Effects of a Self-Efficacy Intervention on Initiation of Recommended Exercises in Patients With Spondylosis

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1 Journal of Aging and Physical Activity, 2006, 15, , Human Kinetics, Inc. Effects of a Self-Efficacy Intervention on Initiation of Recommended Exercises in Patients With Spondylosis Aleksandra Luszczynska, Agnieszka Gregajtys, and Charles Abraham An intervention designed to enhance preaction self-efficacy beliefs (i.e., beliefs about ability to initiate behavior despite anticipated barriers during the initiation period) was tested in patients with spondylosis in relation to initiation of exercises recommended by a consultant in orthopedic rehabilitation. Sixty patients (age years; 44% men) with spondylosis who had not previously performed exercises recommended for degenerative spine diseases were randomly assigned to a control (education session) or intervention group. Three weeks later, intervention patients performed recommended exercises more frequently than controls. Regression analysis for all patients showed that preintervention, preaction selfefficacy predicted exercise. Age and preintervention self-efficacy moderated the intervention effects. Among older patients, only those with weak preintervention, preaction self-efficacy beliefs benefited from the intervention, whereas among younger patients, only those with strong preintervention, preaction self-efficacy beliefs benefited from the intervention. Key Words: intention, spine, rehabilitation, age Spondylosis is a common degenerative disorder affecting spinal structure and function. The disease leads to damage of facet joints and intervertebral disks and can affect cervical, thoracic, and lumbar regions of the spine (Borenstein, Wiesel, & Boden, 1996). Almost half of all 50-year-olds and 70% of all 60-year-olds develop cervical spondylosis (Borenstein et al.) and, as a consequence, suffer back and neck pain. Fortunately, adherence to specific exercise recommendations can prevent disease progression (Joynt, 1988). A series of social-cognition models have identified modifiable antecedents of behavior that distinguish between people who do and do not perform recommended health behaviors (Conner & Norman, 2005). Foremost among these are self-efficacy beliefs, that is, beliefs about the feasibility of one s success in performing recommended behaviors (Bandura, 1997, 1998). According to social-cognitive theory Luszczynska and Abraham are with the Dept. of Psychology, University of Sussex, Brighton BN19QH UK. Luszczynska is also with the Warsaw School of Social Psychology, Wroclaw, Poland. Gregajtys is with the Dept. of Rehabilitation, Military Institute of Health Services, PL Warsaw, Poland. 26

2 Preaction Self-Efficacy and Exercise 27 (Bandura, 1997), those who believe they will succeed in undertaking a considered action are, in general, more likely to formulate intentions to act, set themselves higher goals, exert greater effort, regard errors as learning experiences, and persevere longer. High self-efficacy beliefs also reduce distraction from anxiety and self-doubt (Bandura, 1988). It is not surprising, then, that self-efficacy beliefs are key predictors of adherence to recommended rehabilitation exercise (Sherwood & Jeffery, 2000). Moreover, intervention studies have demonstrated that self-efficacy beliefs can be enhanced by means of mastery experiences (e.g., setting easy initial tasks that build people s confidence), vicarious experiences, verbal persuasion, or enhancement of positive emotions (Bandura, 1997). Intention to act is an essential prerequisite of action. People who do not intend to undertake health behaviors rarely perform those behaviors (Sheeran, 2002), and self-efficacy beliefs provide a crucial foundation for intention formation. The Health Action Process Approach model (Schwarzer, 2001) differentiates between self-efficacy beliefs and specific effects on action initiation and maintenance. For example, preaction self-efficacy prompts initiation formation, and recovery selfefficacy supports reengagement after lapses (Schwarzer). Preaction self-efficacy beliefs are beliefs concerning one s ability to initiate actions for the first time and to marshal the resources needed to overcome challenges involved in behavioral initiation, such as the need to form action plans and reorganize daily routines (Luszczynska & Schwarzer, 2003). Self-efficacy interventions have been found to increase exercise and thereby slow disease progression among patients with spinal diseases. For example, changes in patients self-efficacy beliefs after verbal persuasion have been found to enhance their ability to perform exercises (Moseley, 2004). Moreover, a selfefficacy intervention using mastery experiences and verbal persuasion was found to be as effective as treatment including lumbar fusion with posterior transpedicular screws and postoperative physiotherapy (Brox et al., 2003). Nonetheless, not all self-efficacy interventions are effective (e.g., Altmaier, Russell, Kao, Lehmann, & Weinstein, 1993). Inconsistencies in research findings might reflect sample differences. In particular, preexisting levels of self-efficacy are likely to affect the potential effectiveness of self-efficacy interventions. For example, in a study of middle-aged and older patients recovering from stroke, Salbach et al. (2005) found that the effectiveness of a self-efficacy intervention was moderated by age and baseline self-efficacy such that older patients with weak baseline self-efficacy showed the greatest increase in both self-efficacy and physical activity after a self-efficacy intervention (cf. Hellström, Lindmark, Wahlberg, & Fugl-Meyer, 2003). Self-efficacy and physical activity decline with age (Gulanik, 1991), and this might be especially true in patients with musculoskeletal problems (Leveille, Cohen- Mansfield, & Guralnik, 2003). Research also suggests that age might moderate associations between cognitions, such as a self-efficacy, and exercise (cf. Hagger, Chatzisarantis, & Biddle, 2002). Thus it is possible that, in general, self-efficacy interventions designed to enhance physical exercise work best with those who have higher preintervention self-efficacy beliefs; that is, these interventions act to bolster and build on preexisting self-efficacy. It is also possible, however, that among older people such interventions have the strongest effects among those with weak preintervention self-efficacy beliefs, that is, those who have suffered the most decline in their excise-related confidence. Certainly, further research into

3 28 Luszczynska, Gregajtys, and Abraham relationships between age, physical activity, and self-efficacy is warranted because of inconsistencies in the existing literature (cf. Parkatti, Deeg, Bosscher, & Launer, 1998; Resnick, 2001). We hypothesized that among patients with spondylosis who had not previously performed recommended exercises, an intervention targeting preaction self-efficacy would promote preaction self-efficacy beliefs and, therefore, initiation of rehabilitation exercises. We also hypothesized moderation effects for preintervention self-efficacy beliefs and age; namely, we expected that older patients would benefit from the intervention regardless of preintervention preaction self-efficacy beliefs, whereas younger patients would benefit more when baseline preaction self-efficacy beliefs were strong. Participants Method Sixty-six patients (37 women and 29 men) who had not performed exercises recommended for spondylosis but had been diagnosed with mild or moderate spondylosis between 1 month and 30 years before data collection (M = 6.60, SD = 7.90) agreed to participate in the study. All had degenerative diseases of the cervical spine (9.3%), thoracic spine (1.9%), or lumbar spine (88.9%) and had had a radiographic examination confirming spondylosis. Overall, 31.5% of participants had co-occurring health problems: 14.8% reported cardiovascular diseases; 14.8%, problems with digestive system; and 3.7%, respiratory-system diseases. Participants were between 28 and 83 years of age (M = 54.54, SD = 14.51); 41% were retired, 21% had primary education, and 42% had secondary education. Six patients did not participate at follow-up, but comparisons of individuals who participated at preand postintervention revealed no significant differences in gender, education, years since diagnosis, prevalence of degenerative disease in the lumbar spine, intention, or self-efficacy (all p >.10). Patients with mild and moderate spondylosis did not differ in terms of co-occurring diseases or spinal region affected by spondylosis. Procedure Data were collected from a convenience sample of patients newly admitted to an orthopedic rehabilitation center in Warsaw, Poland. On arrival, patients were informed about the purpose and design of the study and invited to participate. Personal identifier codes were used to ensure anonymity. A consultant in orthopedic rehabilitation helped patients complete preintervention questionnaires. Patients were then randomly assigned to a control or intervention group. All participants were asked to return 3 weeks later, when postintervention questionnaires were administered. Control Condition A rehabilitation consultant informed patients about recommended rehabilitation exercises. Patients first read a leaflet featuring pictures of all recommended exercises, guidelines on how to perform the exercises, and the recommended duration and frequency of exercises (cf. Frank & Strabl-Betas, 2003). The consultant then

4 Preaction Self-Efficacy and Exercise 29 discussed performance, frequency, and duration of exercises with patients. Patients were encouraged to ask questions and asked to perform a set of initial stretching exercises for 5 min, strengthening exercises for 15 min, and stretching exercises for 10 min every day (cf. Joynt, 1988). Three sets of exercises were recommended, depending on type of spondylosis (see Table 1). Intervention Condition Patients assigned to the experimental condition received the same education session as control patients. Afterward, they participated in an intervention designed to strengthen preaction self-efficacy beliefs by means of a mastery experience and verbal persuasion from an authority figure. The intervention protocol stipulated that patients must perform recommended exercises in the presence of the consultant, be informed when the consultant was convinced that they could successfully initiate recommended exercises, be applauded by the consultant on successful performance of a new exercise, and complete a leaflet referring to past mastery experiences and encouraging initiation of the recommended exercises. Table 1 Examples of Exercises Recommended for Patients With Three Types of Spine Degeneration Type of spine degeneration Cervical Thoracic Lumbar Exercise example 1. While sitting on a chair, interlink your fingers on the back of your head. 2. With the back of your head, press on your palms with your fingers interlinked. 3. Hold while breathing in and out three times. 4. Release the position. 5. Repeat 15 times. 1. Get onto your hands and knees, keeping your arms, thighs, and back fairly straight. 2. Bend slowly and stretch your hands out, moving them on the floor. 3. Try to press your chest in the direction of floor until you feel a comfortable stretch. 4. Breathe in and out six times. 5. Release the position so that you end up on your hands and knees again. 6. Repeat twice. 1. Lie on your back and gently pull your knees to your chest until you feel a comfortable stretch. 2. Hold for 15 seconds. 3. Repeat twice.

5 30 Luszczynska, Gregajtys, and Abraham The leaflet required patients to identify a past event in which action was successfully initiated and answer a series of questions about this success ( Please describe an event when you successfully initiated something [e.g., quitting smoking]? What actions did you take? How did you feel when you succeeded? ). The leaflet also highlighted the importance of past success ( Remember, you have already successfully initiated new actions. Based on your past successes you can strengthen beliefs about your ability to initiate daily performance of the exercises recommended by the consultant ). Patients were told to keep the leaflet and refer to the past mastery experience if they had doubts about their ability to continue with the recommended exercise program. Measures Measures of behavior, preaction self-efficacy, intention to initiate the recommended exercises, and intensity of pain during exercises were taken pre- and postintervention. Accuracy of performance was measured with two items. Patients were presented pictures and verbal descriptions (see Table 1) of two recommended exercises (cf. Frank & Strabl-Betas, 2003) and asked, This was an example of the exercises that you were asked to perform. Have you performed this exercise in the recommended way (i.e., as long as recommended and repeating as many times on one occasion as recommended)? Responses were measured on a scale ranging from definitely have not (1) to definitely have (4). Preintervention data collection confirmed that none of the patients had ever performed either of the exercises preintervention. Combined responses for both exercises ranged from 2 to 8 at postintervention, with a mean sum score of 6.18 (SD = 1.29). Accuracy of performance was correlated for both exercises (r =.62, p <.001). Frequency of performance was measured by one item. Patients were presented with descriptions of the nine recommended exercises and asked, How often have you performed the described exercises above? Responses were made on the scale ranging from never (0) to every day (21), and scores ranged from 0 to 21 (M = 11.76, SD = 8.65). In addition, a global index of performance of recommended exercises was computed as a multiplicative product of accuracy and frequency. Preintervention global-performance index scores were 0 for all patients. At postintervention, globalperformance index scores for recommended exercises ranged from 0 to 126 (M = 50.38, SD = 42.55). Previous work has confirmed the reliability and validity of our preaction selfefficacy measure with patients undergoing cardiovascular rehabilitation (Luszczynska, 2004). The scale consists of three items. The stem Think about the initiation of recommended exercises within next few days. Do you believe that you are able to start to perform recommended exercises at home? was followed by questions, I am confident that I am able to initiate to do recommended exercises even if (a) I have to mobilize myself to start them at once, (b) I have to reorganize my daily routines to find time to exercise, and (c) I have to stop doing some other activities. Responses were made on a 4-point scale ranging from definitely am not (1) to definitely am (4). Summed responses at preintervention ranged from 3 to 12 (M = 9.32, SD = 2.36) and from 5 to 12 at postintervention (M = 9.32, SD = 1.52). Cronbach s alphas for the scale were.90 and.64, respectively.

6 Preaction Self-Efficacy and Exercise 31 Exercise performance can be affected by pain, so we measured intensity of pain during exercises at postintervention using the BS-11 scale (Downie et al., 1978) with possible responses ranging from 0 to 11. Patients reported low pain intensity (M = 2.94, SD = 0.98). In order to control for exercise motivation, preintervention intention to perform recommended exercises was measured with a single item ( The next item refers to performance of nine exercises which you discussed with the consultant in orthopedic rehabilitation: Within the next month I intend to perform recommended rehabilitation exercises every day ; Luszczynska, 2004). Responses were made on a 6-point scale, definitely do not (1) to definitely do (6), and the mean score was 3.20 (SD = 0.98). Data Analysis Analysis of variance was used to test the first two hypotheses concerning the effects of the intervention on preaction self-efficacy and exercise. The third and fourth hypotheses, concerning moderation effects, were tested using multiple-regression analysis (Jaccard & Turrisi, 2003). Note that because patients reported that they had not performed exercises at preintervention, measures of postintervention exercise were equivalent to change indices (difference in raw scores). Predictor and outcome variables for each hypothesis are presented in Table 2. Table 2 Hypotheses and Indices of Controlled Predictor and Outcome Variables in the Study Hypothesis Analysis Predictors Outcomes Intervention promotes selfefficacy. Repeatedmeasures ANOVA Group allocation Preaction selfefficacy Intervention promotes exercise. ANOVA Group allocation Exercise frequency, a exercise accuracy, a combined exercise index a Preintervention self-efficacy moderates effects of the intervention on exercise. Hierarchical regression Group allocation, preaction selfefficacy, Group Preaction Self- Efficacy interaction Exercise frequency, a exercise accuracy, a combined exercise index a Age moderates effects of preintervention self-efficacy and the intervention on exercise. Hierarchical regression Group allocation, preaction selfefficacy, Age Group Preaction Self-Efficacy interaction Exercise frequency, a exercise accuracy, a combined exercise index a a Exercise index scores at preintervention were 0. Postintervention scores therefore represent change (difference in raw scores) between pre- and postintervention.

7 32 Luszczynska, Gregajtys, and Abraham Results Randomization Check and Preliminary Analyses Intervention groups did not differ in intention to initiate recommended exercises, F(1, 49) = 1.03, ns; preaction self-efficacy beliefs, F(1, 49) = 3.89, ns; the spine region affected by the disease, χ 2 (2) = 1.28, n.s.; time elapsed since diagnosis, F(1, 54) = 0.23, n.s.; stage of disease (i.e., moderate vs. mild spondylosis), χ 2 (1) = 0.58, n.s.; co-occurring diseases, cardiovascular: χ 2 (1) = 0.58, n.s.; respiratory: χ 2 (1) < 0.01, n.s.; digestive: χ 2 (1) = 0.59, n.s.; gender, χ 2 (1) = 0.01, n.s.; or age, F(1, 54) = 0.39, n.s. There was also no postintervention difference in intensity of pain during exercises, F(1, 50) = 3.02, n.s. Correlations between study variables are presented in Table 3. Analysis of variance revealed no gender differences for study variables (all p >.10). Effects of the Intervention on Self-Efficacy and Performance of Recommended Exercises It was hypothesized that intervention-group allocation would affect preaction selfefficacy. Repeated-measures ANOVA revealed that there was no main effect of time (i.e., pre- to postintervention) on preaction self-efficacy, F(1, 47) = 0.09, n.s., but there was a time-by-group interaction, F(1, 47) = 6.79, p <.05, η 2 =.13. Among control-group participants, preaction self-efficacy beliefs tended to decrease over the study, F(1, 24) = 3.57, p =.07, Cohen s d = 0.46 (pre: M = 10.12, SD = 2.80; post: M = 9.12, SD = 1.30). By contrast, preaction self-efficacy beliefs tended to increase in intervention-group participants, F(1, 24) = 3.33, p =.08, Cohen s d = 0.46 (pre: M = 8.71, SD = 1.71; post: M = 9.50, SD = 1.74). On the global index of exercise, participants from the intervention group tended to report higher performance of recommended exercises (M = 60.08, SD = 38.74) than did control patients (M = 39.67, SD = 44.27), F(1, 48) = 3.18, p =.08, Cohen s d = The post hoc observed power coefficient was.58 (where alpha =.05). Groups did not differ on the index of exercise-performance accuracy, F(1, 49) = 0.30, n.s., Cohen s d = 0.15, but patients from the intervention group reported more frequent exercise (M = 14.12, SD = 7.63) than did control patients (M = 9.40, SD = 9.09), F(1, 49) = 3.98, p <.05, Cohen s d = 0.56). With the exception of 2 participants from the control group, patients initiated at least some of recommended exercises. Daily performance was reported by 52% of participants from the intervention group and 36% from the control group. Baseline Preaction Self-Efficacy as a Moderator of Intervention Effects We hypothesized that patients with stronger preintervention preaction self-efficacy would benefit from the intervention more than participants with weak preaction self-efficacy beliefs. Postintervention indices of exercise were used as dependent variables, being equivalent to change in exercise between the waves. Hierarchical regression was undertaken to test for moderating effects of baseline preaction selfefficacy on intervention effects. Age, gender (coded as a dummy variable: male = 1,

8 Preaction Self-Efficacy and Exercise 33 Table 3 Correlations Between the Study Variables Variable Time elapsed since diagnosis Intention (T1) Preaction self-efficacy (T1) Preaction self-efficacy (T2) Accuracy of performance (T2) Frequency of performance (T2) Global index of performance (T2) Pain during exercises (T2) Age.27* **.37***.15 Time elapsed since diagnosis Intention (T1).52****.38***.20.24* Preaction selfefficacy (T1).23.31** Preaction selfefficacy (T2) Accuracy of performance (T2).40**.57****.21 Frequency of performance (T2).81****.20 Global index of performance (T2).23 Note. T1 = initial measurement; T2 = follow-up measurement 3 weeks later. *p <.10. **p <.05. ***p <.01. ****p <.001.

9 34 Luszczynska, Gregajtys, and Abraham female = 0), and intention to exercise were controlled for in all analyses. Age and gender were entered at the first step, intention to exercise and baseline preaction self-efficacy at the second step, group allocation at the third step, and an interaction term (Preaction Self-Efficacy Group Allocation) at the fourth step. Results are displayed in Table 4. Table 4 Predictors of Initiation of Recommended Exercises Among Patients With Spondylosis: Results of Three Hierarchical- Regression Analyses Global Index of Exercise Accuracy of Exercise Frequency of Exercise Variable beta R 2 ( ) beta R 2 ( ) beta R 2 ( ) Step gender age.36**.11.28** Step 2.19 (.04).16 (15**).16 (.05) gender age.40***.07.26* intention (pre) preaction selfefficacy (pre).20.36*.06 Step 3.31 (.12***).19 (.03).22 (.06*) gender age.43***.05.28** intention (pre) preaction selfefficacy (pre).32*.43**.05 experimental condition.37***.18.28** Step 4.39 (.08**).24 (.06**).28 (.06**) gender age.36***.13.23* intention (pre) preaction selfefficacy (pre).50***.56***.13 intervention condition.39***.22.29** Intervention Condition Preaction Self- Efficacy.34**.28**.28** p <.10, *p <.05, **p <.01, ***p <.001.

10 Preaction Self-Efficacy and Exercise 35 Table 4 shows that the interaction between group allocation and baseline preaction self-efficacy had an effect on all exercise indices. Procedures outlined by Aiken and West (1991) were used to examine interaction effects. Combinations of high (M + 1 SD) and low (M 1 SD) values of the predictor variables were substituted into the regression equation to enable plotting of regression lines. The results for the global index are displayed in Figure 1. Among participants with weak preintervention self-efficacy, the global exercise index was low in both the intervention and control groups. By contrast, among patients with strong preintervention selfefficacy, intervention-group participants had a higher global index of exercise than did control-group participants. Similar patterns of associations between self-efficacy and group allocation were found for exercise frequency and accuracy. In summary, regardless of group allocation, participants with low preintervention self-efficacy exercised rarely (and with low accuracy). By contrast, intervention participants with strong preintervention preaction self-efficacy exercised more frequently and more accurately than those from the control group did. Age as a Moderator of the Effects of the Intervention Our fourth hypothesis related to the moderating role of age. We expected that older patients would benefit most from the intervention if they had weak preintervention preaction self-efficacy beliefs, and younger patients would benefit more if they had strong preintervention preaction self-efficacy. To test for moderating effects of age, three-way interactions were examined using hierarchical-regression analyses controlling for age, gender, and intention to exercise. Age and gender were entered at Step 1. At Step 2, preintervention self-efficacy and intention were entered, followed Figure 1 Results of regression analysis: Effects of the interaction between experimental condition and baseline preaction self-efficacy on the global index of recommended exercise. Note. For all participants, exercise-index scores at Wave 1 were 0. Scores at Wave 2 therefore represent change (difference in raw scores) between Waves 1 and 2.

11 36 Luszczynska, Gregajtys, and Abraham by the experimental condition at Step 3. At Step 4, two-term interactions (Age Group Allocation, Age Self-Efficacy, and Self-Efficacy Group Allocation) were entered. At the final step, the three-way interaction term was entered (Age Group Allocation Self-Efficacy). Age was treated as a continuous variable. The three-way interaction resulted in a significant increase in R 2 for the global exercise index ( R 2 =.13, p <.01). Variables included in the equation explained 54% of variance in the global exercise index. The three-way interaction term had no effect on accuracy of exercise performance but resulted in a marginal increase in R 2 for exercise frequency ( R 2 =.05, p =.09). Variables included in the equation explained 28% of variance in exercise frequency. Guidelines outlined by Aiken and West (1991) were used to examine three-way interaction effects on the global index of exercise, and these are displayed in Figure 2. Younger patients benefited from the intervention only when their preintervention self-efficacy beliefs were strong. In contrast, older patients benefited from the intervention only where their preintervention self-efficacy beliefs were weak. In addition, older patients with strong preintervention self-efficacy allocated to the control group had global-exercise-index scores as high as those of the patients in the experimental group. Therefore, it can be concluded that effects of the intervention were moderated by age and preintervention preaction self-efficacy. In summary, the intervention only benefited younger patients with strong preexisting preaction self-efficacy and older patients with weak preexisting preaction self-efficacy. Discussion A preaction self-efficacy intervention aided initiation of a rehabilitation exercise in patients with spondylosis. Compared with patients who only participated in an education session, patients who additionally participated in the preaction selfefficacy-promoting intervention were more likely to exercise frequently during the initiation period of 3 weeks. The intervention had a moderate effect on initiation of the recommended exercises. The intervention also enhanced patients beliefs about their ability to initiate the exercises. In addition, preaction self-efficacy beliefs measured before the intervention predicted postintervention exercise behavior. Overall, patients with stronger preintervention preaction self-efficacy beliefs benefited more from the intervention than did those with weak preaction selfefficacy beliefs. This effect was moderated, however, by age, revealing that older patients only benefited from the intervention if they had weak preintervention self-efficacy beliefs, whereas younger patients only benefited if they had strong preintervention self-efficacy beliefs. Our findings support social-cognitive theory (Bandura, 1997), confirming that self-efficacy beliefs are crucial determinants of health behavior. As socialcognitive theory suggests, self-efficacy beliefs were found to predict exercising behavior over and above proximal goals (i.e., intentions).the results also support the Health Action Process Approach model (Schwarzer, 2001), which proposes that preaction self-efficacy beliefs foster action initiation. In addition, our findings correspond to previous results indicating that, in rehabilitation patients initiating exercise, matched phase-specific self-efficacy beliefs are the best predictors of exercise behavior (cf. Lippke, Ziegelmann, & Schwarzer, 2005; Scholz, Sniehotta, & Schwarzer, 2005).

12 Preaction Self-Efficacy and Exercise 37 Figure 2 Results of regression analysis: Effects of the interaction between the experimental condition, baseline preaction self-efficacy, and age on the global index of recommended exercise. Note. For all participants, exercise-index scores at Wave 1 were 0. Scores at Wave 2 therefore represent change (difference in raw scores) between Waves 1 and 2. The moderation effects here support similar previous findings (Salbach et al., 2005) and highlight the importance of age in the application of exercise-promoting exercise interventions. The findings are in line with research showing that even when patients initial self-efficacy is low, older people might exercise more if they

13 38 Luszczynska, Gregajtys, and Abraham participate in a self-efficacy-enhancing intervention (Hellström et al., 2003; Salbach et al.). Indeed, our findings imply that screening older rehabilitation patients initiating exercise and selecting only those with lower initial self-efficacy could maximize the effectiveness of self-efficacy interventions. Our results suggest that older patients with high initial preaction self-efficacy beliefs who received exercise education did not need an additional self-efficacy intervention and so derived no addition benefit from it. In contrast, our intervention required higher levels of preexisting self-efficacy in younger patients to show an additional effect over exercise education. If replicated these findings would have implications for practice. Enhancing beliefs about ability to initiate recommended exercise by means of a self-completion leaflet focusing on a previous mastery experience and using persuasion and encouragement from a doctor can help patients initiate recommended exercises. The intervention tested here is brief, lasting approximately 30 min. We have only tested effectiveness when the intervention was delivered by a physician, but any health-care professional could deliver the intervention. Consequently, such interventions have the potential to be cost-effective and to increase adherence to exercise recommendations in older patients who doubt their ability to initiate exercise. Our study has limitations. Performance of recommended exercises was measured by self-report. Although questions were detailed and included a depiction of the exercises, other outcome measures (such as movement analysis) should be employed in future evaluations. Nonetheless, other studies investigating the effects of psychological interventions on physical-activity-behavior change have also employed self-report measures and suggested that these measures are valid and reliable (cf. Kelley & Abraham, 2004). The main limitation of the study lies in low statistical power. To obtain the recommended power of.80, a larger sample (N = 100) is necessary. This might explain some of the marginal effects observed. The experimental procedures employed also meant that, compared with control participants, the intervention group spent more time with the rehabilitation consultant and had more opportunities to discuss their concerns. Therefore, the intervention-group participants received more attention and could have perceived the consultant as more attentive. Further research should control for attention effects and for patients satisfaction with participation in the research. Finally, because the present study dealt with patients with spondylosis, replication is necessary before the results can be generalized to other patients enrolled in rehabilitation. Although further investigation is required, our results indicate that interventions aiming at initiating novel exercise behaviors should target preaction self-efficacy beliefs specific to targeted exercises. Effects of such intervention might, however, be moderated by age and preexisting self-efficacy beliefs. Younger patients might require an additional intervention to boost existing self-efficacy beliefs before receiving an intervention such as the one tested here, whereas older patients with higher preexisting self-efficacy beliefs might be able to initiate recommended exercise after only receiving educational introduction. Such an intervention might, however, enhance exercise-initiation and adherence in older patients with lower preexisting self-efficacy beliefs.

14 Preaction Self-Efficacy and Exercise 39 References Aiken, L.S., & West, S.G. (1991). Multiple regression: Testing and interpreting interactions. Newbury Park, CA: Sage. Altmaier, E.M., Russell, D.W., Kao, C.F., Lehmann, T.R., & Weinstein, J.N. (1993). Role of self-efficacy in rehabilitation outcome among chronic low back patients. Journal of Counseling Psychology, 40, Bandura, A. (1997). Self-efficacy: The exercise of control. New York: Freeman. Bandura, A. (1998) Health promotion from the perspective of social cognitive theory. Psychology and Health, 13, Borenstein, D.G., Wiesel, S.W., & Boden, S.D. (1996). Neck pain: Medical diagnosis and comprehensive management. Philadelphia: Saunders. Brox, I., Sorensen, R., Friis, A,., Nygaard, O., Asge, I., Keller, A., et al. (2003). Randomized clinical trial of lumbar instrumented fusion and cognitive intervention and exercises in patients with chronic low back pain and disc degeneration. Spine, 28, Conner, M., & P. Norman, P. (Eds.). (2005). Predicting health behaviour: Research and practice with social cognition models. Buckingham, UK: Open University Press. Downie, W.W., Leatham, P.A., Rhind, V.M., Wright, V., Branco, J.A., & Anderson, J.A. (1978). Studies with pain rating scales. Annals of the Rheumatic Diseases, 37, Frank, P., & Strabl-Betas, B. (2003). The prevention of degenerative spine diseases: Exercise program for patients. Blaubeuren, Germany: Ludwig Merkle GmbH. Gulanik, J.M. (1991). Is Phase 2 cardiac rehabilitation necessary for early recovery of patients with cardiac disease? A randomized controlled study. Heart and Lung, 20, Hagger, M.S., Chatzisarantis, N.L.D., & Biddle, S.J.H. (2002). A meta-analytic review of the theories of reasoned action and planned behavior in physical activity: Predictive validity and the contribution of additional variables. Journal of Sport & Exercise Psychology, 24, Hellström, K., Lindmark, B., Wahlberg B., & Fugl-Meyer, A.R. (2003). Self-efficacy in relation to impairments and activities of daily living disability in elderly patients with stroke: A prospective investigation. Journal of Rehabilitation Medicine, 35, Jaccard, J., & Turrisi, R. (2003). Interaction effects in multiple regression. Thousand Oaks, CA: Sage. Joynt, R.L. (1988). Therapeutic exercise. In Delisa, J. (Ed.), Rehabilitation medicine principles and practice (pp ). Philadelphia: JB Lippincott. Kelley, K., & Abraham, C. (2004). RCT of a theory based intervention promoting healthy eating and physical activity amongst out-patients older than 65 years. Social Science and Medicine, 59, Leveille, S.G., Cohen-Mansfield, J., & Guralnik, J.M. (2003). The impact of chronic musculoskeletal pain on exercise attitudes, self-efficacy, and physical activity. Journal of Aging and Physical Activity, 11, Lippke, S., Ziegelmann, J.P., & Schwarzer, R. (2005). Stage-specific adoption and maintenance of physical activity: Testing a three stage model. Psychology of Sport & Exercise, 6, Luszczynska, A. (2004). Zmiana zachowan zdrowotnych [Health behavior change]. Gdansk, Poland: Gdansk Psychological Publisher. Luszczynska, A., & Schwarzer, R. (2003). Planning and self-efficacy in the adoption and maintenance of breast self-examination: A longitudinal study on self-regulatory cognitions. Psychology and Health, 18, Moseley, G.L. (2004). Evidence for a direct relationship between cognitive and physical change during an intervention in people with chronic low back pain. European Journal of Pain, 8,

15 40 Luszczynska, Gregajtys, and Abraham Parkatti, T., Deeg, D., Bosscher, R., & Launer, L. (1998). Physical activity and self-rated health among 55- to 89-year-old Dutch people. Journal of Aging and Health, 10, Resnick, B. (2001). Testing a model of overall activity in older adults. Journal of Aging and Physical Activity, 9, Salbach, N.M., Mayo, N.E., Robichaud-Ekstrand, S., Hanley, J.A., Richards, C.L., & Wood- Dauphinee, S. (2005). The effect of a task-oriented walking intervention on improving balance self-efficacy poststroke: A randomized, controlled trial. Journal of the American Geriatrics Society, 53, Scholz, U., Sniehotta, F.F., & Schwarzer, R. (2005). Predicting exercise in cardiac rehabilitation: The role of phase-specific self-efficacy. Journal of Sport & Exercise Psychology, 27, Schwarzer, R. (2001). Social-cognitive factors in changing health-related behavior. Current Directions in Psychological Science, 10, Sheeran, P. (2002). Intentions-behavior relations: A conceptual and empirical review. European Review of Social Psychology, 12, Sherwood, N.E., & Jeffery, R.W. (2000). The behavioral determinants of exercise: Implications for physical activity interventions. Annual Review of Nutrition, 20,