Abstract

Despite the benefits associated with a physically active lifestyle, many older adults are insufficiently active to achieve health gain, and also exhibit decreased activity levels with age. Insufficient physical activity in this population is associated with increased morbidity, mortality and demand on health care services and expenditure. There is a clear need for effective intervention to encourage physical activity in older adults. The aim of this paper is to describe the development and participant evaluation of a randomized controlled trial of TeleWalk, a telephone-based motivational counseling intervention to encourage physical activity in adults aged 65 years and older. Participants (N = 186, mean age 74 ± 6 years) were recruited through their General Practitioner (primary care physician) and randomized to either receive eight telephone counseling sessions and related printed materials over 3 months (intervention group) or participate in outcome assessments only (control group). Intervention group participants were mailed an anonymous evaluation questionnaire on intervention completion. A high response rate was achieved (70%). All respondents (100%) agreed or strongly agreed that a good overall level of service and support was provided, and that the counselor was understanding and supportive. Nearly all respondents agreed or strongly agreed that the service was professional, the counselor advice was helpful and motivating and the information provided was relevant (97, 95 and 89%, respectively). Most (87%) agreed or strongly agreed that the telephone calls encouraged them to be physically active. Among the participants who received printed material, most agreed or strongly agreed that these encouraged them to become or remain active. Findings from this evaluation can be used to inform such interventions and ensure their relevance to community-dwelling older adults.

INTRODUCTION

While the benefits of physical activity are widely extolled for older adults (Ministry of Health, 2003), physical activity participation may decrease with older age (DiPietro, 2001), and many older adults are not sufficiently active for health gain (Taylor et al., 2004). Thus, a need exists for interventions to encourage increased physical activity in older adults.

Home-based interventions can achieve high rates of participation in elderly populations, although the long-term effectiveness of such programs in increasing physical activity levels are unclear, and the effectiveness of using behavioral reinforcement strategies remains equivocal (van der Bij et al., 2002; Ashworth et al., 2005). Meta-analysis of interventions with older adults showed that, individually, neither cognitive nor behavioral modification approaches were associated with increased physical activity (Conn et al., 2002). Nonetheless, a critical review of factors associated with successful physical activity interventions in adults 50 years and older provided evidence for the utility of combining cognitive and behavioral strategies (King et al., 1998). Further, providing ongoing telephone-based supervision may prove effective with older adults (Castro and King, 2002). In terms of physical activity strategies for the general adult population, both telephone-based and print-based delivery of programs may have a modest impact on behavior, and a combination of mediated approaches may be more effective than one approach alone (Marshall et al., 2004). In more general terms, it has been demonstrated that tailoring interventions to individuals, and basing such interventions on individual's stage of change (Prochaska et al., 1992) is effective for changing health behaviors (Zimmerman et al., 2000), including those specific to physical activity of adults (Marcus and Simkin, 1994). In a review paper specific to older adults, King suggested that to encourage participation in physical activity, programs should be uncomplicated, be conducted at a convenient location and with convenient scheduling, be inexpensive and non-competitive, and should promote moderate intensity activities (King, 2001).

A number of studies using telephone support for physical activity in older adults have been carried out. Two studies using telephone counseling failed to show superiority over other activity promotion interventions (Humpel et al., 2004; Ball et al., 2005), probably as they had no usual care control arm making it difficult to identify the true effects of the interventions. Humpel et al. compared a weekly telephone-assisted counseling program and three self-help brochures with brochure provision alone to encourage walking in 399 adults aged 60 years and older (Humpel et al., 2004). At the end of the 3-week intervention both groups reported significant increases in amount of walking for exercise per week. Telephone calls, however, were related to an increased awareness and reading of the printed material. Of those who received the calls, 58% rated the calls as moderately to extremely useful and 42% stated that the calls influenced their walking activity. Ball et al. compared two interventions in increasing walking and other physical activity in 66 adults aged 45–78 years: the first, comprising provision of a pedometer and physical activity log, as well as two instructional newsletters; and the second being the same as the first, with the addition of six telephone calls that were individualized to participants' stage of change and based on motivational interviewing methods (Ball et al., 2005). Again, participants in both groups showed a significant increase in self-reported total physical activity, moderate to vigorous physical activity and walking activity over the 12-week intervention. While activity changes were sustained in both groups for a further 4 weeks, those who received the telephone support maintained slightly higher total physical activity and walking activity than those who did not. Participants most frequently cited pedometer provision as being most helpful, followed by the telephone calls and newsletters. Those who received the telephone calls rated the program as being very or extremely helpful, compared with participants who did not receive the calls (82 and 61%, respectively).

More intensive interventions such as the Community Healthy Activities Model Program for Seniors (CHAMPS II) used individualized support (based on participants' stage of change) to increase self-efficacy and to encourage long-term improvements in physical activity participation in older adults (Stewart et al., 2001). Participants were 164 sedentary adults (average age, 74 years). Information and support was provided through an information evening, individual planning sessions, monthly group workshops, physical activity diaries, telephone counseling and monthly newsletters. At 12 months, intervention group participants exhibited a significantly greater increase in caloric expenditure in both low and moderate intensity activities than participants in the control group. In terms of actual physical activity levels, these increases approximated to an additional 20 min of walking, five times per week. Telephone counseling appears to be a useful component of activity promotion interventions. Further research establishing long-term effectiveness of such programs is needed.

Another important factor in encouraging physical activity participation in older adults is the involvement of primary care physicians. For example, a controlled trial of primary care physician education on the benefits of social and physical activity for older patients found that patients of physicians who received the education intervention increased their walking by an average of 44 min per week more than patients of physicians who did not (Kerse et al., 1999). Another study compared three 12-week interventions to increase the physical activity in 136 inactive older adults aged 50–70 years: a physician initiated physical activity prescription; a physician activity prescription and individualized counseling from an exercise specialist; and a physician activity prescription, exercise specialist counseling and pedometer provision (Armit et al., 2004). The active prescription and counseling group had a higher proportion of active participants than the other groups at 12 weeks, however, by 24 weeks all groups had significantly increased time spent walking and total time in physical activity. The group that received pedometers in addition to the active prescription and counseling had a higher proportion of active participants at 24 weeks than other groups.

A randomized controlled trial of New Zealand's Green Prescription program, a physician initiated active scripting program, was conducted by Elley et al. (Elley et al., 2003). It was found that those who received the physician's activity prescription followed by telephone support for physical activity increased their physical activity by 34 min per week more than the control group. Further, over 12 months, the proportion of participants that was sufficiently active for health gain increased by almost 10%.

In summary, it appears that telephone counseling, primary care physician involvement, motivational interviewing techniques and centering physical activity interventions on individual stage of change are all important in encouraging physical activity participation in older adults. However, while the data to support these interventions are encouraging, there are still important issues that have not been resolved. In particular, since most trials to date have not used true non-treatment control groups, the magnitude of the effect that telephone counseling has compared to no treatment is not clear. In addition, the effects of such counseling on health-related quality of life are unclear.

The present study was designed to investigate the effectiveness of a telephone counseling intervention (TeleWalk) on physical activity (especially walking activity) and health-related quality of life in sedentary older adults recruited through their primary care physician. The purpose of this paper is to describe the development of the TeleWalk intervention, outline the study methods used to evaluate the intervention and to report the findings of the process evaluation of the TeleWalk intervention.

METHODS

Procedures and participants

The TeleWalk study was a randomized controlled trial to investigate the effectiveness of a telephone-based counseling intervention aimed to increase physical activity in sedentary older adults. Participants were recruited with an invitation letter from their primary care physician. Patient lists from three general medical practices in Auckland, New Zealand, were pre-screened by treating physicians. Specifically, individuals for whom walking was contraindicated, or a 20 min phone call would not be possible, were excluded from receiving the invitation letter. Participants who agreed (through a reply-paid return card) to participate were further screened and excluded if they met one or more of the following criteria: (i) had participated in 30 min of physical activity on 5 or more days per week for 6 months or longer; (ii) had participated in two bouts of 20 min of vigorous exercise per week for 6 months or longer; (iii) had a medical history or major health problem that meant walking would be contraindicated; and (iv) would not be living in Auckland, New Zealand, for the next 12 months. This screening was conducted over the telephone by one of the research team who then visited the participant at home to further explain the study and complete the written informed consent process.

Outcome measures were assessed at baseline and 3 months (end of intervention), and then at 6 months and 12 months post-baseline to assess any longer-term effects of the intervention. These included the Auckland Heart Study Physical Activity Questionnaire (Jackson, 1989) and the Short Form-36 Health Survey as a measure of health-related quality of life (Ware et al., 2000). In addition, information on falls and injuries were collected over the 3 month intervention period. The Ministry of Health Regional Ethics Committee approved the study. The 186 participants (63 males and 123 females; mean age 74 ± 6 years) were recruited between June 2003 and March 2004. After enrollment, participants were randomized (by computer-generated random number) to either receive the TeleWalk intervention and outcomes assessments (intervention) or receive assessments only (no-treatment control).

Theoretical framework for the intervention

The transtheoretical model of behavior change (Prochaska et al., 1992) formed the theoretical base from which to understand behavior change processes and inform the TeleWalk intervention development. This approach posits that behavior change is a process whereby individuals progress through various stages of change, and to achieve behavior change, interventions must be tailored to an individual's current stage of change. A review of controlled trials that utilized this model to increase physical activity showed that in the short (≤6 months) and long term (>6 months), 73 and 29% of studies, respectively, were effective in stage progression, improvement in activity level or both (Adams and White, 2003).

Likewise, both motivational interviewing (Miller, 1983) and cognitive–behavioral therapy (Beck et al., 1979) have been successfully employed to change health-related behaviors in adults (Britt et al., 2003). Therefore, these two approaches were integrated to inform the TeleWalk intervention, in terms of how best to facilitate behavior change. Resultant strategies employed included as follows:

  • expressing empathy;

  • increasing knowledge of the benefits of physical activity;

  • increasing awareness of the risks of a sedentary lifestyle;

  • increasing awareness of physical activity opportunities;

  • identifying motivators;

  • problem-solving barriers;

  • recognizing and resolving ambivalence;

  • identifying discrepancies between behavior and goals (cognitive dissonance);

  • improving physical activity self-efficacy;

  • goal setting and tracking using SMART (specific, measurable, achievable, realistic, time-related) goal principals;

  • enlisting social support;

  • using prompts to be active;

  • reinforcement (internal and external rewards); and

  • discussing safe methods to exercise.

As well, discussions around relapse prevention and identifying and problem-solving future barriers to physical activity were included.

Intervention description

Participants in the TeleWalk intervention group received eight telephone calls from a motivational counselor (MO) over a 12 week period. Calls were conducted weekly for the first 4 weeks, and then every 2 weeks for the remaining 8 weeks of the intervention. Mean (± SD) call lengths ranged from 10.2 ± 5.3 (call 6) to 16.5 ± 6.9 (call 1) min. Mean duration of phone calls were highest for the initial phone call, followed by the eighth (final) phone call (14.1 ± 6.2 min), and lastly calls 2–7 ranged on average from 10.2 to 11.8 min each.

Telephone scripts

Flexible telephone scripts were designed for each stage of change of the transtheoretical model of behavior change (Prochaska et al., 1992). This individualized support was based on telephone scripts used in the study of Ball et al. (Ball et al., 2005). These scripts were modified for use with older New Zealand adults, and to ensure the aims of the TeleWalk study were being met. TeleWalk telephone scripts were used as a guide only, providing the counselor with prompts and cognitive–behavioral strategies appropriate to the individual's stage of change (Britt et al., 2003).

Written material and behavioral techniques

Standardized supplementary material was posted to participants in the form of a walking log and TeleWalk pamphlets where appropriate. The walking log was sent to participants only if they indicated interest in receiving a diary to record their physical activity. The log was used as a motivational tool to record goals, track progress and to encourage discussion with the counselor. Three TeleWalk pamphlets were available for participants (see Table 1 for details of contents). Additional information (e.g. local walks, fitness centers and walking groups) was researched and sent out when participants indicated this would encourage them to be physically active.

Table 1:

TeleWalk pamphlet descriptions

Pamphlet title Purpose Components 
Walking is GREAT for you Education Benefits of walking, including those specific to older adults 
  Promoting accumulating 30 min of walking a day, starting with an achievable pace and duration, and gradually increasing these 
  Hints to help sedentary participants start walking 
  Safety tips (e.g. adequate fluid intake, environmental awareness, wearing non-slip shoes) 
Stretch for health Education Benefits of stretching 
 Injury prevention Photos and detailed instructions for four stretches applicable to walking, and physiotherapist approved for use with mobile older adults 
Keep up the great work Motivation SMART goal setting 
 Relapse prevention Cognitive–behavioral strategies to avoid potential relapse 
  Hints to encourage ongoing activity 
  Safety tips 
Pamphlet title Purpose Components 
Walking is GREAT for you Education Benefits of walking, including those specific to older adults 
  Promoting accumulating 30 min of walking a day, starting with an achievable pace and duration, and gradually increasing these 
  Hints to help sedentary participants start walking 
  Safety tips (e.g. adequate fluid intake, environmental awareness, wearing non-slip shoes) 
Stretch for health Education Benefits of stretching 
 Injury prevention Photos and detailed instructions for four stretches applicable to walking, and physiotherapist approved for use with mobile older adults 
Keep up the great work Motivation SMART goal setting 
 Relapse prevention Cognitive–behavioral strategies to avoid potential relapse 
  Hints to encourage ongoing activity 
  Safety tips 

It was essential that the intervention be highly individualized, as participants exhibited variability in walking ability, walking aid use, health status, medication intake, stage of life and general attitude towards physical activity. Poor health status of participants' partners was also a potential barrier in terms of time and commitment for walking, and participation in the intervention in this population. Individuals in this situation required a high degree of flexibility with regards to the timing and duration of phone calls.

EVALUATION

Process evaluation of the TeleWalk intervention

Process evaluation involved seeking participants' subjective evaluation of the TeleWalk intervention components and service provided by the counselor. A participant satisfaction survey was developed by identifying all components of the intervention and forming questions to assess each component. Responses were recorded on a five-point Likert scale that ranged from ‘strongly disagree’ to ‘strongly agree’. The first part of the survey focused on counselor support, which was assessed in terms of counselor advice being helpful and/or relevant, and whether the counselor provided a service that was motivating, understanding, supportive and/or professional. Second, participants were asked whether specific intervention components (telephone calls, walking log and pamphlets) had encouraged them to get, or remain, active. Further comments and feedback were invited, with particular regard to suggestions for improved counselor support and identification of missing intervention components. The survey was pilot-tested to ensure ease of use and appropriate readability, and was then sent by mail to all intervention participants (n = 90) upon completion of the intervention period (3 months). Data analysis for the closed questions comprised summing the number of responses for each of the five points of the Likert scale and calculating percentages based on the total number of responses for that question. For the general comments (open question format), the total number of responses relating to common themes was summed and percentages calculated based on the number of overall respondents (n = 63).

Results of process evaluation

Of the 90 participant satisfaction surveys sent, 63 complete questionnaires were returned (70% response rate). Survey results are outlined in Table 2, and are discussed in more detail below.

Table 2:

TeleWalk intervention participant feedback (N = 63) on the counselor support and effectiveness of the intervention components in encouraging them to get or stay active

 Strongly disagreeaN (%) DisagreeaN (%) NeutralaN (%) AgreeaN (%) Strongly agreeaN (%) Not applicableaN (%) 
Participant evaluation of counselor support 
    The advice given was helpful 0 (0) 0 (0) 3 (5) 28 (44) 32 (51) 0 (0) 
    The information and advice given was relevant 0 (0) 0 (0) 7 (11) 29 (46) 27 (43) 0 (0) 
    The counselor was motivating in terms of getting/staying physically active 0 (0) 0 (0) 3 (5) 19 (30) 41 (65) 0 (0) 
    The counselor was understanding and supportive 0 (0) 0 (0) 0 (0) 16 (25) 47 (75) 0 (0) 
    The service was professional 0 (0) 0 (0) 2 (3) 20 (32) 41 (65) 0 (0) 
    A good overall level of service and support was provided 0 (0) 0 (0) 0 (0) 27 (43) 36 (57) 0 (0) 
Participant evaluation of the effectiveness of intervention components in encouraging them to get or stay active 
    Telephone calls 0 (0) 0 (0) 8 (13) 28 (44) 27 (43) 0 (0) 
    Walking log 0 (0) 4 (6) 9 (14) 25 (40) 17 (27) 8 (13) 
    ‘Benefits of walking’ pamphlet 0 (0) 1 (2) 8 (13) 31 (49) 18 (29) 5 (8) 
    ‘Stretch for health’ pamphlet 0 (0) 2 (3) 3 (5) 32 (51) 21 (33) 5 (8) 
    ‘Keep up the great work’ pamphlet 0 (0) 1 (2) 9 (14) 24 (38) 20 (32) 9 (14) 
 Strongly disagreeaN (%) DisagreeaN (%) NeutralaN (%) AgreeaN (%) Strongly agreeaN (%) Not applicableaN (%) 
Participant evaluation of counselor support 
    The advice given was helpful 0 (0) 0 (0) 3 (5) 28 (44) 32 (51) 0 (0) 
    The information and advice given was relevant 0 (0) 0 (0) 7 (11) 29 (46) 27 (43) 0 (0) 
    The counselor was motivating in terms of getting/staying physically active 0 (0) 0 (0) 3 (5) 19 (30) 41 (65) 0 (0) 
    The counselor was understanding and supportive 0 (0) 0 (0) 0 (0) 16 (25) 47 (75) 0 (0) 
    The service was professional 0 (0) 0 (0) 2 (3) 20 (32) 41 (65) 0 (0) 
    A good overall level of service and support was provided 0 (0) 0 (0) 0 (0) 27 (43) 36 (57) 0 (0) 
Participant evaluation of the effectiveness of intervention components in encouraging them to get or stay active 
    Telephone calls 0 (0) 0 (0) 8 (13) 28 (44) 27 (43) 0 (0) 
    Walking log 0 (0) 4 (6) 9 (14) 25 (40) 17 (27) 8 (13) 
    ‘Benefits of walking’ pamphlet 0 (0) 1 (2) 8 (13) 31 (49) 18 (29) 5 (8) 
    ‘Stretch for health’ pamphlet 0 (0) 2 (3) 3 (5) 32 (51) 21 (33) 5 (8) 
    ‘Keep up the great work’ pamphlet 0 (0) 1 (2) 9 (14) 24 (38) 20 (32) 9 (14) 

aNumber of respondents and percentage of total respondents in parentheses.

Counselor support

All respondents agreed or strongly agreed that the TeleWalk counselor was understanding and supportive, and that a good overall level of service and support was provided. Almost all (97%) of the participants agreed or strongly agreed that the service was professional, and 95% reported that the advice provided was helpful and the counselor was motivating in terms of becoming and remaining physically active. Lastly, 89% of respondents agreed or strongly agreed that the information provided by the counselor was relevant.

Intervention components

Of all mail-out materials, participants were most interested in receiving the ‘Benefits of walking’ and ‘Stretch for health’ pamphlets (92% of participants), followed by the walking log (87%) and the ‘Keep up the great work’ pamphlet (86%). A majority of respondents reported that the telephone calls encouraged them to become or remain active (87% agreed or strongly agreed). Likewise, most of the participants (92%) who received the ‘Stretch for health’ pamphlet either agreed or strongly agreed that the pamphlet motivated them to be physically active. Slightly fewer participants who received the ‘Benefits of walking’ and ‘Keep up the great work’ pamphlets reported that these pamphlets encouraged them to be active (84 and 82%, respectively, agreed or strongly agreed). Of the participants who received the walking log, 77% agreed or strongly agreed that it helped them to get, or remain, physically active.

General comments

Overall, the general comments provided were positive. Future recommendations from participants predominantly featured increased social support, in the form of meeting with other participants of a similar ability (and within the same neighborhood) for walking and other group activities (n = 9; 14%). This social support was with respect to meeting other research participants only, as opposed to attending external, established physical activity groups. Some participants also noted ongoing counselor support as a recommendation for future intervention (n = 2; 3%), and one participant would have preferred to have met face-to-face with the counselor, at least once, for assessment of walking ability (n = 1; 1.6%). Another suggestion was to include objective medical outcome measurements (e.g. heart rate, blood pressure) (n = 3; 4.8%).

DISCUSSION

This is the first randomized controlled trial of extended (eight calls over 12 weeks) telephone-based motivational interviewing to encourage physical activity in a sample of older adults in New Zealand.

The results of the participant evaluation show that we have been successful in developing and delivering a program that was acceptable and had utility for the target group. All elements of the counselor service and support were rated highly. Likewise, all intervention components were perceived by the participants to be important in motivating them to become and/or remain physically active. That the telephone calls were considered helpful is in line with findings from earlier studies (Humpel et al., 2004; Ball et al., 2005). The lower perceived importance of the walking log is in agreement with the Ball et al. findings, and probably owing to the participant burden associated with completing such activity diaries (Ball et al., 2005).

One limitation of these findings is that non-response bias may have influenced outcomes of the participant evaluation. Given the high response rate, however, the authors feel this is unlikely. It is possible that respondents had a positive bias towards evaluating the intervention owing to the relationship developed with the activity counselor. To minimize this bias, the survey began with the sentences: ‘It is important that you share both your positive and negative feedback in this survey, so that we can improve the service we provide to others. Your honesty is appreciated and valued’. Further, participants were reminded that their responses were confidential, and that they could not be identified on the survey.

Future physical activity interventions may benefit from including options for social support such as providing opportunities to meet, and walk with, other intervention participants. There is also potential for increased physician involvement with regards to recording medical outcomes, to improve participants' motivation and to increase their knowledge and understanding of the importance of physical activity. Many participants were undertaking regular medical checkups anyway, but these were not timed in line with the study. Accordingly, longer programs may enable increased interaction with physicians and exercise counselors, including the provision of specialized feedback and follow-up.

This intervention took the basic approach of the transtheoretical model, and integrated the tools of cognitive–behavioral therapy and motivational interviewing to assist the counselor. Such an approach appears worthwhile, at least in terms of participant satisfaction. Whether long-term behavior change was achieved is yet to be established in future analyses; however, the intervention adherence and effectiveness may be reliant on participant satisfaction with the approach and materials.

Consideration of the feasibility and practicalities of administering any intervention is essential. While cost analyses were not conducted for this study, telephone counseling forms an important part of active scripting initiatives such as the Green Prescription program (Elley et al., 2003) in New Zealand. Hence, evaluation of such processes is important. Findings from the Green Prescription have also shown the utility and feasibility of conducting this type of intervention with New Zealand adults, across a range of settings and with a variety of counselors (Elley et al., 2003).

There is a clear need to encourage older adults to become, and remain, sufficiently active for health gain. Telephone counseling, primary care physician involvement, motivational interviewing and basing physical activity interventions on stage of change are important in physical activity interventions for older adults. Additionally, interventions must be cost- and time-effective, and scripts and other intervention materials must be flexible to allow for differing stages of change and physical abilities. Importantly, intervention processes and materials must be acceptable to participants. The TeleWalk intervention was designed to meet these requirements, and the present description and process evaluation of the TeleWalk intervention development provides a useful resource for those wishing to implement such a program. Whether the TeleWalk program was efficacious in increasing physical activity and health-related quality will be reported in due course.

This research was funded by the National Heart Foundation of New Zealand (Grant Number 1017). We thank the primary care physicians involved with the study, and their nursing and administration staff, for the tremendous support in recruiting participants. We also acknowledge and thank researchers from the ‘Get Mobile’ study, in particular Dr Kylie Ball of Deakin University, Australia, and Professor Abby King of Stanford University, USA, for their assistance in the initial development of the TeleWalk intervention scripts.

REFERENCES

Adams
J.
White
M.
Are activity promotion interventions based on the transtheoretical model effective? A critical review
British Journal of Sports Medicine
 , 
2003
, vol. 
37
 (pg. 
106
-
114
)
Armit
C.
Brown
W.
Ritchie
C.
Marshall
A.
Trost
S.
Green
A.
Promoting physical activity to older adults in general practice [Abstract]
Journal of Science and Medicine in Sport
 , 
2004
, vol. 
7
 pg. 
53
 
Ashworth
N.L.
Chad
K.E.
Harrison
E.L.
Reeder
B.A.
Marshall
S.C.
Home versus center based physical activity programs in older adults
The Cochrane Database of Systematic Reviews
 , 
2005
, vol. 
1
  
Art. No.: CD004017.pub2. DOI: 10.1002/14651858.CD004017
Ball
K.
Salmon
J.
Leslie
E.
Owen
N.
King
A.C.
Piloting the feasibility and effectiveness of print- and telephone-mediated interventions for promoting the adoption of physical activity in Australian adults
Journal of Science and Medicine in Sport
 , 
2005
, vol. 
8
 (pg. 
134
-
142
)
Beck
A.T.
Rush
A.J.
Shaw
B.F.
Emery
G.
Cognitive Therapy of Depression
 , 
1979
New York
Guilford Press
Britt
E.
Blampied
N.M.
Hudson
S.M.
Motivational interviewing: a review
Australian Psychologist
 , 
2003
, vol. 
38
 (pg. 
193
-
201
)
Castro
C.M.
King
A.C.
Telephone-assisted counseling for physical activity
Exercise and Sport Sciences Reviews
 , 
2002
, vol. 
30
 (pg. 
64
-
68
)
Conn
V.S.
Valentine
J.C.
Cooper
H.M.
Interventions to increase physical activity among aging adults: a meta-analysis
Annals of Behavioral Medicine
 , 
2002
, vol. 
24
 (pg. 
190
-
200
)
DiPietro
L.
Physical activity in aging: changes in patterns and their relationship to health and function
The Journals of Gerontology
 , 
2001
, vol. 
56A
 (pg. 
13
-
22
)
Elley
C.R.
Kerse
N.
Arroll
B.
Robinson
E.
Effectiveness of counselling patients on physical activity in general practice: cluster randomised controlled trial
British Medical Journal
 , 
2003
, vol. 
326
 (pg. 
793
-
798
)
Humpel
N.
Marshall
A.L.
Iverson
D.
Leslie
E.
Owen
N.
Trial of print and telephone delivered interventions to influence walking
Preventive Medicine
 , 
2004
, vol. 
39
 (pg. 
635
-
641
)
Jackson
R.
The Auckland Heart Study: a case–control study of coronary heart disease
1989
 
Doctoral thesis, University of Auckland, Auckland, New Zealand
Kerse
N.M.
Flicker
L.
Jolley
D.
Arroll
B.
Young
D.
Improving the health behaviours of elderly people: randomised controlled trial of a general practice education programme
British Medical Journal
 , 
1999
, vol. 
319
 (pg. 
683
-
687
)
King
A.C.
Interventions to promote physical activity by older adults
The Journals of Gerontology
 , 
2001
, vol. 
56A
 (pg. 
36
-
46
)
King
A.C.
Rejeski
W.J.
Buchner
D.M.
Physical activity interventions targeting older adults
American Journal of Preventive Medicine
 , 
1998
, vol. 
15
 (pg. 
316
-
333
)
Marcus
B.H.
Simkin
L.R.
The transtheoretical model: applications to exercise behavior
Medicine and Science in Sports and Exercise
 , 
1994
, vol. 
26
 (pg. 
1400
-
1404
)
Marshall
A.L.
Owen
N.
Bauman
A.E.
Mediated approaches for influencing physical activity: update of the evidence on mass media, print, telephone and website delivery of interventions
Journal of Science and Medicine in Sport
 , 
2004
, vol. 
7
 (pg. 
74
-
80
)
Miller
W.R.
Motivational interviewing with problem drinkers
Behavioural Psychotherapy
 , 
1983
, vol. 
11
 (pg. 
147
-
172
)
Ministry of Health
DHB Toolkit: Physical Activity.
 , 
2003
Wellington, New Zealand
Ministry of Health
Prochaska
J.O.
DiClemente
C.C.
Norcross
J.C.
In search of how people change. Applications to addictive behaviours
American Psychologist
 , 
1992
, vol. 
47
 (pg. 
1102
-
1114
)
Stewart
A.L.
Verboncoeur
C.J.
McLellan
B.Y.
Gillis
D.E.
Rush
S.
Mills
K.M.
, et al.  . 
Physical activity outcomes of CHAMPS II: a physical activity promotion program for older adults
The Journals of Gerontology
 , 
2001
, vol. 
56A
 (pg. 
M465
-
M470
)
Taylor
A.H.
Cable
N.T.
Faulkner
G.
Hillsdon
M.
Narici
M.
Van Der Bij
A.K.
Physical activity and older adults: a review of health benefits and the effectiveness of interventions
Journal of Sports Sciences
 , 
2004
, vol. 
22
 (pg. 
703
-
725
)
van der Bij
A.K.
Laurant
M.G H.
Wensing
M.
Effectiveness of physical activity interventions for older adults. A review
American Journal of Preventive Medicine
 , 
2002
, vol. 
22
 (pg. 
120
-
133
)
Ware
J.E.
Kosinski
M.
Gandek
B.
SF-36® Health Survey: Manual and Interpretation Guide
 , 
2000
Lincoln
QualityMetric Incorporated
Zimmerman
G.L.
Olsen
C.G.
Bosworth
M.F.
A ‘stages of change’ approach to helping patients change behavior
American Family Physician
 , 
2000
, vol. 
61
 (pg. 
1409
-
1416
)