Health Education Research Advance Access originally published online on August 24, 2004
Health Education Research 2005 20(2):195-205; doi:10.1093/her/cyg111
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Health Education Research Vol.20 no.2, © Oxford University Press 2005; All rights reserved
Determinants of forward stage transitions: a Delphi study
1 Department of Health Education and Promotion, Universiteit Maastricht, 6200 MD, Maastricht, The Netherlands, 2 Department of Public Health, Erasmus Medical Center, 3000 DR, Rotterdam, The Netherlands and 3 Department of Social and Organizational Psychology, University of Groningen, 9712 TS, Groningen, The Netherlands
4 Correspondence to: E. de Vet; E-mail: e.devet{at}gvo.unimaas.nl
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Abstract |
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Insight into stage transition determinants is necessary to develop and evaluate stage-tailored health-promoting interventions. A three-round Delphi study among stages of change researchers was conducted to make an inventory of opinions and examine agreement on determinants of forward transitions between Transtheoretical stages of change. In the first round, 10 experts completed an electronic questionnaire with open-ended questions about potential determinants for each stage transition. In the second round, a structured electronic questionnaire based on the first round results was sent to authors of scientific papers on stages of change, published between 1995 and May 2002. In the third round, participants were presented feedback about the second round and were asked to re-rate their answers based on the information provided. Results showed that participants agreed on various transition determinants, but that determinants were not always stage-specific, e.g. control-related issues and social support were identified as determinants of all transitions from contemplation to maintenance. The results further showed lower consensus about determinants of earlier stage transitions than about determinants of later stage transitions. The Delphi study identified hypotheses worthy of further examination in longitudinal observational and experimental studies.
Insight into stage transition determinants is necessary to develop and evaluate stage-tailored health-promoting interventions. A three-round Delphi study among stages of change researchers was conducted to make an inventory of opinions and examine agreement on determinants of forward transitions between Transtheoretical stages of change. In the first round, 10 experts completed an electronic questionnaire with open-ended questions about potential determinants for each stage transition. In the second round, a structured electronic questionnaire based on the first round results was sent to authors of scientific papers on stages of change, published between 1995 and May 2002. In the third round, participants were presented feedback about the second round and were asked to re-rate their answers based on the information provided. Results showed that participants agreed on various transition determinants, but that determinants were not always stage-specific, e.g. control-related issues and social support were identified as determinants of all transitions from contemplation to maintenance. The results further showed lower consensus about determinants of earlier stage transitions than about determinants of later stage transitions. The Delphi study identified hypotheses worthy of further examination in longitudinal observational and experimental studies.
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Introduction |
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The stages of change concept from the Transtheoretical Model (TTM) (Prochaska et al., 1992
) has been widely used as a basis for planning health promotion interventions (Prochaska et al., 1993; Naylor et al., 1999), as an indicator for effects of health promotion interventions (Brug and Van Assema, 2000; Resnicow et al., 2003) and to examine determinants of health behavior change (Brug et al., 1997; Plotnikoff et al., 2001; Ma et al., 2002). The TTM construes behavior change as a dynamic process involving progress through a series of five so-called Stages of Change: precontemplation (no intention to change behavior within the next 6 months), contemplation (intention to change behavior within the next 6 months), preparation (intention to change behavior within 30 days), action (people changed from unhealthy to healthy behavior within the past 6 months) and maintenance (maintenance of the behavior change for more than 6 months). According to the TTM, people can move forward and backward through the stages of change, but none of the stages will be skipped.
The proposed staged character of behavior change has important implications for research and practice in the area of health education and promotion, since stage theories imply that a central goal for health education and promotion should be to promote forward transitions through the stages to attain lasting behavior change. This can be achieved by matching health promotion interventions to stage of change through targeting those variables that can induce forward transitions through the stages (Redding et al., 1999). To adequately develop interventions matched to stage of change, information about these variables or forward transition determinants is needed.
The TTM suggests some of these determinants, such as self-efficacy, decisional balance, processes of change and temptation (Prochaska and Velicer, 1997), and a large number of other alternative potential determinants have been suggested in the literature, e.g. attitude, subjective norm, social support, intention, affect, awareness, comparison to others, commitment to act, dispositional risk factors and vulnerability [see (Santi et al., 1994; Brug et al., 1997; De Vries and Mudde, 1998; Courneya et al., 2001; Ronda et al., 2001; Van Duyn et al., 2001; Segan et al., 2002)].
In the past two decades, a wide range of research and practice based on the TTM in many different health-related domains has been executed. Integration of these findings and perspectives is necessary to gain an overview in what we have learned about determinants of forward transitions so far and how this knowledge can be used to improve health promotion practice. By means of a Delphi methodology, the present study aimed to provide such an overview by (1) making an inventory among stages of change researchers of opinions on forward stage transition determinants and (2) identifying the extent to which participants agree on these determinants. The results of the present study will be compared to findings from longitudinal studies in the Discussion.
Although forward stage transition determinants might vary by behavior, the present study did not focus on one specific behavior, since it attempted to integrate concepts and perspectives into an overall systematic inventory on stage transition determinants.
Delphi methodology versus systematic literature review
Several authors have underlined the usefulness of Delphi methodology in health (promotion) research (McKenna, 1994; Jones and Hunter, 1995; Green and Kreuter, 1999; De Meyrick, 2003). As De Meyrick [(De Meyrick, 2003), p. 7] phrased it:
...the Delphi method is particularly well suited to health issues. On many important health issues, there is a relatively small group of acknowledged experts whose knowledge is the only real guide to best practice in relation to the issue of concern.This usefulness of the Delphi technique originates in its central characteristics (1) anonymity—protecting the Delphi results from the influences of group conformity, prestige, power and politics; (2) iteration—Delphi procedure taking place over a number of rounds, allowing individuals to change their opinion; (3) controlled feedback—between rounds, results of the previous round are communicated; and (4) statistical group response – a device to assure that the opinion of every member of the group is equally represented in the final response (Pill, 1971
; Linstone and Turoff, 1975; Rowe et al., 1991). The Delphi method enables working with a variety of target group representatives and large numbers of participants can be handled. Further, a Delphi methodology can be helpful in situations where face-to-face discussions are impractical (Green and Kreuter, 1999). One might argue that for an integration of findings and perspectives on stage transition determinants a systematic literature review or meta-analysis would be the most appropriate research method. However, since the designs used in stages of change research differ greatly, a comparison of these studies would be difficult. For example, longitudinal designs provide stronger tests of stage transition determinants, but not many have been conducted to date. Further, most studies evaluate stage transition determinants based on a single-theory perspective and therefore only examine a few concepts in relation to stage transition. The Delphi methodology provides the opportunity to derive from a multiple-theory perspective without the limitations of a systematic review or meta-analysis.
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Methods |
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A three round Delphi study was conducted assessing two sorts of agreement. First, the extent to which each expert individually agrees with a statement that the factor under consideration determines stage transition. We refer to this sort of agreement as ‘agreement with stage transition determinant’, representing the individual ratings of a potential stage transition determinant. Second, the extent to which experts collectively agree on the potential stage transition determinant under consideration. We refer to this sort of agreement as ‘consensus’, representing the distribution of opinions of all experts. This distinction is made since the main interest of the present study was to identify determinants that experts collectively rate as an important predictor of stage transition, although it is possible that participants collectively agree (small distribution) that the factor under consideration does not determine stage transition (low rating).
All questionnaires of the three-round Delphi study were pre-tested among experts in the field of health promotion research.
First round
Procedures and participants
Research and practice into staging behavior change varies greatly, e.g. in health topic studied, the theoretical framework used, study methods and materials developed. Since the first round was mainly used to generate a list of possible transition determinants and diversity was of importance, the first round experts had to be representative for the variety in research and practice. Therefore, a heterogeneous sample of experts from different professional fields was recruited (health promotion, health education, marketing, psychotherapy, etc.). These experts all had experience with theory-based research or practice into staging behavior change. An invitation letter to participate in all three rounds of the Delphi study, together with the first round questionnaire, was sent by E-mail to a selection of 18 experts on stages of change. The experts were asked to complete the questionnaire and return it by E-mail. They were also offered the opportunity to complete the questionnaire by telephone. Two weeks after the questionnaires were sent out, non-responders received a reminder. Ten experts completed the first round interview, nine by E-mail and one by telephone. Six experts were not able or willing to complete the interview and two did agree to participate, but did not complete the first round questionnaire in time to be included in the development of the questionnaire for the second round.
Questionnaire
An electronic questionnaire consisting of nine open-ended questions was used in the first round, asking about potential predictors of stage transition. For each stage transition, experts were asked to name factors that predicted the stage transition, e.g. ‘Which factors do you think predict contemplation of behavioral change among people with no initial intention to change?’. The first round questionnaires were primarily conducted to provide input for the second round questionnaire.
Data analyses
For each question, all answers were written down in a list. Answers that described the same variable were gathered into one item. Three researchers did this separately and differences in interpretations were discussed. The analysis resulted in a list of possible predictors of stage transitions ordered by stage.
Second round
Procedures and participants
The second round sample consisted of authors of scientific papers published between 1995 and May 2002, with stages of change in the title or keywords, which were identified through a literature search in PsychInfo and Medline. This search revealed 272 publications. Since some people were first author on more than one publication, the study population consisted of 235 first authors of whom 186 correct E-mail addresses could be retrieved. If the first author's E-mail address could not be identified, the second author's address was tried. In total, 203 persons were invited to participate by an E-mail letter including a link to an electronic questionnaire. Two reminders were sent, 2 and 5 weeks after the invitation E-mail letter. The second reminder also included a question to examine non-response. In total, 77 respondents (38% response rate) completed the questionnaire, including 11 who were not first authors and eight respondents from the first round.
Questionnaire
For the second round, a structured 77-item electronic questionnaire (see http://www.gvo.unimaas.nl/test/delphi.asp) was developed, based on the possible determinants identified by the experts in the first round. Twenty-one items represented potential determinants of the transition from precontemplation to contemplation. Twenty-five items operationalized possible determinants of the transition from contemplation to preparation. Ten and 17 items represented possible determinants of the transition from preparation to action and from action to maintenance, respectively. For each stage transition an extra item ‘other, namely...’ was included, so participants could suggest determinants not put forward by the first round participants and therefore not included in the questionnaire. Items were presented in alphabetical order. For each stage transition, participants were asked to rate on a seven-point Likert scale, ranging from –3 (fully disagree) to 3 (fully agree), to what extent they agreed with statements about possible predictors and correlates of the relevant stage transition. Examples of items are: ‘I think that transition from the precontemplation stage to the contemplation stage is associated with anticipated regret about not behaving in a healthy/precautionary way’ or ‘I think that transition from the preparation stage to the action stage is associated with self-efficacy to behave in a healthy/precautionary way’. For all items an ‘I don't know’ answer option was included.
Data analyses
Delphi studies generally use median scores to summarize the first sort of agreement, i.e. agreement with a statement. A median score represents the value below and above which half the cases fall, the 50th percentile. The second sort of agreement, consensus, is generally calculated by using interquartile deviations (IQDs) (Jones and Hunter, 1995). IQD represents the distance between the 25th percentile and the 75th percentile values in opinions, with a smaller IQD indicating larger consensus. An IQD 
1 can be considered as good consensus on a seven-point Likert scale (Linstone and Turoff, 1975). An IQD 1 means that more than 50% of all opinions falls within one point on the scale. In the present study, for each item median ratings and IQDs were calculated to assess the extent to which respondents collectively agreed with the stage transition determinant under consideration.
Third round
Procedures and participants
The third round sample (N = 73) consisted of all respondents of the second round, provided that they had indicated they were willing to participate further by entering their name or E-mail address in the second round questionnaire. After 3.5 weeks a reminder was sent. Forty-nine respondents completed the questionnaire (24% response rate, 67% of second round participants), of which five respondents were first round participants.
Questionnaire
In the third round, the second round questionnaire with feedback on the second round group results (median and IQD) was presented to participants. According to the Delphi methodology, items on which consensus was obtained in the second round (IQD 1) were excluded from the third round questionnaire (see http://www.gvo.unimaas.nl/test/delphi3.asp). The questionnaire consisted of 55 items. Participants were asked to complete the questionnaire and to re-rate their answers based on the information provided.
Data analyses
In the third round, group median ratings and IQDs were again analyzed. For each of the four stage transitions, changes in consensus between the second and third round were assessed using Wilcoxon signed-rank tests. Differences in IQDs between the second and third round were computed for each item within a stage transition. Next, these differences were ranked and positive and negative ranks were summed. When the sum of positive ranks is significantly different from the sum of the negative ranks, there is a change in consensus for that particular stage transition. All statistical analyses were conducted using SPSS 11.0.
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Results |
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First round
As said, the first round questionnaire was primarily conducted to provide input for the second round questionnaire. Therefore, the second round questionnaire represents the first round group results as depicted in the items in Table I.
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Second round
Table I shows the results of the second round. In this second round, consensus was obtained on 18 items (IQD
1). For eight of these 18 items also agreement (Mdn = 3) was established. All eight items were either in the transition from preparation to action (issues related to self-efficacy such as actual skills, commitment to act, overcoming practical barriers and self-efficacy) or in the transition from action to maintenance [issues related to (perceived) control such as coping skills to resist temptations to revert to unhealthy/risky behavior, self-efficacy to maintain healthy/precautionary behavior and skills to cope with difficult situations that may hinder healthy/precautionary behavior, and automatism such as the extent to which behaving in a healthy/precautionary way has become habitual]. In total 15 of the 18 items on which consensus was obtained had a median score 
2, representing the ‘strongly agree with the item’ opinion.
Largest consensus among respondents was obtained about determinants of the latter stage transitions. For the preparation to action transition, consensus was obtained on five out of 10 items. Least consensus was achieved for the precontemplation to contemplation transition, where only 1 out of 21 items resulted in an IQD 1 (see Table II).
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Third round
Consensus and agreement with stage transition determinants
In the third round, consensus was achieved for 29 items (IQD
1). None of these items revealed a median score of three (fully agree with the item, Table I). Thirteen items had a median score of two, representing the ‘strongly agree with the item’ opinion, and another 13 items had a median score of one, representing the ‘slightly agree with the item’ option. Respondents strongly agreed that the transition from precontemplation to contemplation is determined by awareness-related factors such as awareness of the personal relevance of changing unhealthy/risky behavior, experiencing a symptom that might be related to unhealthy/risky behavior and the environmental re-evaluation process of change. Respondents also strongly agreed that implementation intentions, offer of help from others, self-efficacy and self-esteem could be determinants of the transition from contemplation to preparation. Social support was considered to determine transition from preparation to action.
The action–maintenance transition was perceived to be determined by feedback-related issues like feedback about success, feedback from respected others, physiological reactions and psychological reactions to behaving in a healthy/precautionary way, and the difficulty of behaving in a healthy/precautionary way.
For the precontemplation to contemplation transition, consensus was obtained on 6 out of 20 items. For the contemplation to preparation transition, consensus was obtained on 12 out of 19 items. For the transitions from preparation to action stage and from action to maintenance, consensus was obtained for three out of five and eight out of 11 items, respectively (Table II). Table III provides a summary of items on which consensus was obtained for each of the stage transitions.
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Changes in consensus
In the third round significant changes in consensus were found for all stage transitions. For determinants of the transition from precontemplation to contemplation (z = –3.42; P = 0.001), from contemplation to preparation (z = –3.62; P = 0.001), from preparation to action (z = –2.03; P = 0.042) and from action to maintenance (z = –2.83; P = 0.005) larger consensus was found in the third round as compared to the second round.
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Discussion |
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The present study aimed to make a systematic inventory of opinions of experts on determinants of forward transitions in Transtheoretical stages of change. The results showed that the respondents agreed on various stage transition determinants, but also that these determinants were not always stage-specific. In sum, awareness-related issues were considered to be important in the early stage-transitions between precontemplation and preparation. The concept of implementation intentions was identified as an important determinant for transitions between contemplation and action. Self-efficacy and (perceived) control-related issues, as well as social support were identified as important determinants of all transitions from contemplation to maintenance. Consensus was obtained on only few stage-specific determinants: decisional balance was considered important for the contemplation–preparation transition, commitment to act for preparation to action and different feedback possibilities about the (effects of the) behavior change for action to maintenance. The results will be discussed per stage transition and compared to previous studies. This comparison will be made with prospective studies, since such studies are better suited to identify predictors of stage transitions then cross-sectional studies.
The role of awareness in the precontemplation-contemplation stage transition has been proposed and studied before. For example, De Bourdeaudhuij and Brug (De Bourdeaudhuij and Brug, 2000) have shown in a randomized trial, that making people aware of their personal intake levels of dietary fat did result in stronger intentions. The role of the consciousness-raising process, which is similar to awareness, has also been studied longitudinally but no evidence for transition prediction was found (Herzog et al., 1999).
According to respondents, issues related to awareness and control, implementation intentions, social support and decisional balance might determine the transition from contemplation to preparation. No studies are known on the role of implementation intentions and self-esteem in stage transitions. A few prospective studies supported the idea that social support might play a role in the transition from contemplation to preparation (De Vries and Mudde, 1998; Courneya et al., 2001). Further, some prospective studies have been conducted to investigate the role of decisional balance in early stage transitions in smoking cessation with inconsistent results. Velicer et al. (Velicer et al., 1999) found that measures of pros and cons effectively detect changes as individuals move between stages of change. Etter and Perneger (Etter and Perneger, 1999) only found support for the cons, whereas others (Dijkstra et al., 2003; De Vet et al., 2004) did not find any support for pros and cons as predictors of stage transition from contemplation to preparation. Self-efficacy or perceived behavioral control has been found to be related to progressing from contemplation (Courneya et al., 2001; Armitage et al., 2004; De Vet et al., 2004), although other studies identified self-efficacy to be most important for progress from preparation (De Vries and Mudde, 1998; Dijkstra et al., 2003).
Once someone is in preparation, initiating behavior change seems, according to the respondents in the present study, to be related to skills, implementation intentions, overcoming practical barriers, self-efficacy, social support and commitment to act. As far as we know, to date no formal stages of change-related prospective analyses have been done on skills, implementation intentions and practical barriers as potential transition determinants. Nevertheless, a number of studies have pointed out that implementation intentions can be effective in bridging the intention–behavior gap (Gollwitzer, 1999; Sheeran, 2002). Segan et al. (Segan et al., 2002) have found support for commitment to act and self-efficacy as predictors of the transition from preparation to action. Courneya et al. (Courneya et al., 2001) examined the role of social support, but did not find this concept predictive of progression from preparation.
Control and feedback-related issues can be related to maintaining the initiated behavior change according to the respondents. In the area of addictive behaviors a focus has been on strategies to maintain behavior change, so-called relapse prevention. One of the central ideas in relapse prevention is that addictive habits can be changed through the application of self-control procedures (Marlatt and Gordon, 1985). Not much is known from empirical literature about relapse prevention in relation to the action–maintenance transition. Most prospective studies done on stage transitions either do not make a distinction between action and maintenance stages (Velicer et al., 1999; Courneya et al., 2001; Plotnikoff et al., 2001) or focus on the pre-action stage transitions only (De Vries and Mudde, 1998; Etter and Perneger, 1999; Herzog et al., 1999; Segan et al., 2002). Dijkstra et al. (Dijkstra et al., 2003) specifically examined the transition from action to maintenance and found indications that lower scores on pros of smoking and higher scores on self-efficacy were relevant factors for forward stage movement for people in smoking cessation action. Armitage et al. (Armitage et al., 2004) also found higher scores on self-efficacy to be predictive of progress from action in dietary fat reduction.
A notable finding of the present study is that consensus about earlier stage transitions falls far behind consensus about determinants of later stage transitions. In the first round more possible determinants were identified for the early stage transitions (e.g. precontemplation to contemplation) than for the later stage transitions. Also, in the second and third round, lower IQDs and higher median scores were found for determinants of later transitions from preparation to action and from action to maintenance, showing larger consensus on determinants of these stage transitions. These results may reflect the strong emphasis in health education and promotion programmes on getting people to action. Before stages of change models came into fashion, behavior change has implicitly been regarded as a two-stage process, from unhealthy to healthy behavior. Most experience may therefore be with action-initiating interventions. The fact that more potential determinants of the earlier stage transitions were proposed might also indicate that these stage transitions are more complex, including more potential stage transition determinants, dependent on the behavior under study.
Some limitations of this Delphi study must be discussed. First, the respondents may not be representative for ‘all’ experts on stages of change, due to non-optimal response rates. However, when using mail questionnaires a response rate of 38% is not exceptional (Swanborn, 1987). Lack of time was the main reason reported for not participating in the Delphi study, indicating that non-response was not related to attitude towards stages of change. Furthermore, the study population (except for the first round) consisted only of authors of papers on stages of change. This may have led to biased results. However, the respondents represented authors of papers very critical as well as very supportive toward stage of change. An additional limitation lies within the group process. Since participants were not offered the opportunity to justify their opinions by use of argumentation, all participants' opinions were regarded as equally important. Besides, most authors conducted only a single study on TTM, while others have conducted several studies. Possibly, some participants were more experienced with TTM than others.
Since the time investment that can be asked from participants is limited, only forward stage transition determinants were studied, although we acknowledge that backward transition determinants are also interesting for behavior change and these might differ from forward transition determinants. However, as noted in the introduction, from a planned health promotion perspective an integration of forward stage transition determinants would be more interesting, since motivating people to adopt and maintain healthier lifestyles is one of the central goals in the field.
To conclude, the present study revealed some integrative insights into stage transition determinants from a multiple-theory perspective, based on knowledge and experiences from experts in the field. It would have been complex to derive these insights from the literature, because most empirical studies have only included few possible stage change determinants and some potential stage change determinants have not been studied in relation to stages of change yet (e.g. implementation intentions). The Delphi study approach thus provided the opportunity to identify a broader spectrum of potential stage transition determinants. A next step would be to conduct experimental and longitudinal studies to test if these determinants do predict forward stage transitions.
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Acknowledgments |
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This research was supported by a grant from ZonMW, Netherlands Organization for Health Research and Development.
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Received on March 27, 2004; accepted on June 23, 2004
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  T. P. Lintonen, A. I. Konu, and D. Seedhouse Information technology in health promotion Health Educ. Res., June 1, 2008; 23(3): 560 - 566. [Abstract] [Full Text] [PDF]
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R. Crutzen, J. de Nooijer, W. Brouwer, A. Oenema, J. Brug, and N. K. de Vries Internet-delivered interventions aimed at adolescents: a Delphi study on dissemination and exposure Health Educ. Res., June 1, 2008; 23(3): 427 - 439. [Abstract] [Full Text] [PDF]
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E. de Vet, J. de Nooijer, N. K. de Vries, and J. Brug Testing the transtheoretical model for fruit intake: comparing web-based tailored stage-matched and stage-mismatched feedback Health Educ. Res., April 1, 2008; 23(2): 218 - 227. [Abstract] [Full Text] [PDF]
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E. de Vet, J. de Nooijer, N. K. de Vries, and J. Brug Comparing stage of change and behavioral intention to understand fruit intake Health Educ. Res., August 1, 2007; 22(4): 599 - 608. [Abstract] [Full Text] [PDF]
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B. Schuz, F. F. Sniehotta, and R. Schwarzer Stage-specific effects of an action control intervention on dental flossing Health Educ. Res., June 1, 2007; 22(3): 332 - 341. [Abstract] [Full Text] [PDF]
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