THE READINESS TO CHANGE QUESTIONNAIRE IN SUBJECTS WITH HAZARDOUS ALCOHOL CONSUMPTION, ALCOHOL MISUSE AND DEPENDENCE IN A GENERAL POPULATION SURVEY

Wolfgang Hannöver,*, Jochen René Thyrian, Ulfert Hapke, Hans-Jürgen Rumpf1, Christian Meyer and Ulrich John

Ernst-Moritz-Arndt-University Greifswald, Institute of Epidemiology and Social Medicine, Greifswald and
1 Medical University of Lübeck, Department of Psychiatry and Psychotherapy, Research Group S:TEP (Substance Abuse: Treatment, Epidemiology, and Prevention), Lübeck, Germany

Received 24 August 2001; in revised form 15 December 2001; accepted 25 January 2002


    ABSTRACT
 TOP
 FOOTNOTES
 ABSTRACT
 INTRODUCTION
 SUBJECTS AND METHODS
 RESULTS
 DISCUSSION
 ACKNOWLEDGEMENTS
 REFERENCES
 
Aims: To investigate properties and aspects of validity of the Readiness to Change Questionnaire (RCQ) when applied to hazardous drinking, alcohol-abusing or alcohol-dependent subjects sampled from the general population. Methods: In a representative survey conducted in the general population of a region in northern Germany, participants were randomly selected from resident registration office files, contacted and interviewed personally (n = 4.075). A total of 302 subjects who showed hazardous drinking behaviour (n = 202) or met diagnostic criteria of alcohol misuse (n = 46) or alcohol dependence (n = 54) were assessed and diagnosed using the Munich Composite International Diagnostic Interview (M-CIDI) according to DSM-IV diagnostic criteria. The battery of self-report questionnaires comprised, among others, the RCQ, and two methods of allocation were used, the quick method and the refined method of allocation. According to the method of allocation used, the stages are: precontemplation (PC), contemplation (C), preparation (P) and action (A); P may only be assigned using the refined method. Results: The RCQ, a brief instrument to assess stages of change in individuals sampled from the general population, gave internal consistencies of: PC = 0.68, C = 0.79, A = 0.83. Allocation to stages of change according to the quick method resulted in 67% of subjects being allocated to PC, 24% to C and 8% to A and according to the refined method in 58% to PC, 15% to C, 4% to P, 4% to A, with 19% not being classified because of non-theory-consistent scale profiles. Conclusions: Classification did not differ substantially according to the method of allocation. A three-factor solution, as reported in the literature, could not be replicated. Allocation to stages of change with the RCQ reflected predictions made from the Transtheoretical Model of behaviour change.


    INTRODUCTION
 TOP
 FOOTNOTES
 ABSTRACT
 INTRODUCTION
 SUBJECTS AND METHODS
 RESULTS
 DISCUSSION
 ACKNOWLEDGEMENTS
 REFERENCES
 
From the public health aspect, restriction of access and secondary prevention, especially in combination, curtails negative consequences from substance use and misuse most effectively (Holder et al., 1997Go; Ponicki et al., 1997Go; Cordoba et al., 1998Go; John et al., 1998Go). Considering motivational background in interventions enhances effectiveness of secondary prevention (Velicer et al., 1993Go; Hapke et al., 1996Go; Miller, 1996Go; Samet et al., 1996Go; Dijkstra et al., 1998Go; contradicting: Ashworth, 1997Go). The Transtheoretical Model of behaviour change (Prochaska and DiClemente, 1982Go; Prochaska et al., 1992Go) proposes that behaviour change successively follows five consecutive stages of change: precontemplation (PC), contemplation (C), preparation (P), action (A) and maintenance (M). Tailoring intervention strategies to these stages results in: (1) higher abstinence rates (Velicer et al., 1993Go); (2) enhanced utilization of system resources (Hapke et al., 1996Go); (3) optimized use of healthcare system resources (John et al., 1998Go). Stage allocation is done either using staging algorithms, where actual behaviour and plans to change this behaviour are assessed (DiClemente et al., 1991Go; Donovan et al., 1998Go) or by multidimensional questionnaires (McConnaughy et al., 1983Go; Miller and Tonigan, 1996Go; Rollnick et al., 1992Go; overview, Carey et al., 1999Go). Sutton (1996, 2001) and Weinstein et al. (1998) criticized: (1) the formulation of the stages of change as distinct stages within the Transtheoretical Model; (2) the different methods to measure stages of change.

The Readiness to Change Questionnaire (RCQ) (Rollnick et al., 1992Go) is a 12-item self-report questionnaire. Heather et al. (1993) proposed two methods of stage allocation, the quick and the refined method. The quick method assesses three stages of change: precontemplation (PC), contemplation (C) and action (A). The refined method of stage allocation also assesses preparation (P). An alternative allocation scheme using factor scores is described by Hapke (2000). The RCQ has been developed and applied in brief and opportunistic interventions among hazardous drinkers in general practices and wards of general hospitals. Reliability estimates from these settings were satisfactory (Rollnick et al., 1992Go; Rodriguez Martos et al., 2000Go). Applying the RCQ to clients undergoing alcohol-specific treatment (McMahon and Jones, 1996Go; Gavin et al., 1998Go) results in certain difficulties. Heather et al. (1999) addressed these with the treatment version of the RCQ. Evidence of predictive validity has also been gathered from clinical samples (Heather et al., 1993Go; McMahon and Jones, 1996Go; Hapke, 2000Go). Construct validity has been investigated by analysing the factor structure of the RCQ. A three-factor structure, reflecting the stages PC, C and A, was found in different studies (Rollnick et al., 1992Go; Wells Parker et al., 1998Go; Hapke, 2000Go; Rodriguez Martos et al., 2000Go). Budd and Rollnick (1996) used a structural equation modelling technique and found that a model with correlating factors and a model with a second-order factor fit the data equally well.

The aims of the present study are: (1) to report item and scale properties (item difficulty, item selectivity, scale distributions and internal consistencies); (2) to investigate construct validity of the RCQ, when applied to subjects from the general population who show hazardous alcohol consumption, alcohol misuse or dependence.

Construct validity of the RCQ was investigated in two steps. In the first step, allocation to stage of change using the alternative allocation algorithms proposed by Heather et al. (1993) for subjects from the general population were compared with allocations resulting from studies using clinical samples. Since there are differences in prevalence rates of alcohol use and misuse between samples drawn from the general population and samples drawn from patient populations (Bronisch and Wittchen, 1992Go; Perkonigg et al., 1998Go; Rumpf et al., 1999Go, contradicting Cherpitel, 2000Go), application of the instrument to subjects from the general population contributes to knowledge on strengths and limitations in utilization of the RCQ. Comparing samples from different studies is very difficult — differences between studies may be attributable to a host of reasons — and a detailed comparison of the samples is beyond the scope of this article. However, comparison of the allocation rates, with these limitations in mind, may be useful, in gauging what proportions of subjects may be expected from patient or general populations. In a second step, factor analysis was performed for the data under study. We investigated whether the three-factor structure found in patients on general hospital wards and general practices can be replicated with subjects from the general population.

Results from our analyses may serve as estimates for item and scale properties and provide information on validity of the RCQ if applied to hazardous consuming, alcohol-abusing or -dependent subjects from the general population. With regard to stages of change, we expect larger proportions of subjects to be in earlier stages of change, compared to subjects from patient samples. With regard to the three subgroups defined by different drinking patterns, we expect higher proportions of alcohol-abusing or -dependent subjects to be in later stages than hazardously consuming subjects.


    SUBJECTS AND METHODS
 TOP
 FOOTNOTES
 ABSTRACT
 INTRODUCTION
 SUBJECTS AND METHODS
 RESULTS
 DISCUSSION
 ACKNOWLEDGEMENTS
 REFERENCES
 
This article is based on the Transition in Alcohol Consumption and Smoking (TACOS) study. TACOS is a survey on substance use, misuse and dependence among the adult population in a rural and urban region in northern Germany. The aims of TACOS were: (1) to estimate prevalence rates of substance misuse and dependence in the given region; (2) to investigate individual and environmental factors pertaining to substance use and misuse with a focus on alcohol and nicotine (Hapke et al., 1998Go). The methodology of the study is matched with other epidemiological projects in Germany within the scope of the research network ‘Analytical Epidemiology of Substance Abuse’ (ANEPSA, 1998Go).

The survey assessed a representative sample of 4075 individuals, constituting a recruitment efficacy rate (Stang et al., 1999Go) of 70.2%. Meyer et al. (2000a) provided a detailed description of the population, sampling and response patterns. The main diagnostic tool in the survey was the computer-assisted Munich–Composite International Diagnostic Interview (M-CIDI) (Wittchen et al., 1995Go). The M-CIDI used for this survey comprises 14 sections containing questions relevant for diagnosis of psychological disorders according to ICD-10 (World Health Organization, 1993Go) and DSM-IV (American Psychiatric Association, 1995Go). A detailed description of procedures and quality assurance for the interviews is found in Meyer et al. (2000b). Depending on results from the M-CIDI, study staff handed out self-report questionnaires to respective subgroups of subjects. A detailed description of procedures and instruments may be found in Hapke et al. (1998) and in Hess et al. (1998).

Subjects
For this study, a subgroup of 302 subjects was analysed in more detail. Of these, 202 subjects met criteria for hazardous drinking behaviour at the time of assessment. Hazardous drinking was defined according to the criteria proposed by the British Medical Association (Bradley et al., 1993Go) (i.e. 20 g alcohol per day for women and 30 g of alcohol per day for men). Of the remaining subjects, 46 met criteria for alcohol misuse and 55 subjects met criteria for alcohol dependence. One of the 55 alcohol-dependent subjects did not complete the RCQ and was dropped from analyses, leaving 54 subjects who met the criteria for alcohol dependence. Allocation to one of these three classes was mutually exclusive. Compared to other prevalence estimates for alcohol misuse and dependence in Germany (Bronisch and Wittchen, 1992Go; Nelson and Wittchen, 1998Go; Bühringer et al., 2000Go), these rates are lower. However, this estimate is in accordance with regional differences in alcohol consumption in Germany (Meyer et al., 1998Go), where per capita consumption rates in the southern regions of Germany are higher than in northern Germany. Table 1Go provides a brief description of the subjects under study.


View this table:
[in this window]
[in a new window]
 
Table 1. Age, sex, marital and employment status of the survey sample, broken down by drinking behaviour
 
All differences between the subgroups under study (n = 302 hazardous consumers, alcohol misusers and alcohol dependants) and survey subjects not meeting these criteria (n = 3773) (non-hazardous) are statistically significant; sex: {chi}2 = 59.4, d.f. = 1, P < 0.001; employment status: {chi}2 = 13.44, d.f. = 5, P = 0.02; marital status: Fisher's exact test = 21.5, P < 0.001. For age, variances in the two groups were not equal (F = 9.6, P = 0.002), and means between groups differed significantly (t = –2.2, P = 0.032).

All differences between subgroups under study (hazardous consumers, alcohol misusers and alcohol dependants) were significant (sex: {chi}2 = 11.8, d.f. = 2, P = 0.003; employment status: Fisher's exact test = 17.9, P = 0.026; marital status: Fisher's exact test = 18.9, P = 0.007). Age differed significantly between groups (F = 20.4, d.f. = 2, P < 0.001).

Assessments
The RCQ consists of 12 items on a 5-point rating scale ranging from ‘strongly disagree’ (–2) to ‘strongly agree’ (2). The respective four items comprising one subscale (Rollnick et al., 1992Go) are summed. This results in three subscales PC, C and A, ranging from –8 to + 8. Since the RCQ was designed to assign subjects to motivational stages, emphasis has been put on techniques of stage allocation (Heather et al., 1993Go). The two methods used contemporaneously are the ‘quick method’ and the ‘refined method’ of stage allocation. The quick method assigns subjects according to the highest subscale score. In the case of a tie, the stage chosen is the furthest stage of change reached. Assignment becomes arbitrary when subjects score high or equal on more than just one subscale and/or show only gradual differences in scale scores.

On closer inspection of profiles in scale scores, Heather et al. (1993) found that, if distinctiveness of stages was taken strictly (only positive scores on one subscale with scores of zero or negative scores on the remaining two subscales), a consistent classification was possible in only 40% of subjects investigated. This, along with logical inconsistencies in interpretation of scale profiles, led to the refined method of stage allocation (Heather et al., 1993Go). The refined method analyses the relationship of positive and negative scale scores as a profile of three scores. The P stage of change may be allocated. The allocation scheme is as follows: (1) subjects scoring positive on PC and negative on both C and A are classified as being in PC; (2) subjects scoring positive on C and negative on both PC and A are classified as being in C; (3) subjects with negative scores in PC and positive scores in both C and A, and with a higher score in C than A, are allocated to P; (4) subjects with negative scores in PC and positive scores in both C and A, and a C score lower or equal to the A score are allocated to A. The refined method leads to a logically more consistent assignment, but results in a certain proportion of cases that cannot be allocated. In a sample of 174 excessive drinkers in general practices or on a general hospital ward, 40 subjects (23% of the total sample) could not consistently be assigned to one of the four stages (Heather et al., 1993Go).

Translation
RCQ items were translated into German. Items resulting in double negative phrases, if rated, were adapted. The translation was checked and translated back into English by a native speaker. Resulting differences due to adaptation were inspected and discussed in terms of item content. The phrasing which best captured the original content of the item, without rendering double negative phrases, was retained for the survey.

Statistical analysis
Proportions were complemented with 95% confidence bands of the estimates (the assumption that proportions distribute normally is made throughout for confidence estimates). Reliability was estimated via internal consistency (Cronbach's alpha). Factors were extracted using principal components analysis with the Kaiser–Guttman criterion and were subsequently varimax-rotated. Between-group comparisons were made according to scaling and distributional shape of variables either using analysis of variance or Kruskal–Wallis rank-sum test. Analyses were performed using SPSS Version 10.0.7 for Windows and S-Plus 2000© for Windows.


    RESULTS
 TOP
 FOOTNOTES
 ABSTRACT
 INTRODUCTION
 SUBJECTS AND METHODS
 RESULTS
 DISCUSSION
 ACKNOWLEDGEMENTS
 REFERENCES
 
Distributions, scale and item properties
Since distributions of raw scores are very skewed for C and A and very flat for PC, reporting statistical parameters such as arithmetic means or SD as summarizing statistics would be misleading. Interquartile ranges for the three subscales are: A: –8, –6, –4; C: –6, –3, 1; P: –1, 2, 4. Opposed to the C and A scales, on the PC scale, most subjects scored in the positive range of the scale, with two peaks of 17% scoring 4 and 12% scoring 8. The mean rankings between the three subscales differed significantly between the subgroups (PC: {chi}2 = 32.47, d.f. = 2; C: {chi}2 = 55.54, d.f. = 2; A: {chi}2 = 20.46, d.f. = 2). Part–whole corrected item selectivity scores, item difficulty scores and internal consistencies for the three subgroups are reported in Table 2Go.


View this table:
[in this window]
[in a new window]
 
Table 2. Item difficulty and selectivity scores for Readiness to Change Questionnaire (RCQ) items, internal consistency estimates for RCQ subscales precontemplation (P), contemplation (C), action (A), with regard to the whole sample and three subgroups: hazardous consumption, alcohol misuse, alcohol dependence
 
The least difficult item for all three groups collapsed and for hazardous consumption and alcohol misuse this was: ‘There is no need for me to think about changing my drinking’ (item 10). For the group of subjects meeting criteria for alcohol dependence, the least difficult item was: ‘I enjoy my drinking, but sometimes I drink too much’ (item 3). The most difficult item for all groups (collapsed and analysed separately) was: ‘I am actually changing my drinking habits now’ (item 11).

Stage allocation
The RCQ's relevant information in order to allocate subjects to stages of change lies in the relationship between scores, rather than in the magnitude of scores. Allocation to stage of change using the quick method results in 67 ± 5% being allocated to PC, 24 ± 5% to C and 8 ± 3% to A. Using the refined method results in 58 ± 5% being allocated to PC, 15 ± 4% to C and 4 ± 2% to A; 12 subjects (4 ± 2%) were allocated to P and 56 subjects (19 ± 4%) did not show scores conforming to the model and could not therefore be allocated to any stage. Table 3Go shows a cross-tabulation of allocations resulting from the quick and refined methods.


View this table:
[in this window]
[in a new window]
 
Table 3. Cross-tabulation of allocation to stages of change with the Readiness to Change Questionnaire using quick vs refined method of allocation
 
When classification was possible, the two methods resulted in similar classifications of subjects; 234 or 77% of subjects were allocated to the same stage using either method. However, the methods differ in two respects. (1) Using the refined method of allocation, 56 subjects (19%) could not be allocated to any stage. With regard to allocation using the quick method, this affects subjects from later stages to a larger degree (13% allocated to PC, 25% to C and 48% to A). (2) All subjects allocated to P using the refined method had been allocated to C using the quick method.

Table 4Go shows stage allocation according to the quick and refined method, from this study, and compares the results with those of Hapke (2000)Go, Heather et al. (1993) and Rodriguez Martos et al. (2000).


View this table:
[in this window]
[in a new window]
 
Table 4. Proportions and 95% confidence limits of subjects allocated to stages of change according to the quick method and the refined method for subjects with at least hazardous consumption of alcohol from the TACOS survey compared to data from other studies
 
Despite the difficulties in comparing estimates from different samples, allocation to stages of change results in rather similar rates for the three patient samples. In contrast, allocation of the subjects from our general population sample was clearly different.

Using the refined method, without taking the P stage into account, classification to stages of change results in 36 ± 7% of subjects who could not be classified in the study from Heather et al., and 23 ± 5% in this study. If classification to the additional P stage is taken into account, the rate of subjects who cannot be classified is reduced to 37 (22 ± 6%) in the study from Heather et al. and to 56 (19 ± 4%) in the present study. In the other two studies on patient samples, allocation according to the refined method is not reported.

Comparing allocation methods for the three subgroups under inspection (hazardous consumption, alcohol misuse and dependence) (Table 5Go) revealed that allocation to stage of change differed considerably between subgroups and also between methods. Differences are due to allocation to P and those subjects who could not be allocated. Regardless of the allocation method, subjects with hazardous consumption or those meeting criteria for alcohol misuse were mostly allocated to PC, with the smallest number of subjects allocated to A. The majority of alcohol-dependent subjects was allocated to C, with second most subjects being allocated to PC, and more allocated to A compared with the other two groups.


View this table:
[in this window]
[in a new window]
 
Table 5. Relative frequencies of allocation to stages of change according to the quick method for three levels of alcohol consumption (hazardous drinking, alcohol misuse and dependence)
 
Factor analysis
Principal component analysis extracted two components with eigenvalues of >1. After varimax rotation, the first factor accounted for 30.7% of the variance, the second for an additional 30%, with a total of 60.8% of variance explained. The factor loadings after rotation are reported in Table 6Go. Items belonging to PC loaded negatively on the first factor. Items belonging to C showed high positive loadings on the first factor. Items belonging to A loaded highest on the second factor. However, three of the four items belonging to PC also loaded negatively on the second factor and two of the four items from C loaded similarly on both factors.


View this table:
[in this window]
[in a new window]
 
Table 6. Varimax-rotated component matrix of factor loadings of the Readiness to Change Questionnaire items
 

    DISCUSSION
 TOP
 FOOTNOTES
 ABSTRACT
 INTRODUCTION
 SUBJECTS AND METHODS
 RESULTS
 DISCUSSION
 ACKNOWLEDGEMENTS
 REFERENCES
 
The RCQ has been developed to assess motivational stages of change according to the Transtheoretical Model in order to select counselling strategies with regard to the motivational background and to enhance treatment impact in brief and opportunistic interventions with subjects currently not being in treatment for alcohol-related problems. The instrument shows good psychometric properties and predictive validity when applied to a sample of high-risk alcohol consumers treated in general hospital wards or general practices. These findings were replicated in different groups of patients in different countries.

Analyses of standard psychometric properties, such as item selectivity, item difficulty and internal consistency in this study support the item selection. As was expected, item difficulty scores differed between the three subgroups. While items from PC had the highest difficulty scores for hazardous consumers, items from C and A had the highest difficulty scores for alcohol-dependent subjects. Internal consistencies from different translations and different groups of subjects produced estimates similar to those for hazardous drinkers, alcohol misusers and alcohol dependants from the general population. These results speak in favour of the item selection, their translations and their organization in three subscales corresponding to the three stages of change. In this study, distribution of raw scores was very flat for the PC and very skewed for the C and A scales. Since allocation to stage of change is the main objective of administration, rather than interpretation of raw scores, distributional qualities do not interfere with interpretation of test results.

Allocation to stage of change showed the expected distribution, given the subjects under inspection. In contrast to the patient samples, the majority of subjects was allocated to PC. Differential inspection showed that the majority of subjects showing either hazardous drinking behaviour or alcohol misuse were allocated to PC. A larger proportion of alcohol-dependent subjects was allocated to C. These results are also in accordance with predictions from the Transtheoretical Model and may be taken as further aspects of construct validity. The comparison between patient and non-patient samples, however, has to be put into perspective. While the overall comparison between patients and the group in this study differed markedly in allocations to stages of change, this difference decreased noticeably if only alcohol-misusing and alcohol-dependent subjects from this study are compared with the subjects from the patient groups. However, neither subgroup in this study showed a consistently similar pattern in stage allocation comparable to the patient samples. This may be taken as an indicator that differences in motivational stages of change between general hospital or general practice patients and subjects from the general population are not only due to drinking behaviour. Rather, being confronted with their health status as prompting a visit with a healthcare expert may have served as a trigger for the patients to re-evaluate their alcohol consumption behaviour. The higher proportions of patients allocated to the A stage also supports this interpretation.

Allocation to stage of change did not show strict model conformity in 22% of subjects. If the refined method was used and P as stage of change was taken into account, this rate was reduced to 19%. Compared to the patient sample, this rate is considerably lower, indicating that it is easier to allocate subjects to stages of change if they are sampled from the general population. Nevertheless, a classification scheme that conflicts in every fifth to every third subject with the underlying model or results in an inconclusive classification leaves room for further improvement. Allocation methods produced comparable results for the three subgroups under inspection (hazardous consumption, alcohol misuse, alcohol dependence). This reflects a general shortcoming of the allocation scheme, rather than a differential incompatibility between method and subjects under inspection.

Principal component analysis produced inconclusive results. In contrast to the theoretical formulation and background, only two components with eigenvalues of >1 could be extracted. At a first glance, it looks inviting to interpret the first factor as a bipolar representation of a continuum with PC on one end, and C on the other, and the second factor as a unipolar representation of A. However, items from PC and C showed similar loadings on both factors. Nor did analysing subgroups result in an interpretable structure; and indications for a single factor solution were not found. It looks likely that these results derive from the item distributions that do not agree with distribution assumptions necessary for factor analyses. Thus, no conclusions concerning the factor structure of the RCQ may be drawn from this study.

In conclusion, the RCQ is a brief instrument with satisfying psychometric properties, that enables quick allocation to stages of change of subjects with at least high-risk drinking behaviour, if sampled from the general population. Classification results are in accordance with predictions from the Transtheoretical Model for behaviour change and may be taken as valuable hints for construct validity of the instrument. Results from factor analysis, however, are jeopardized by item distribution characteristics and do not allow a conclusion about the factor structure of the RCQ, thus weighing against the instrument's construct validity. Finally, another methodological shortcoming may be seen in the rate of subjects who showed scores without strict model conformity.


    ACKNOWLEDGEMENTS
 TOP
 FOOTNOTES
 ABSTRACT
 INTRODUCTION
 SUBJECTS AND METHODS
 RESULTS
 DISCUSSION
 ACKNOWLEDGEMENTS
 REFERENCES
 
This study is part of the German research network ‘Analytical Epidemiology of Substance Abuse (ANEPSA)’. Factors related to the use and misuse of psychoactive substances are analysed by different research groups in the context of several longitudinal studies. Contact persons are: Dr Bühringer/Dr Küfner (IFT Institute for Therapy Research Munich), Prof. Dr Wittchen (Max-Planck-Institute Munich), Prof. Dr John (University of Greifswald)/Prof. Dr Dilling (Medical University of Lübeck). The research network is funded in the context of the programme ‘Biological and Psycho-social Factors of Drug Abuse and Dependence’ by the Federal Ministry of Education, Science, Research and Technology. Data described in this paper are part of the project ‘Transitions in Alcohol Consumption and Smoking (TACOS)’, part 1: ‘Drug Use in the Adult General Population in a Northern German City and Surrounding Communities’, grant no. 01 EB 9406; principal investigators: Prof. Dr John (University of Greifswald), Prof. Dr Dilling (Medical University of Lübeck).


    FOOTNOTES
 TOP
 FOOTNOTES
 ABSTRACT
 INTRODUCTION
 SUBJECTS AND METHODS
 RESULTS
 DISCUSSION
 ACKNOWLEDGEMENTS
 REFERENCES
 
* Author to whom correspondence should be addressed at: Ernst-Moritz-Arndt-Universität Greifswald, Institute of Epidemiology & Social Medicine, Walther-Rathenau-Str. 48, D-17487 Greifswald, Germany. Back


    REFERENCES
 TOP
 FOOTNOTES
 ABSTRACT
 INTRODUCTION
 SUBJECTS AND METHODS
 RESULTS
 DISCUSSION
 ACKNOWLEDGEMENTS
 REFERENCES
 
American Psychiatric Association (1995) Diagnostic and Statistical Manual of Mental Disorders, 4th edn. American Psychiatric Association, Washington, DC.

ANEPSA (1998) German Research Network ‘Analytical Epidemiology of Substance Abuse’ (ANEPSA). European Addiction Research 4, 203–204.[ISI][Medline]

Ashworth, P. (1997) Breakthrough or bandwagon? Are interventions tailored to stage of change more effective than non-staged interventions? Health Education Journal 56, 166–174.

Bradley, K. A., Donovan, D. M. and Larson, E. B. (1993) How much is too much? Archives of Internal Medicine 153, 2734–2740.[Abstract]

Bronisch, T. and Wittchen, H.-U. (1992) Lifetime and six-month prevalence of abuse and dependence of alcohol in the Munich Follow-up Study. European Archives of Psychiatry and Clinical Neuroscience 241, 273–282.[ISI][Medline]

Budd, R. J. and Rollnick, S. (1996) The structure of the Readiness to Change Questionnaire: a test of Prochaska & DiClemente's transtheoretical model. British Journal of Health Psychology 1, 365–376.[ISI]

Bühringer, G., Augustin, R., Bergmann, E., Bloomfield, K., Funk, W., Junge, B., Kraus, L., Merfert-Diete, C., Rumpf, H.-J., Simon, R. and Töppich, J. (2000) Alkoholkonsum und alkoholbezogene Störungen in Deutschland [Consumption of alcohol and alcohol-related disorders in Germany], Vol. 128. Nomos, Baden-Baden.

Carey, K. B., Purnine, D. M., Maisto, S. A. and Carey, M. P. (1999) Assessing readiness to change substance abuse: a critical review of instruments. Clinical Psychology, Science and Practice 6, 245–266.[Abstract]

Cherpitel, C. J. (2000) Drinking patterns and alcohol dependence: a comparison of primary care patients in a southern county with the regional general population. Journal of Studies on Alcohol 61, 130–133.[ISI][Medline]

Cordoba, R., Delgado, M. T., Pico, V., Altisent, R., Fores, D., Monreal, A., Frisas, O. and Lopez del Val, A. (1998) Effectiveness of brief intervention on non-dependent alcohol drinkers (EBIAL): a Spanish multi-centre study. Family Practice 15, 562–568.[Abstract/Free Full Text]

DiClemente, C. C., Prochaska, J. O., Fairhurst, S. K., Velicer, W. F., Velasquez, M. M. and Rossi, J. S. (1991) The process of smoking cessation: an analysis of precontemplation, contemplation, and preparation stages of change. Journal of Consulting and Clinical Psychology 59, 295–304.[ISI][Medline]

Dijkstra, A., Roijackers, J. and De Vries, H. (1998) Smokers in four stages of readiness to change. Addictive Behaviors 23, 339–350.[ISI][Medline]

Donovan, R. J., Jones, S., Holman, C. D. A. J. and Corti, B. (1998) Assessing the reliability of a stage of change scale. Health Education Research 13, 285–291.[ISI][Medline]

Gavin, D. R., Sobell, L. C. and Sobell, M. B. (1998) Evaluation of the readiness to change questionnaire with problem drinkers in treatment. Journal of Substance Abuse 10, 53–58.[ISI][Medline]

Hapke, U. (2000) Sekundärpräventive Interventionen bei einer Alkoholproblematik im Allgemeinkrankenhaus [Secondary preventive interventions in subjects with alcohol problems in the general hospital]. Lambertus, Freiburg i. Br.

Hapke, U., Rumpf, H.-J. and John, U. (1996) Beratung von alkoholabhängigen Patienten im Allgemeinkrankenhaus [Counselling alcohol dependent patients in the general hospital]. In AlkoholKonsum und Mißbrauch, AlkoholismusTherapie und Hilfe, Deutsche Hauptstelle gegen die Suchtgefahren (DHS) ed., pp. 345–354. Lambertus, Freiburg i. Br.

Hapke, U., Rumpf, H.-J., Meyer, C., Dilling, H. and John, U. (1998) Substance use, abuse and dependence among the adult population in a rural and urban region of Northern Germany. European Addiction Research 4, 208–209.[ISI][Medline]

Heather, N., Rollnick, S. and Bell, A. (1993) Predictive validity of the Readiness to Change Questionnaire. Addiction 88, 1667–1677.[ISI][Medline]

Heather, N., Luce, A., Peck, D., Dunbar, B. and James, I. (1999) Development of a treatment version of the Readiness to Change Questionnaire. Addiction Research 7, 63–83.[ISI]

Hess, D., Gilberg, R., Jesske, B. and Meyer, C. (1998) Lebensgewohnheiten und Gesundheit in Lübeck und Umgebung [Life-style and health in Lübeck and the surrounding communities]. Infas Sozialforschung, Lübeck.

Holder, H. D., Saltz, R. F., Grube, J. W., Treno, A. J., Reynolds, R. I., Voas, R. B. and Gruenewald, P. J. (1997) Summing up: lessons from a comprehensive community prevention trial. Addiction 92 (Suppl. 2), S293–S301.[ISI][Medline]

John, U., Hapke, U. and Rumpf, H.-J. (1998) Der bevölkerungsbezogene Gesundheitsansatz und Konsum psychotroper Substanzen [The population-oriented health approach and the consumption of psychotropic substances]. Zeitschrift für Gesundheitswissenschaften 6, 58–74.

McConnaughy, E. A., Prochaska, J. O. and Velicer, W. F. (1983) Stages of change in psychotherapy: measurement and sample profiles. Psychotherapy: Theory, Research and Practice 20, 368–375.[ISI]

McMahon, J. and Jones, B. T. (1996) Post-treatment abstinence survivorship and motivation for recovery: the predictive validity of the Readiness to Change (RCQ) and Negative Alcohol Expectancy (NAEQ) Questionnaires. Addiction Research 4, 161–176.[ISI]

Meyer, C., Rumpf, H.-J., Hapke, U. and John, U. (1998) Regionale Unterschiede in der Prävalenz riskanten Alkoholkonsums: Sekundäranalyse des Gesundheitssurveys Ost-West. [Regional differences in the prevalence of hazardous alcohol consumption: secondary analysis of the health-survey east-west Germany]. Gesundheitswesen 60, 486–492.[Medline]

Meyer, C., Rumpf, H.-J., Hapke, U., Dilling, H. and John, U. (2000a) Prevalence of alcohol consumption, abuse and dependence in a country with high per capita consumption: findings from the German TACOS study. Social Psychiatry and Psychiatric Epidemiology 35, 539–547.

Meyer, C., Rumpf, H.-J., Hapke, U. and John, U. (2000b) The Composite International Diagnostic Interview: feasibility and necessity of editing and interviewer training in general population surveys. International Journal of Methods in Psychiatric Research 9, 32–42.

Miller, W. R. (1996) Motivational interviewing: research, practice, and puzzles. Addictive Behaviors 21, 835–842.[ISI][Medline]

Miller, W. R. and Tonigan, J. S. (1996) Assessing drinkers' motivations for change: The Stages of Change Readiness and Treatment Eagerness Scale (SOCRATES). Psychology of Addictive Behaviors 10, 81–89.[ISI]

Nelson, C. B. and Wittchen, H.-U. (1998) DSM-IV alcohol disorders in a general population sample of adolescents and young adults. Addiction 93, 1065–1077.[ISI][Medline]

Perkonigg, A., Lieb, R. and Wittchen, H. U. (1998) Substance use, abuse and dependence in Germany. A review of selected epidemiological data. European Addiction Research 4, 8–17.

Ponicki, W., Holder, H. D., Gruenewald, P. J. and Romelsjo, A. (1997) Altering alcohol price by ethanol content: results from a Swedish tax policy in 1992. Addiction 92, 859–870.[ISI][Medline]

Prochaska, J. O. and DiClemente, C. C. (1982) Transtheoretical therapy: toward a more integrative model of change. Psychotherapy: Theory, Research and Practice 19, 276–288.[ISI]

Prochaska, J. O., DiClemente, C. C. and Norcross, J. C. (1992) In search of how people change. Applications to addictive behaviors. American Psychologist 47, 1102–1114.[ISI][Medline]

Rodriguez Martos, A., Rubio, G., Auba, J., Santo Domingo, J., Torralba, L. and Campillo, M. (2000) Readiness to Change Questionnaire: reliability study of its Spanish version. Alcohol and Alcoholism 35, 270–275.[Abstract/Free Full Text]

Rollnick, S., Heather, N., Gold, R. and Hall, W. (1992) Development of a short ‘Readiness to Change’ Questionnaire for use in brief, opportunistic interventions among excessive drinkers. British Journal of Addiction 87, 743–754.[ISI][Medline]

Rumpf, H.-J., Hapke, U., Meyer, C. and John, U. (1999) Motivation to change drinking behavior: Comparison of alcohol-dependent individuals in a general hospital and a general population sample. General Hospital Psychiatry 21, 348–353.[ISI][Medline]

Samet, J. H., Rollnick, S. and Barnes, H. (1996) Beyond CAGE. A brief clinical approach after detection of substance abuse. Archives of Internal Medicine 156, 2287–2293.[Abstract]

Stang, A., Ahrens, W. and Jöckel, K. H. (1999) Control response proportions in population-based case–control studies in Germany. Epidemiology 10, 181–183.[ISI][Medline]

Sutton, S. R. (1996) Can ‘stages of change’ provide guidance in the treatment of addictions? A critical examination of Prochaska and DiClemente's model. In Psychotherapy, Psychosocial Treatments and the Addictions, Edwards, G. and Dare, C. eds, pp. 189–205. Cambridge University Press, Cambridge.

Sutton, S. R. (2001) Back to the drawing board? A review of applications of the transtheoretical model to substance abuse. Addiction 96, 175–186.[ISI][Medline]

Velicer, W. F., Prochaska, J. O., Bellis, J. M., DiClemente, C. C., Rossi, J. S., Fava, J. L. and Steiger, J. H. (1993) An expert system intervention for smoking cessation. Addictive Behaviors 18, 269–290.[ISI][Medline]

Weinstein, N. D., Rothman, A. J. and Sutton, S. R. (1998) Stage theories of health behavior: Conceptual and methodological issues. Health Psychology 17, 290–299.[ISI][Medline]

Wells Parker, E., Williams, M., Dill, P. and Kenne, D. (1998) Stages of change and self-efficacy for controlling drinking and driving: a psychometric analysis. Addictive Behaviors 23, 351–363.[ISI][Medline]

Wittchen, H.-U., Beloch, E., Garczynski, E., Holly, A., Lachner, G., Perkonigg, A., Vodermaier, A., Vossen, A., Wunderlich, U. and Zieglgänsberger, S. (1995) Münchener Composite International Diagnostic Interview (M-CIDI), Version 2.2. Max-Planck-Institut für Psychiatrie, München.

World Health Organization (1993) Tenth Revision of the International Classification of Diseases, Chapter V (F), Mental and Behavioural Disorders, Diagnostic Criteria for Research. World Health Organization, Geneva.