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Promoting weight control at the worksite: A pilot program of self-motivation using payroll-based incentives
PREVENTIVE
MEDICINE
14, 187-194 (1985)
Promoting Weight Control at the Worksite: Self-Motivation Using Payroll-Based
A Pilot Program Incentives’
of
ROBERT W. JEFFERY, PH.D.,* JEAN L. FORSTER, PH.D., AND MARY KAYE SNELL, B.A. Division
OfEpidemiology, S.E.,
School of Public Health, University of Minnesota, Stadium Gate 27, Minneapolis, Minnesota 55455
611 Beacon
Street,
Thirty-six individuals participated in a worksite weight-loss program in which the central component was a self-motivation program of biweekly payroll deductions refunded contingent on meeting self-selected weight-loss goals. Half were assigned to early treatment and the remainder to a delayed treatment control group. Nine additional individuals also enrolled at the time of delayed treatment and were included in descriptive analyses of factors associated with weight loss. Results showed low program attrition over 6 months (6%) and mean weight losses (12.3 lb) that are competitive with those obtained in clinical settings. Although not different at baseline, participants in the delayed treatment group lost more than twice as much weight as those in the early treatment condition. This difference was interpreted as either a strong seasonal effect or a critical mass effect related to the proportion of employees at the worksite participating in the program. We conclude that selfmotivation programs for health behavior change using the payroll system as an organization framework offer a promising new methodology for promoting healthful behaviors in work settings. 0 1985 Academic Press, Inc.
INTRODUCTION
Weight control programs at the worksite, along with other health promotion activities, have attracted much recent interest. The reasons are several. (a) Weight control is of great personal interest to many employees and, thus, is an attractive fringe benefit. (b) Successful weight loss may improve company profitability through reduced health-care costs and increased productivity. (c) Worksite programs may be less expensive than similar programs conducted in medical settings. (d) Worksite programs may be more effective than those in other settings because they are better integrated into the normal lives of program participants. (e) Worksite programs may attract individuals in need who would be unwilling or unable to participate in clinical weight control therapy. Although weight control programs are now being offered by many companies, either independently or as part of larger health promotion packages (5), little systematic research has been done to determine how best to structure treatments in this setting. Brownell and Stunkard have reported a series of three weight-loss studies using standard clinical methodologies at the worksite among members of the United Storeworkers Union in New York City (3, 9). Results were less impressive than for similar programs in the clinic. Attrition rates ranged from 34 to ’ Research supported by NIH Grant 5R01-AM267542 * To whom reprint requests should be addressed.
to Dr. Jeffery.
187 0091-7435185 $3.00 Copyright 0 1985 by Academic Press, Inc. All rights of reproduction in any form reserved.
188
JEFFERY,
FORSTER,
AND
SNELL
58%, and weight losses among those completing the programs ranged from 7.3 to 9.0 lb. Nevertheless, it was argued that the programs had a favorable costeffectiveness ratio. Abrams and Follick reported a similar experience among hospital employees in Providence, Rhode Island (1). Among 133 employees, the dropout rate was 48.1% and the average weight loss of program completers was 9.7 lb. On the basis of these four initial studies it appears that direct transfer of clinical methodologies to the worksite often results in diminished effectiveness. Using a novel technology of group competition, Brownell in a more recent study was able to address substantially both the attrition and effectiveness issues (2). Organizing employees into competing groups, either within or across companies, it was found that attrition rates were less than 1% and mean weight losses were more competitive with clinical practice. Brownell reasoned that this method was more effective because it took advantage of structural features of the worksite to enhance participant motivation. The present study was also undertaken to evaluate methods of creating motivation for weight loss in a work setting. The present research group has been exploring the effectiveness of financial contracts in promoting weight loss for several years (6-8). These studies, and those of others (4), indicate that financial incentives are effective in both reducing program attrition and increasing weight loss. Recognizing that worksites have well-developed mechanisms for collecting and disbursing funds, we reasoned that a program of financial incentives might be well suited to an employee weight-loss program. The financial incentives were organized as self-determined weight-loss contracts utilizing the payroll deduction system. Study participants selected their own weight-loss goals and biweekly payroll deductions, return of which, contingent on goals achievement, served to enhance self-motivation. The study sought to evaluate formally the effectiveness of this treatment method. METHODS
Recruitment of Subjects Participants for the program were recruited from among employees of the School of Public Health and several departments of the School of Medicine at the University of Minnesota. Program announcements were distributed via campus mail to 675 employees. Interest was indicated by mailing a tear-off form to the study office. Those indicating interest were scheduled to attend an orientation session. Thirty-six individuals enrolled initially and were assigned at random to early treatment or to delayed treatment control groups. Between the start of the study and the initiation of treatment for the control group (3 months), 9 additional persons requested permission to join the program and were allowed to do so. Thus, the total number of participants was 45, with 36 being used to compare treatment with no treatment. The Weight-Loss
Incentive
Plan
The program required participants period of 6 months. Each completed
to agree to a payroll incentive plan over a a payroll deduction form that authorized a
WORKSITE
WEIGHT-LOSS
PROGRAM
189
fixed amount to be withheld from their semimonthly paycheck. A $5 minimum deduction per pay period was specified, but individuals could select any amount above $5 they thought would be motivating. Participants also selected their own weight reduction goals. Goals could range from 0 lb (i.e., weight maintenance) to a maximum of 24% of initial body weight (1% per week). Semimonthly contract goals were determined by dividing the person’s selected weight-loss goal into 12 equal increments (rounded to the nearest ‘h lb). Participants were instructed to attend a study weigh-in every payday. At that time they were given checks immediately for each increment of weight loss achieved up to and including that period’s increment. In the event that a person lost weight at a rate slower than that specified in the incentive plan or missed a scheduled weigh-in, his payroll deduction money was retained on account pending the results of later weigh-ins. All withheld money could be earned back up until the last weigh-in at the end of 6 months. Money remaining on account after that point was divided equally among those participants who achieved their personal weight-loss goals. Participation in the program was voluntary and free of charge to participants. Individuals could withdraw by submitting revised payroll deduction forms. Participation in all program activities, including weigh-ins and the instructional programs described below, were optional, as were recommended homework assignments to enhance weight management. Instructional Program The study participants were encouraged to attend semimonthly group educational sessions provided at the same time as the weigh-in. All were given both a weight-loss manual and food records for monitoring eating behaviors and calorie intake at home. The manual and the group educational sessions were based closely on a 16-session program used extensively in previous research (7). The approach emphasized gradual changes in dietary composition toward a less calorically dense diet, increase in energy expenditure through moderate-intensity activity such as walking, and systematic modification of social and environmental factors contributing to energy imbalance. Evaluation Strategy Evaluation consisted of a comparison of weight losses and percentages achieving self-selected goals between the early treatment and delayed treatment groups and descriptive analyses of participant characteristics and their relationships to treatment outcomes. In addition, the attractiveness of the program to participants was assessed behaviorally by offering a continuation program and observing reenrollment rates. RESULTS
Table 1 describes baseline characteristics of study participants and 6-month results. Figure 1 graphically displays their weight-loss experience, and Table 2 describes the relationship between participant characteristics and weight loss. Since the only formal requirement of the program was participation in the payroll incentive plan, treatment attrition was defined in terms of whether or not
190
JEFFERY,
FORSTER,
AKD
TABLE
CHARACTERISTICS
BASELINE
SNELL
I
AND 6MOYTH TIWATMENT
RESULTS GROUPS~
IN TREATMENT
AND DELAYED
Delayed treatment
Treatment
N
I8
I8
% Female
88.9
83.3
category % Faculty
22.2
o/c Administrative/technical o/c Clerical
38.9 38.9
22.2 50.0
Job
Age Weight at start % Overweight Incentive Weight-loss % Choosing Total weight
’ Two outcome
of intervention at start of intervention
size goal
(lb)
program reenrollmentb loss (Ib)b
% Achieving ” Means and in parentheses.
42.7 178.2 36.5
weight standard
participants values have
goalh deviations
initially randomized an N of 16.
27.8 (9.6) (47.6) (31.8)
$9.39 22.0
(5.5) (13.3)
50.0 8.1
(14.0)
33.0 are
presented to delayed
for
(8.7) (43.0) (36.7) (5.9)
24.8 75.0 17.0
(14.2) (I 1.7)
56.3
continuous treatment
42.1 178.9 36.8 $I 1.47
variables. were
lost
Standard prior
deviations
to intervention.
are Thus.
individuals continued participation in this feature of the program. Using this criterion, 34 of the 36 individuals originally randomized to the study (94%) completed the program. All 9 of the postrandomization enrollees also completed 6 months of participation. Both dropouts were from the delayed treatment group and occurred before the weight-loss phase began. One person withdrew because their employment with the university was terminated. A second withdrew for unknown reasons. Using a more conservative definition of dropping out (poor attendance at weigh-ins), five participants (I 1.6%) attended fewer than half the weigh-ins. Weight losses observed in the study were encouraging. Mean weight loss across the 6-month program period for the 34 individuals randomized was 12.3 lb. Fortyfour percent reached their weight-loss goals. This compares favorably with clinical programs of considerably greater cost. Willingness to reenroll for a second weight program was used as a measure of the popularity of the treatment among participants. Sixty-two percent of those initially randomized sought to continue their participation in the project, with new weight-loss goals and the option of changing the payroll deduction amount. Direct comparison of the treatment and delayed treatment conditions (Fig. I) showed the treatment group lost a significant amount of weight (4.6 lb) compared with the delayed treatment group (2.7~lb gain) during the 3-month delay period, F(1.34) = 11.8, P < 0.005. Comparing the total weight losses for the two groups over 6 months showed the delayed treatment condition to have significantly superior results (g.l- vs 17.0~lb loss); F(1,32) = 6.4, P < 0.025). Possible reasons for this difference are discussed more fully below, but it should be noted here
WORKSITE
WEIGHT-LOSS
191
PROGRAM
TABLE 2 WEIGHT
Loss
AND
REACHING GOAL AS A FUNCTION PARTICIPANT CHARACTERISTICS”
PERCENTAGES
OF SELECTED
Pounds lost
Age
N
Mean
SD
% Reaching goal
22 21
11.5 14.4
14.3 12.5
NS
31.8 47.6
9 19 15
18.2 14.9 7.1
11.6 14.5 11.2
NS
33.3 52.6 26.7
NS
Overweight at start of intervention <20% 14 20-50% 16 >50% 13
10.4 9.0 20.4
9.8 12.9 14.7
F(2,40) = 3.09 P < 0.10
64.3 25.0 30. I
NS
Incentive choice <$lO $10 >$I0
16 13 14
9.3 10.5 19.3
10.7 9.8 16.9
NS
43.8 30.1 42.9
NS
Weight (20 a20 230
17 11 1.5
8.6 13.1 17.6
7.8 12.9 17.3
NS
52.9 36.4 26.7
NS
Weigh-ins attended <7 7-10 110
9 15 19
- 1.6 14.4 18.6
7.2 13.9 10.3
F(2,40) = 9.47 P < 0.001
0 33.3 63.2
Reenrollment status Reenrolled Terminated Total
25 18 43
17.9 6.0 12.9
13.3 10.5 13.6
F(1,4l) = 9.39 P < 0.005
48.0 27.8 39.5
<40 Years >40 Years Job category Faculty Professional/technical Secretary/clerical
loss goal lb < 30 lb lb
NS
x2(2) = 6.44 P < 0.05
NS
0 Data from nine persons who requested entry to the program after initial randomization are included in these statistics. Although the sample size would be smaller, the direction and magnitude of observed relationships are the same with or without these inclusions.
that it was not due to differences between groups in baseline characteristics, the size of participant weight-loss goals, the size of the incentives chosen, or attendance at treatment weigh-ins. As shown in Table 2, weight losses in this program were significantly related only to attendance at weigh-ins. Percentage overweight at baseline, the size of the incentives selected, and the size of participant weight-loss goals were all positively associated with performance, though not significantly so with this sample size. Rates of attainment of personal goals were higher among those who were less overweight and who chose lower goals, but again not significantly so. Interest in continuing in the program beyond the initial 6-month period was also related to initial performance. Those choosing to reenroll for continued weight
192
JEFFERY,
FORSTER,
0-0
Early Treatment
‘--*
Delayed
October 1983
January 1984
AND SNELL
“\
Treatment
April 1984
‘b
July 1984
FIG. 1. Weight changes over time in early treatment and delayed treatment groups.
loss or maintenance were nearly three times as successful on the average than those who chose not to continue their participation. DISCUSSION
Because this research was limited in scope, the results must be considered with appropriate caution. Since a control group with educational content, but without financial incentives, was not included in the design, the unique contribution of this element of the program cannot be evaluated. The total sample size was also relatively small, and the employee group was not representative of those in many other work settings. Clearly, a definitive test of the generalizability of the program requires extension and replication. With the above caveats in mind, the principal objective of this pilot study was to determine whether the previously shown success of financial incentives in motivating weight loss could be transferred to a worksite setting via payroll deduction mechanisms already in place. The answer was largely affirmative. Program attrition, which has been a major problem in previous worksite studies, was exceptionally low-lower in fact, than that seen in most clinical programs (10). Observed weight losses were also competitive with those observed in clinical programs. The weight losses were all the more impressive given that no restrictions were placed on entry weight or weight goals. Indeed, two of the program’s participants had goals of 0 loss, and 13 chose goals under 15 lb. An additional point in favor of this type of program is its practicality. Since program costs are borne by participants, it could be implemented in work settings even when management is unable or unwilling to make financial contributions to health promotion activities. The flexibility in dollar commitment, goals, and participation requirements should also appeal to diverse employee needs. Overall, we view these pilot results as additional support for the argument that effective worksite programs should capitalize on the unique structure of this environment to create motivation
WORKSITE
WEIGHT-LOSS
PROGRAM
193
for sustained effort toward behavior change. Additional research on this and related concepts is highly recommended. The superior performance of the delayed treatment group compared with the early treatment group in this study merits additional discussion. Those in the delayed treatment group lost more than twice as much weight as those treated in an identical program beginning 3 months earlier. Several factors may have contributed to this result. The first 3 months of the early treatment took place during the late fall and winter months, whereas the delayed treatment began in early January. Thus, it is possible that there was a seasonal or holiday effect accounting for some of the difference. Another possible contributor may be that the 3-month delay helped those in the delayed treatment group by allowing more time to prepare for their weight-loss effort. A third possibility is that treatment personnel were more efficient in the second application of the same procedures. Finally, it is possible that the social support system of the worksite was better activated for the second treatment series than for the first due to greater overall employee involvement. The employee base for this project was about 675 individuals. When only 18 (3%) of these were in treatment, it may have been that those in the program rarely interacted with each other. When the second group began treatment, however, more than twice as many individuals, 7% of the total work force and perhaps as many as 25% of overweight employees were involved. This might have created a higher level of mutual interaction and support among the program participants. The relationship between the number of people involved in a health promotion activity and the size of the population base from which they are drawn may deserve special attention as worksite health promotion methodologies develop. The predictors of weight loss in this study were similar to those observed in other studies, although most did not reach significance due to small sample size. Individuals with higher initial weight, larger weight-loss goals, better attendance at treatment sessions, and with higher motivation as measured by self-selected incentives tended to lose more weight. Also similar to other observations, continuing interest in program participation was related to initial success. Although these findings are of interest, we do not believe that they imply a need to be more restrictive in defining participant or program characteristics. For a program to be successful at the worksite, it should appeal to a wide range of persons, those with small and large amounts of weight to lose, those with time to devote to treatment activities and those without, and those with modest and great motivation to change. Indeed, restricting participation to persons “most likely to succeed” might be counterproductive (rather than cost-effective) by undermining the collective effort. Overall, we view this pilot study as a very successful initial effort to apply a payroll-based self-motivation feature to weight-loss programs at the worksite. The data suggest that this technique may have the potential to overcome some problems associated with early attempts to do worksite weight-loss programs, and we are optimistic about future applications. Although handling accounting for monetary deposits and refunds in any system is not without cost, our experience suggests it is feasible in the work setting. Advantages are that the procedure is
194
JEFFERY,
FORSTER,
AND SNELL
suitable for weight maintenance as well as weight loss, it could be adapted easily to behavior change objectives in addition to weight loss, and, because payroll dispersal is a fundamental and continuing part of employment settings, it would seem to have high potential both for generalizability across sites and extension through time within the same site. REFERENCES 1. Abrams, D. B., and Follick, M. J. Behavioral weight loss intervention at the worksite: Feasibility and maintenance. J. Constrtt. C/in. PsychoL 51, 226-233 (1983). 2. Brownell, K. D., Cohen, R. Y., Stunkard, A. J., Felix, M. R. J., and Cooley, N. B. Weight loss competitions at the worksite: Impact on weight, morale, and cost-effectiveness. Amer. J. Public Health, in press. 3. Brownell, K. D., Stunkard, A. J., and McKeon, P. E. Weight reduction at the work site: A promise partially fulfilled. Amer. J. Psychiatry, in press. 4. Follick, M. J., Fowler, J. L., and Brown, R. A. Attrition in worksite weight-loss interventions: The effects of an incentive procedure. f. Cons&. C/in. Psycho/. 52, 139- 140 (1984). 5. Foreyt, J. P., Scott, L. W., and Gotto, A. M. Weight control and nutrition education programs in occupational settings. Public Health Rep. 95, 127-136 (1980). 6. Jeffery, R. W., Bjomson-Benson, W. M., Rosenthal, B. S., Kurth, C. L., and Dunn, M. M. Effectiveness of monetary contracts with two repayment schedules on weight reduction in men and women from self-referred and population samples. Behav. Ther. 15, 273-279 (1984). 7. Jeffery, R. W., Gerber, W. M., Rosenthal, B. S., and Lindquist, R. A. Monetary contracts in weight control: Effectiveness of group and individual contracts of varying size. J. Consul. C/in. Psychol. 51, 242-248 (1983). 8. Jeffery, R. W., Thompson, P. D., and Wing, R. R. Effects on weight reduction of strong monetary contracts for calorie restriction or weight loss. Behuv. Res. Ther. 16, 363-369 (1978). 9. Stunkard, A. J., and Brownell, K. D. Work-site treatment for obesity. Amer. J. Psychiatry 137, 2 (1980). 10. Wing, R. R., and Jeffery, R. W. Sample size in clinical outcome research: The case of behavioral weight control. Behav. Ther. 15, 550-556 (1984).
MEDICINE
14, 187-194 (1985)
Promoting Weight Control at the Worksite: Self-Motivation Using Payroll-Based
A Pilot Program Incentives’
of
ROBERT W. JEFFERY, PH.D.,* JEAN L. FORSTER, PH.D., AND MARY KAYE SNELL, B.A. Division
OfEpidemiology, S.E.,
School of Public Health, University of Minnesota, Stadium Gate 27, Minneapolis, Minnesota 55455
611 Beacon
Street,
Thirty-six individuals participated in a worksite weight-loss program in which the central component was a self-motivation program of biweekly payroll deductions refunded contingent on meeting self-selected weight-loss goals. Half were assigned to early treatment and the remainder to a delayed treatment control group. Nine additional individuals also enrolled at the time of delayed treatment and were included in descriptive analyses of factors associated with weight loss. Results showed low program attrition over 6 months (6%) and mean weight losses (12.3 lb) that are competitive with those obtained in clinical settings. Although not different at baseline, participants in the delayed treatment group lost more than twice as much weight as those in the early treatment condition. This difference was interpreted as either a strong seasonal effect or a critical mass effect related to the proportion of employees at the worksite participating in the program. We conclude that selfmotivation programs for health behavior change using the payroll system as an organization framework offer a promising new methodology for promoting healthful behaviors in work settings. 0 1985 Academic Press, Inc.
INTRODUCTION
Weight control programs at the worksite, along with other health promotion activities, have attracted much recent interest. The reasons are several. (a) Weight control is of great personal interest to many employees and, thus, is an attractive fringe benefit. (b) Successful weight loss may improve company profitability through reduced health-care costs and increased productivity. (c) Worksite programs may be less expensive than similar programs conducted in medical settings. (d) Worksite programs may be more effective than those in other settings because they are better integrated into the normal lives of program participants. (e) Worksite programs may attract individuals in need who would be unwilling or unable to participate in clinical weight control therapy. Although weight control programs are now being offered by many companies, either independently or as part of larger health promotion packages (5), little systematic research has been done to determine how best to structure treatments in this setting. Brownell and Stunkard have reported a series of three weight-loss studies using standard clinical methodologies at the worksite among members of the United Storeworkers Union in New York City (3, 9). Results were less impressive than for similar programs in the clinic. Attrition rates ranged from 34 to ’ Research supported by NIH Grant 5R01-AM267542 * To whom reprint requests should be addressed.
to Dr. Jeffery.
187 0091-7435185 $3.00 Copyright 0 1985 by Academic Press, Inc. All rights of reproduction in any form reserved.
188
JEFFERY,
FORSTER,
AND
SNELL
58%, and weight losses among those completing the programs ranged from 7.3 to 9.0 lb. Nevertheless, it was argued that the programs had a favorable costeffectiveness ratio. Abrams and Follick reported a similar experience among hospital employees in Providence, Rhode Island (1). Among 133 employees, the dropout rate was 48.1% and the average weight loss of program completers was 9.7 lb. On the basis of these four initial studies it appears that direct transfer of clinical methodologies to the worksite often results in diminished effectiveness. Using a novel technology of group competition, Brownell in a more recent study was able to address substantially both the attrition and effectiveness issues (2). Organizing employees into competing groups, either within or across companies, it was found that attrition rates were less than 1% and mean weight losses were more competitive with clinical practice. Brownell reasoned that this method was more effective because it took advantage of structural features of the worksite to enhance participant motivation. The present study was also undertaken to evaluate methods of creating motivation for weight loss in a work setting. The present research group has been exploring the effectiveness of financial contracts in promoting weight loss for several years (6-8). These studies, and those of others (4), indicate that financial incentives are effective in both reducing program attrition and increasing weight loss. Recognizing that worksites have well-developed mechanisms for collecting and disbursing funds, we reasoned that a program of financial incentives might be well suited to an employee weight-loss program. The financial incentives were organized as self-determined weight-loss contracts utilizing the payroll deduction system. Study participants selected their own weight-loss goals and biweekly payroll deductions, return of which, contingent on goals achievement, served to enhance self-motivation. The study sought to evaluate formally the effectiveness of this treatment method. METHODS
Recruitment of Subjects Participants for the program were recruited from among employees of the School of Public Health and several departments of the School of Medicine at the University of Minnesota. Program announcements were distributed via campus mail to 675 employees. Interest was indicated by mailing a tear-off form to the study office. Those indicating interest were scheduled to attend an orientation session. Thirty-six individuals enrolled initially and were assigned at random to early treatment or to delayed treatment control groups. Between the start of the study and the initiation of treatment for the control group (3 months), 9 additional persons requested permission to join the program and were allowed to do so. Thus, the total number of participants was 45, with 36 being used to compare treatment with no treatment. The Weight-Loss
Incentive
Plan
The program required participants period of 6 months. Each completed
to agree to a payroll incentive plan over a a payroll deduction form that authorized a
WORKSITE
WEIGHT-LOSS
PROGRAM
189
fixed amount to be withheld from their semimonthly paycheck. A $5 minimum deduction per pay period was specified, but individuals could select any amount above $5 they thought would be motivating. Participants also selected their own weight reduction goals. Goals could range from 0 lb (i.e., weight maintenance) to a maximum of 24% of initial body weight (1% per week). Semimonthly contract goals were determined by dividing the person’s selected weight-loss goal into 12 equal increments (rounded to the nearest ‘h lb). Participants were instructed to attend a study weigh-in every payday. At that time they were given checks immediately for each increment of weight loss achieved up to and including that period’s increment. In the event that a person lost weight at a rate slower than that specified in the incentive plan or missed a scheduled weigh-in, his payroll deduction money was retained on account pending the results of later weigh-ins. All withheld money could be earned back up until the last weigh-in at the end of 6 months. Money remaining on account after that point was divided equally among those participants who achieved their personal weight-loss goals. Participation in the program was voluntary and free of charge to participants. Individuals could withdraw by submitting revised payroll deduction forms. Participation in all program activities, including weigh-ins and the instructional programs described below, were optional, as were recommended homework assignments to enhance weight management. Instructional Program The study participants were encouraged to attend semimonthly group educational sessions provided at the same time as the weigh-in. All were given both a weight-loss manual and food records for monitoring eating behaviors and calorie intake at home. The manual and the group educational sessions were based closely on a 16-session program used extensively in previous research (7). The approach emphasized gradual changes in dietary composition toward a less calorically dense diet, increase in energy expenditure through moderate-intensity activity such as walking, and systematic modification of social and environmental factors contributing to energy imbalance. Evaluation Strategy Evaluation consisted of a comparison of weight losses and percentages achieving self-selected goals between the early treatment and delayed treatment groups and descriptive analyses of participant characteristics and their relationships to treatment outcomes. In addition, the attractiveness of the program to participants was assessed behaviorally by offering a continuation program and observing reenrollment rates. RESULTS
Table 1 describes baseline characteristics of study participants and 6-month results. Figure 1 graphically displays their weight-loss experience, and Table 2 describes the relationship between participant characteristics and weight loss. Since the only formal requirement of the program was participation in the payroll incentive plan, treatment attrition was defined in terms of whether or not
190
JEFFERY,
FORSTER,
AKD
TABLE
CHARACTERISTICS
BASELINE
SNELL
I
AND 6MOYTH TIWATMENT
RESULTS GROUPS~
IN TREATMENT
AND DELAYED
Delayed treatment
Treatment
N
I8
I8
% Female
88.9
83.3
category % Faculty
22.2
o/c Administrative/technical o/c Clerical
38.9 38.9
22.2 50.0
Job
Age Weight at start % Overweight Incentive Weight-loss % Choosing Total weight
’ Two outcome
of intervention at start of intervention
size goal
(lb)
program reenrollmentb loss (Ib)b
% Achieving ” Means and in parentheses.
42.7 178.2 36.5
weight standard
participants values have
goalh deviations
initially randomized an N of 16.
27.8 (9.6) (47.6) (31.8)
$9.39 22.0
(5.5) (13.3)
50.0 8.1
(14.0)
33.0 are
presented to delayed
for
(8.7) (43.0) (36.7) (5.9)
24.8 75.0 17.0
(14.2) (I 1.7)
56.3
continuous treatment
42.1 178.9 36.8 $I 1.47
variables. were
lost
Standard prior
deviations
to intervention.
are Thus.
individuals continued participation in this feature of the program. Using this criterion, 34 of the 36 individuals originally randomized to the study (94%) completed the program. All 9 of the postrandomization enrollees also completed 6 months of participation. Both dropouts were from the delayed treatment group and occurred before the weight-loss phase began. One person withdrew because their employment with the university was terminated. A second withdrew for unknown reasons. Using a more conservative definition of dropping out (poor attendance at weigh-ins), five participants (I 1.6%) attended fewer than half the weigh-ins. Weight losses observed in the study were encouraging. Mean weight loss across the 6-month program period for the 34 individuals randomized was 12.3 lb. Fortyfour percent reached their weight-loss goals. This compares favorably with clinical programs of considerably greater cost. Willingness to reenroll for a second weight program was used as a measure of the popularity of the treatment among participants. Sixty-two percent of those initially randomized sought to continue their participation in the project, with new weight-loss goals and the option of changing the payroll deduction amount. Direct comparison of the treatment and delayed treatment conditions (Fig. I) showed the treatment group lost a significant amount of weight (4.6 lb) compared with the delayed treatment group (2.7~lb gain) during the 3-month delay period, F(1.34) = 11.8, P < 0.005. Comparing the total weight losses for the two groups over 6 months showed the delayed treatment condition to have significantly superior results (g.l- vs 17.0~lb loss); F(1,32) = 6.4, P < 0.025). Possible reasons for this difference are discussed more fully below, but it should be noted here
WORKSITE
WEIGHT-LOSS
191
PROGRAM
TABLE 2 WEIGHT
Loss
AND
REACHING GOAL AS A FUNCTION PARTICIPANT CHARACTERISTICS”
PERCENTAGES
OF SELECTED
Pounds lost
Age
N
Mean
SD
% Reaching goal
22 21
11.5 14.4
14.3 12.5
NS
31.8 47.6
9 19 15
18.2 14.9 7.1
11.6 14.5 11.2
NS
33.3 52.6 26.7
NS
Overweight at start of intervention <20% 14 20-50% 16 >50% 13
10.4 9.0 20.4
9.8 12.9 14.7
F(2,40) = 3.09 P < 0.10
64.3 25.0 30. I
NS
Incentive choice <$lO $10 >$I0
16 13 14
9.3 10.5 19.3
10.7 9.8 16.9
NS
43.8 30.1 42.9
NS
Weight (20 a20 230
17 11 1.5
8.6 13.1 17.6
7.8 12.9 17.3
NS
52.9 36.4 26.7
NS
Weigh-ins attended <7 7-10 110
9 15 19
- 1.6 14.4 18.6
7.2 13.9 10.3
F(2,40) = 9.47 P < 0.001
0 33.3 63.2
Reenrollment status Reenrolled Terminated Total
25 18 43
17.9 6.0 12.9
13.3 10.5 13.6
F(1,4l) = 9.39 P < 0.005
48.0 27.8 39.5
<40 Years >40 Years Job category Faculty Professional/technical Secretary/clerical
loss goal lb < 30 lb lb
NS
x2(2) = 6.44 P < 0.05
NS
0 Data from nine persons who requested entry to the program after initial randomization are included in these statistics. Although the sample size would be smaller, the direction and magnitude of observed relationships are the same with or without these inclusions.
that it was not due to differences between groups in baseline characteristics, the size of participant weight-loss goals, the size of the incentives chosen, or attendance at treatment weigh-ins. As shown in Table 2, weight losses in this program were significantly related only to attendance at weigh-ins. Percentage overweight at baseline, the size of the incentives selected, and the size of participant weight-loss goals were all positively associated with performance, though not significantly so with this sample size. Rates of attainment of personal goals were higher among those who were less overweight and who chose lower goals, but again not significantly so. Interest in continuing in the program beyond the initial 6-month period was also related to initial performance. Those choosing to reenroll for continued weight
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0-0
Early Treatment
‘--*
Delayed
October 1983
January 1984
AND SNELL
“\
Treatment
April 1984
‘b
July 1984
FIG. 1. Weight changes over time in early treatment and delayed treatment groups.
loss or maintenance were nearly three times as successful on the average than those who chose not to continue their participation. DISCUSSION
Because this research was limited in scope, the results must be considered with appropriate caution. Since a control group with educational content, but without financial incentives, was not included in the design, the unique contribution of this element of the program cannot be evaluated. The total sample size was also relatively small, and the employee group was not representative of those in many other work settings. Clearly, a definitive test of the generalizability of the program requires extension and replication. With the above caveats in mind, the principal objective of this pilot study was to determine whether the previously shown success of financial incentives in motivating weight loss could be transferred to a worksite setting via payroll deduction mechanisms already in place. The answer was largely affirmative. Program attrition, which has been a major problem in previous worksite studies, was exceptionally low-lower in fact, than that seen in most clinical programs (10). Observed weight losses were also competitive with those observed in clinical programs. The weight losses were all the more impressive given that no restrictions were placed on entry weight or weight goals. Indeed, two of the program’s participants had goals of 0 loss, and 13 chose goals under 15 lb. An additional point in favor of this type of program is its practicality. Since program costs are borne by participants, it could be implemented in work settings even when management is unable or unwilling to make financial contributions to health promotion activities. The flexibility in dollar commitment, goals, and participation requirements should also appeal to diverse employee needs. Overall, we view these pilot results as additional support for the argument that effective worksite programs should capitalize on the unique structure of this environment to create motivation
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for sustained effort toward behavior change. Additional research on this and related concepts is highly recommended. The superior performance of the delayed treatment group compared with the early treatment group in this study merits additional discussion. Those in the delayed treatment group lost more than twice as much weight as those treated in an identical program beginning 3 months earlier. Several factors may have contributed to this result. The first 3 months of the early treatment took place during the late fall and winter months, whereas the delayed treatment began in early January. Thus, it is possible that there was a seasonal or holiday effect accounting for some of the difference. Another possible contributor may be that the 3-month delay helped those in the delayed treatment group by allowing more time to prepare for their weight-loss effort. A third possibility is that treatment personnel were more efficient in the second application of the same procedures. Finally, it is possible that the social support system of the worksite was better activated for the second treatment series than for the first due to greater overall employee involvement. The employee base for this project was about 675 individuals. When only 18 (3%) of these were in treatment, it may have been that those in the program rarely interacted with each other. When the second group began treatment, however, more than twice as many individuals, 7% of the total work force and perhaps as many as 25% of overweight employees were involved. This might have created a higher level of mutual interaction and support among the program participants. The relationship between the number of people involved in a health promotion activity and the size of the population base from which they are drawn may deserve special attention as worksite health promotion methodologies develop. The predictors of weight loss in this study were similar to those observed in other studies, although most did not reach significance due to small sample size. Individuals with higher initial weight, larger weight-loss goals, better attendance at treatment sessions, and with higher motivation as measured by self-selected incentives tended to lose more weight. Also similar to other observations, continuing interest in program participation was related to initial success. Although these findings are of interest, we do not believe that they imply a need to be more restrictive in defining participant or program characteristics. For a program to be successful at the worksite, it should appeal to a wide range of persons, those with small and large amounts of weight to lose, those with time to devote to treatment activities and those without, and those with modest and great motivation to change. Indeed, restricting participation to persons “most likely to succeed” might be counterproductive (rather than cost-effective) by undermining the collective effort. Overall, we view this pilot study as a very successful initial effort to apply a payroll-based self-motivation feature to weight-loss programs at the worksite. The data suggest that this technique may have the potential to overcome some problems associated with early attempts to do worksite weight-loss programs, and we are optimistic about future applications. Although handling accounting for monetary deposits and refunds in any system is not without cost, our experience suggests it is feasible in the work setting. Advantages are that the procedure is
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suitable for weight maintenance as well as weight loss, it could be adapted easily to behavior change objectives in addition to weight loss, and, because payroll dispersal is a fundamental and continuing part of employment settings, it would seem to have high potential both for generalizability across sites and extension through time within the same site. REFERENCES 1. Abrams, D. B., and Follick, M. J. Behavioral weight loss intervention at the worksite: Feasibility and maintenance. J. Constrtt. C/in. PsychoL 51, 226-233 (1983). 2. Brownell, K. D., Cohen, R. Y., Stunkard, A. J., Felix, M. R. J., and Cooley, N. B. Weight loss competitions at the worksite: Impact on weight, morale, and cost-effectiveness. Amer. J. Public Health, in press. 3. Brownell, K. D., Stunkard, A. J., and McKeon, P. E. Weight reduction at the work site: A promise partially fulfilled. Amer. J. Psychiatry, in press. 4. Follick, M. J., Fowler, J. L., and Brown, R. A. Attrition in worksite weight-loss interventions: The effects of an incentive procedure. f. Cons&. C/in. Psycho/. 52, 139- 140 (1984). 5. Foreyt, J. P., Scott, L. W., and Gotto, A. M. Weight control and nutrition education programs in occupational settings. Public Health Rep. 95, 127-136 (1980). 6. Jeffery, R. W., Bjomson-Benson, W. M., Rosenthal, B. S., Kurth, C. L., and Dunn, M. M. Effectiveness of monetary contracts with two repayment schedules on weight reduction in men and women from self-referred and population samples. Behav. Ther. 15, 273-279 (1984). 7. Jeffery, R. W., Gerber, W. M., Rosenthal, B. S., and Lindquist, R. A. Monetary contracts in weight control: Effectiveness of group and individual contracts of varying size. J. Consul. C/in. Psychol. 51, 242-248 (1983). 8. Jeffery, R. W., Thompson, P. D., and Wing, R. R. Effects on weight reduction of strong monetary contracts for calorie restriction or weight loss. Behuv. Res. Ther. 16, 363-369 (1978). 9. Stunkard, A. J., and Brownell, K. D. Work-site treatment for obesity. Amer. J. Psychiatry 137, 2 (1980). 10. Wing, R. R., and Jeffery, R. W. Sample size in clinical outcome research: The case of behavioral weight control. Behav. Ther. 15, 550-556 (1984).