Study design
We conducted a 6-month randomized controlled trial of three different moderate-intensity training protocols among older adults living in long-term care facilities, i.e. homes for the aged with services ranging from independent living to skilled nursing. The primary objective of the trial was to study the effects of three different exercise protocols on physical functioning, quality of life, vitality, and depression. In this report we describe the effects on quality of life, vitality and depression. In each of the six homes, subjects were randomly assigned to one of the three exercise conditions or the control condition, an 'educational' program. The random allocation sequence was generated by computer by two independent students, who also assigned participants to their group. The nine couples were randomized together. Random assignment took place after completion of baseline measurements. After the 6-month trial all study participants were allowed to continue either one of the programs as desired. The VU University medical ethics committee has approved the study protocol.
Study population
Participants of the study were living in six residential and extended care facilities in the North-Western part of The Netherlands (i.e. West-Friesland). In each home all residents were invited to informative meetings organized in the homes. At these informative meetings the design of the study and the interventions were explained in detail. Easy accessibility to the exercise programs and the possibility of voluntary withdrawal from the study were emphasized. The information was also available in brochures for the people to take home. At the end of the meeting, subjects received a form on which they could assert whether they were interested in the study. Those interested in study participation were screened for eligibility based on the following inclusion criteria: 1) aged 65 or older; 2) living in a nursing home or residential care facility; 3) able to walk six meters or more (with or without a walking aid); 4) able to comprehend the study procedures; 5) no medical contraindication for study participation; 6) no rapidly progressive or terminal illness; 7) and not moving away from the home within the six months intervention period (5 and 6 were evaluated by their general practitioner). Informed consent was obtained from all subjects.
Interventions
Strength training
The strength training program was performed twice a week during 6 months in groups of 5 to 7 participants directed by a trained physical therapist and an assistant. In the first 2 weeks, participants were familiarized with the equipment and the technique of the exercises by exercising with minimal resistance. The following weeks, resistance increased until 2 sets of 8–12 repetitions were possible. Resistance was to be increased after the participant could complete 2 sets of 12 repetitions for 2 consecutive sessions. As a warm-up, each exercise was first performed 10–20 repetitions with minimal resistance. Progression was monitored with exercise logs filled out by the supervising physical therapist and assistant. The five exercises were leg press, lattisimus pulldown, biceps curl and triceps press on TechnoGym equipment, and heel raises with dumbbells (1 to 5 kg each), ankle and/or wrist weights (1 and 2 kg per pair). For the heel raises the number of repetitions were increased if the subjects could lift the maximum weight (2× 5 kg dumbbells + 2× 2 kg ankle weights). Sessions lasted 45–60 minutes and closed with stretching exercises. The program was designed to improve muscle strength of major muscle groups of both upper and lower body, important for functional performance on common daily activities.
All-round functional training
The all-round, functional training program was performed twice a week during 6 months in groups of 7–15 participants, directed by a trained physical therapist and an assistant. The first week was to familiarize participants with the technique of the exercises. All classes started with 5–10 minutes of warm-up activities: walking (whenever possible), exercise-to-music routines, becoming familiar with the equipment. This was followed by 30–35 minutes of skills training in game-like and cooperative activities, such as throwing and catching a ball while standing up and sitting down on a chair, musical chairs and team pursuit races. The cool-down period (5–10 min) consisted of stretching and relaxation activities (e.g. finger and wrist rolls, shoulder rolls, reaching, leg stretches). All exercises could be adjusted to the individual mobility level. The intensity was gradually increased: the number of repetitions increased, exercises were performed more often standing up straight and the use of wrist and ankle weights (1 and 2 kg per pair) was stimulated. The program was designed to improve muscle strength, speed, endurance, coordination and flexibility to improve functional performance of common daily activities. An emphasis was placed on skills training, meaning that the specific activities required for independence in daily activities were practiced. The design and theoretical background of the all-round, functional training program are described in detail elsewhere [7].
Combination
Subjects in the combination group performed once weekly a complete strength training session and once weekly a complete functional training session.
All three exercise programs were directed by physical therapists who were already working in the homes and thus familiar with working with the study population. The physical therapists were trained by the primary researcher (MCAP). To encourage standardization, the training protocols were extensively described in a manual and the all-round, functional training was illustrated on an instructional videotape. The assistants were either volunteers or students.
Control program
The control program was designed to provide attention, social interaction and was meant to be a 'placebo' intervention. Participants were told that they were assigned to an 'educational' program (i.e. group discussions about topics of interest to older people such as history of the 20th century, music, relaxation etc.). Sessions were organized 2 days of the week during 6 months for 45–60 minutes in groups of 7–15 participants, supervised by a professional creative therapist.
Measurements
Data were collected at baseline and after 6 months intervention by three trained research assistants who were blinded to group assignment, according to a standardized protocol.
Information on demographic characteristics, perceived health, quality of life, vitality and depression was obtained in a personal interview at the homes of the study participants. Quality of life was measured by the Dementia Quality of Life Instrument (DQoL)[8]. The DQoL consists of 29 items divided in five sub-scales: aesthetics, belonging, negative affect, positive effect and esteem. The respondent was instructed to choose from one of several 5-point response scales placed in front of the respondent on a card. A mean score was calculated for the five subscales as well as for the total DQoL ranging from one to five, with a higher score indicating better quality of life. The Vitality Plus Scale (VPS)[9] was specifically designed to measure the accumulated psychological and physical benefits of exercise participation experienced by older adults. The 10-item scale was designed to capture multiple, interrelated aspects of 'feeling good' relevant to the exercise experience e.g. sleep, energy, bodily pain, appetite, stiffness. The respondent was instructed to choose for each item how they were currently feeling on a 5-point response scale placed in front of the respondent on a card. Depression was assessed with the 30-item version of the Geriatric Depression Scale [10, 11].
Furthermore, two single questions 'How would you rate your health' and 'How would you rate your health compared to people of your age' were added. Respondents could choose one answer from a five-point and a three-point response scale, respectively. For both scales a higher score indicates better health.
Disability was assessed with questions concerning the difficulty with performing 17 Activities of Daily Living (ADL). For each item, the scores were recalculated ranging from 0 (can perform without difficulty or with difficulty but without help) to 1(can perform only with help or unable to perform).
Statistical analysis
Data were analyzed using SPSS for Windows (release 7.5.2) and MlwiN (1998, version 1.02.0002).
Descriptive data are reported for variables of interest (percentage, mean, SD). Analysis of variance and Chi2-tests were used to compare groups at baseline. To evaluate the effects of the interventions multilevel analysis was used. Using this technique, regression coefficients can be adjusted for the clustering of observations within one home that leads to dependency of observations of different subjects within one home. In the multi-level analysis two levels were defined: 1) patient and 2) home. A linear model was used to study the effect of all three interventions on the continuous outcome values. The parameters of interest are the regression coefficients (beta) indicating the effect of the intervention of interest, compared to the control group. In the 'crude' model the outcome value at 6 months was only adjusted for the value at baseline. In the secondary analyses, adjustments were made for gender, age and class attendance. Regression coefficients and 95% confidence intervals for the basic and the adjusted model are reported.
The trial was designed to randomize 60 subjects to each intervention group, taking into account a dropout percentage of 25% with an alpha of 5% and a power of 80%. Primary analyses were conducted by intention-to-treat with participants analyzed according to the initial randomized assignment. Post-hoc secondary analyses were performed including only those subjects who attended at least 75% of all exercise classes.