that they were going to use the advice [t(209) = 4.42, p < 0.001]; that the advice was correct [t(206) = 3.04, p < 0.01] and that they would rather do a written test [t(212) = 3.31, p < 0.01] compared with participants <40 years.
Contemplators and preparators indicated more that the fat intake advice was credible [F(2,203) = 7.03, p < 0.001]; that the advice was interesting, relevant or useful, personally written for them and taught them new things [F(2,203) = 4.69, p < 0.01]; that the advice was logical, conveniently arranged, comprehensible, well styled and complete [F(2,203) = 5.07, p < 0.01]; that they were going to use the advice [F(2,200) = 19.80, p < 0.001] and that the advice was correct [F(2,205) = 7.03, p < 0.001] compared with pre-contemplators and participants in action or maintenance stage. Finally, pre-contemplaters reported significantly more compared with the two other groups that the advice was too long, confusing and gives too much information [F(2,202) = 3.37, p < 0.05].
Participants with computer literacy indicated more that the computer program was user-friendly, conveniently arranged and was a good choice for this intervention [t(211) = 3.30, p < 0.001] and indicated less that they rather did a written test [t(210) = 4.74, p < 0.001] compared with respondents without computer literacy.
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DISCUSSION |
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TOPSUMMARYINTRODUCTIONMETHODSRESULTSDISCUSSIONREFERENCES |
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The results of the present study indicated that the interactive fat intake intervention is a feasible and acceptable tool for intervening in a general population. When compared with a previous feasibility and acceptability study about physical activity almost all feasibility and acceptability scores in this study are better (Vandelanotte and De Bourdeaudhuij, 2003
). This is remarkable, also because participants in this study had indicated being slightly less familiar using a computer. That is probably due to some specific changes made to this intervention based on the acceptability and feasibility testing of the physical activity intervention. A progression indicator was added into the programs software, which gave participants a good idea of how many questions they still had to answer before the individualized feedback appears on the computer screen. Further, an overview of questions to come was given prior to every new part in the fat intake questionnaire and more efforts were made to improve lay out, style and logical sequence of intervention parts.
Participants did not report having problems with the diagnostic tool. Nearly all the participants accepted the appearance and the content of these questions. However, almost 20% of them indicated that they had to answer too many questions before the fat intake advice appeared. It is true that there are a lot of questions that need to be answered, in sum each participant will have to answer up to 75 questions. However, providing a solid and reliable individualized advice that tailors fat intake as well as psychosocial determinants is only possible after answering lots of questions. It is possible that people in general expect that whenever they work on a computer ‘things’ must go fast. In a previous feasibility and acceptability study concerning a physical activity intervention (Vandelanotte and De Bourdeaudhuij, 2003), which had only 50 questions, yet 34% of the participants indicated that there were too many intervention questions. We might thus conclude that a great improvement had been made, probably due to the progression indicator and question overviews.
The majority of participants reported that the appearance as well as content and credibility of the Fat Intake Advice were good, and consequently only a small amount of participants indicated that the advice was too long or confusing. However, a small group of 
15% reported that the fat intake advice is not correct at all. This is probably due to the fact that a lot of people believe that their fat intake is not too high, while in reality it is (Brug et al., 1994; Glanz et al., 1997). These people will not have expected to receive a negative advice, and a part of them might not agree with that, indicating that the advice is wrong. As described earlier, a large percentage of the population has a lack of fat intake awareness, which is a major barrier in interventions aimed at reducing fat intake (Brug et al., 1994). In that respect one might even conclude that 15% is a low score. Further, almost half of all participants intended to use the fat intake advice. This can be interpreted as a positive result, 55% of our respondents were already in the action or maintenance stage being convinced of no need to change their fat intake. Moreover, 28% of our participants were in the pre-contemplation stage and pre-contemplators are known to have a high resistance against adoption of new health behaviours (Prochaska et al., 1994).
Although overall fat intake advice acceptability and feasibility scores were high, significant differences were found between groups for stages of change on all variables. People in the contemplation and preparation stage were consistently more positive about the fat intake advice compared with people in the pre-contemplation, action and maintenance stages. This is in line with the stages of change theory (Brug et al., 1994). Contemplators and preparators intend to change their fat intake and are expected to be more open to intervention materials. In addition, pre-contemplators reported more that the advice was confusing, too long and gave too much information, compared with people in other stages of change. Pre-contemplators have been found to have lower knowledge levels about the health behaviour, and typically try to avoid learning about their health problems (Prochaska et al., 1994; Kristal et al., 1999).
Age also influenced acceptability and feasibility scores of the fat intake advice. People older than 40 years of age consistently reported being more positive about the advice and had higher intentions to use it compared with those younger than 40 years. This is probably because older people encounter more health problems in their everyday life as compared with younger people; consequently they will also care more about their health, which was also observed in other studies (Zunft et al., 1997).
In general, all results concerning the use of a computer indicate that this aspect of the intervention is also acceptable and feasible, all scores were very high. Participants clearly appreciate the use of a computer, which ensures, in a fast and simple way, an immediate and reliable fat intake advice that can be printed and taken home at once. Few significant differences between groups were found, and most of them are self-evident. Almost 20% of all the participants had low computer literacy and still only 11.2% of the participants indicated that they would rather do a written test.
In the present study a convenience sample was used, leading to an overrepresentation of white-collar workers and participants with a higher education. However, specific analyses revealed that the intervention succeeded to tailor well for people from different demographics and stages of change. Derived from the few significant differences between groups for sex, education and computer literacy we can conclude that this intervention tailors well for these groups. Concerning the age groups and stages of changes it is clear that the differences found are logical and in concordance with theories. Furthermore, it must be noted that wherever a significant difference appeared, the acceptability and feasibility scores for each subgroup were still very high. This stresses the importance of the efforts that have been made to tailor the intervention to people from different subgroups.
In sum, the results of this study show that the interactive computer-tailored fat intake intervention is an acceptable and feasible tool for reducing fat intake for respondents having different stages of change, ages, sexes, education levels and computer literacy. No real changes are needed to increase acceptability or feasibility. However, a pre-test-post-test randomized experimental-control group study is necessary to identify whether this intervention is also effective in reducing fat intake in a general population in Belgium. In delivering this intervention, special attention needs to be given to the time required to go through the computer program, to prevent that a number of participants drop out before receiving the health-enhancing feedback.
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