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Physical activity prevented functional decline among frail community-living elderly subjects in an international observational study
Journal of Clinical Epidemiology 60 (2007) 518e524
Physical activity prevented functional decline among frail community-living elderly subjects in an international observational study Francesco Landia,*, Graziano Ondera, Iain Carpenterb, Matteo Cesaria,c, Manuel Soldatoa, Roberto Bernabeia a
Department of Gerontology-Geriatric, Catholic University Sacred Heart, Rome, Italy b Centre for Health Services Studies, University of Kent, UK c Department of Aging and Geriatric Research, University of Florida e College of Medicine, Gainesville, FL, USA Accepted 12 September 2006
Abstract Objectives: The aims of the study were to describe the prevalence of physical activity in a sample of older adults in home care in Europe and to examine the relationship between physical activity and incident disability. Study Design and Setting: Study population consisted of a random sample of 2,005 subjects aged 65 or older admitted to home care programs in 11 European Home Health Agencies who participated in AgeD in HOme Care project. Participants who reported spending 2 or more hours of physical activities in last 3 days were defined physically active. Disability performing activities of daily living was defined as the need of assistance in one or more of the following ADL: eating, dressing, transferring, mobility in bed, personal hygiene, and toileting. Results: More than 50% of participants were physically active. During a median follow-up of 12 months, 370 subjects (15%) became disabled. After adjusting for age, gender, and other possible confounding variables, active subjects were significantly less likely to become disabled compared to those reporting no or very low-intensity physical activity (OR, 0.67; 95% CI 0.53e0.84). Conclusions: These findings support the possibility that physical activity has an independent effect on functional autonomy among frail and old people. Ó 2007 Elsevier Inc. All rights reserved. Keywords: Physical activity; Disability; Frail elderly; Home care; MDS-HC; AdHOC project
1. Introduction Physical activity is directly correlated to improvements in mortality, morbidity, and disability. Exercise capacity and physical activity are associated with lower all-cause mortality and with lower morbidity and mortality rates from cardiovascular diseases [1e5]. Benefits of physical activity also include reductions in risks of stroke [6], diabetes mellitus [7], cancer [8], and osteoporosis [9]. Physical activity started in late life continues to improve the functional autonomy and to reduce mortality, having a strong effect on longevity, even when controlling for potential adverse risk factors such as smoking, hypertension, family history of hereditary diseases (i.e., cardiovascular
* Corresponding author. Centro Medicina dell’Invecchiamento (CEMI), Istituto di Medicina Interna e Geriatria, Universita’ Cattolica del Sacro Cuore, Largo Agostino Gemelli, 8, 00168 Rome, Italy. Tel.: þ3906-3388546; fax: þ39-06-3051911. E-mail address: [email protected] (F. Landi). 0895-4356/07/$ e see front matter Ó 2007 Elsevier Inc. All rights reserved. doi: 10.1016/j.jclinepi.2006.09.010
diseases, cancer, diabetes), and obesity [10,11]. However, the relative contribution of low and moderate intensity of habitual physical activities to reduce disability is still unclear. Indeed some authors have demonstrated that only participation in vigorous physical activity and/or highintensity exercise program is associated with reductions in functional decline [12e14], whereas others have extended these benefits to low-moderate activities [15e17]. Nonetheless, these studies almost invariably excluded elderly patients, especially the oldest ones, and greatly underrepresented women. Moreover, these studies have screened out patients with preserved functional status, thereby limiting the generalizability of the findings. Thus, despite the epidemiological relevance of disability among older individuals, there is a paucity of data to elucidate the impact of physical activity of the more ‘‘typical’’ frail older subjects. Although it is well established that exercise activity protects against loss of physical function in adults, few studies have explored the effects of home-based leisure physical activity across a broad spectrum of age. In fact,
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most of the physical activity intervention studies focused on younger adult population. Furthermore, the best physical activity program for obtaining appropriate health benefits among older people has not yet been identified. The aims of the study was 1) to describe the prevalence of moderate-intensity physical activity in a large European population of frail and very old people living in community and 2) to examine the relationship between physical activity and incident disability.
2. Methods 2.1. Study population The study population consisted of a random sample of elderly patients admitted to the home care programs in 11 different European Home Health Agenciesdfrom 2001 to 2003dwho participated in the AgeD in HOme Care (AdHOC) project, under the sponsorship of the European Union [18]. The AdHOC Project aimed to identify a model of Home Care for the elderly through the analysis of the structural and organizational characteristics of Home Care Services in 11 European countries, along with the clinical and functional characteristics of their clients. For each site, the sample was obtained by a computer driven randomization of all subjects aged 65 years or more already receiving home care services at the beginning of the study. When specific services (e.g., ‘‘integrated’’ or ‘‘social’’ only) were provided by different agencies, the sample from each agency reflected the overall proportion of patients receiving the services of interest. Specifically, the home care patients were assessed in the following urban areas: Prague (Czech Republic, n 5 428), Copenhagen (Denmark, n 5 466), Helsinki (Finland, n 5 187), Amiens (France, n 5 381), Nurnberg and Bayreuth (Germany, n 5 607), Reykjavik (Iceland, n 5 405), Monza (Italy, n 5 412), Amsterdam (The Netherlands, n 5 198), Oslo (Norway, n 5 388), Stockholm (Sweden, n 5 246), Maidstone and Ashford (United Kingdom, n 5 289). This cross-national population-based, longitudinal, multi-linked database comprises (1) data collected with the interRAI (www.interrai.org) version 2.0 Minimum Data Set for Home Care (MDS-HC); (2) data on all the medications used by each patient at the time of the MDS-HC assessmentddrugs were coded using the Anatomical Therapeutic and Chemical (ATC) codes; (3) data on vital status; and (4) data on settings, service structures, and delivery recorded on a specifically designed form. All patients in the sample were assessed at baseline by a trained staff who collected data on the MDS-HC form following the guidelines published in the MDS-HC manual [19], independent of the study protocol. In Finland, France, Germany, and Iceland, assessments were conducted by agency personnel, whereas in all other countries, they were conducted by research assistants recruited for the project.
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All received a standardized training program on how to complete the assessment instrument [20]. Ethical approval for the study was obtained in all countries according to local regulations. Patients invited to take part in the study were free to decline participation. Patient consent was obtained with assurance of data confidentiality.
2.2. MDS-HC assessment data The MDS-HC [19] contains over 350 data elements including sociodemographic variables, numerous clinical items about both physical and cognitive status, as well as all clinical diagnoses. The MDS-HC also includes information about an extensive array of signs, symptoms, syndromes, and treatments being provided [19]. A variety of different, multi-item summary scales are embedded in the MDS-HC measuring, for example, physical function (activities of daily livingdADLs) [21] and cognitive status (cognitive performance scaledCPS) [21]. In addition, participants were asked to report if they were able to climb stairs without help. MDS items have been found to have excellent interrater and testeretest reliability when completed by nurses performing usual assessment duties (average weighted Kappa 5 0.8) [22,23]. Furthermore, the MDS-HC has already paved the way to a representative database that proved a powerful tool for health researches [24,25].
2.3. Physical activity According to MDS-HC manual [26], we used a single question about the average number of hours spent in the last 3 days in ‘‘domestic’’ activitiesdsuch as light housework, cleaning house, or gardeningdor chosen physical activitiesdsuch as recreation, going out to shop or walk, running, bicycling, or specific exercise programs. This item of MDS-HC form (H6b) is coded as 0 if physical activities are equal or greater than 2 hours and 1 if less than 2 hours in the last 3 days. Assessing these activities is in accordance with the recent American College of Sports Medicine guidelines that stated all recommendation in terms of units of time [27]. Furthermore, for the older people, it is easy to think in terms of time devoted to physical activity rather than in terms of energy expenditure. The assessors were instructed to ask simple and direct questions about whether the patients experienced such physical activities. Because some patients had limitations in verbal communication, the assessors were also instructed to directly observe such persons and eventually to ask family about patient’s lifestyle. It is important to highlight that this specific MDSHC item has already paved the way to investigate the effect of physical activity on different outcomes among frail elderly people [11,28]. The average weighted Kappa interrater reliability level for this item is 0.70, indicating an excellent reliability [19].
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2.4. Disability outcomes Patients were examined at home at baseline and every 6 months for 1 year. At baseline and at the six semiannual follow-up assessments, the presence of disability in various domains of functioning was measured. The outcome of the present study was disability performing ADLs, defined as the need of assistance in one or more of the following ADL: eating, dressing, transferring, mobility in bed, personal hygiene, and toileting. Only subjects who did not report this level of disability at baseline were included in analyses assessing effect of physical activity on onset of disability.
2.5. Analytic approach All demographic variables, measures of physical and cognitive function and comorbid conditions were gathered at initial MDS-HC assessment on admission to the home care program. From the initial sample of 4,007 subjects, we excluded participants with missing data on physical activity (N 5 43) and those with terminal illness (N 5 32). Then, we excluded participants reporting ADL disability at baseline assessment (N 5 1,465). In the resulting sample of 2,467 participants without ADL disability at baseline, 462 were lost to follow-up (including 114 participants admitted to nursing home and 14 who left the study area). Therefore, the study was based on a sample of 2,005 subjects. Participants were divided into two groups based on the amount of physical activity: active (2 or more hours during the last 3 days, n 5 1,089); sedentary (less than 2 hours during the last 3 days, n 5 916). Data were analyzed first to obtain descriptive statistics. Continuous variables are presented as mean values 6 standard deviation. We evaluated trends of sociodemographic variables and indicators of disease severity using the Fisher exact test. Differences between continuous variables were assessed by ANOVA comparisons for normally distributed parameters; otherwise, the KruskaleWallis test was adopted. Binary logistic regressions were performed to evaluate the effect of physical activity on the onset of ADL disability. All subjects who reported ADL disability at baseline were excluded from the analyses. The outcome was considered present if participants reported ADL disability at any follow-up interviews. Variables included in the model were those associated with physical activity at a P-value !0.20. Analyses are adjusted for age, gender, cognitive performance scale score, impaired vision, ischemic heart disease, congestive heart failure, stroke, peripheral vascular disease, chronic obstructive pulmonary disease (COPD), osteoarthritis, depression, number of medications, and country. In an additional analysis to explore the effect of physical activity in participants without functional limitations, we repeated logistic regression models in a subgroup of participants who were able to climb stairs without help at the
baseline assessment. Finally, in consideration of the fact that in a previous publication [18] characteristics of participants were discriminated in different clusters, based on sociodemographic, functional, and clinical variables, analysis was repeated after stratification of the sample across two clusters. Cluster 1 includes Czech Republic, Denmark, Finland, Iceland, The Netherlands, Norway, and Sweden; Cluster 2 includes France, Germany, Italy, and United Kingdom. All analyses were performed using SPSS software.
3. Results Main characteristics of the study population are shown in Table 1. Patients were Caucasian, predominately female (78%) with a mean age of 82.1 6 7.0 years. More than 60% of the individuals were aged 80 years or older. Overall, patients had a moderate impairment in cognitive performance; cognitive function was compromised in a small number of patients (less than 20% showed a CPS score more than 2, indicating moderate to severe cognitive impairment). The mean number of diseases was slightly higher among sedentary subjects compared with physically active subjects Table 1 Characteristics of study population according to physical activity Characteristics
Physical activity No physical activity N 5 1,089 (%) n 5 916 (%)
Age, years !80 >80
405 (37) 684 (63)
315 (34) 601 (66)
Gender** Women Men
826 (76) 263 (24)
733 (80) 183 (20)
Living alone
819 (75)
688 (75)
Cognitive performance scale score* 0e1 925 (85) 2e4 156 (14) 5 or more 7 (1)
717 (78) 193 (21) 6 (1)
Impaired vision*
281 (26)
284 (31)
211 234 389 156 131 190 114
(19) (22) (36) (14) (12) (17) (11)
225 239 320 165 130 171 119
(25) (26) (35) (18) (14) (19) (13)
33 74 305 79
(3) (7) (28) (7)
26 71 282 110
(3) (8) (31) (12)
Diseases Ischemic heart disease* Congestive heart failure Hypertension Peripheral vascular disease** Stroke Diabetes Chronic obstructive pulmonary disease Parkinson’s disease Cancer Osteoarthritis Depression* Number of medications* 0e3 4e6 >7
306 (28) 356 (33) 427 (39)
* P-value ! 0.01, ** P-value ! 0.05.
190 (21) 316 (35) 410 (45)
F. Landi et al. / Journal of Clinical Epidemiology 60 (2007) 518e524
(2.0 6 1.6 versus 1.8 6 1.4, respectively). In particular, coronary artery disease, congestive heart failure, peripheral vascular disease, COPD, and depression were more frequent among subjects with no or very low level of physical activity compared with subjects involved in physical activity for at least 2 hours per week. Physical activity for 2 or more hours during the last 3 days was recorded in 56% of participants aged less than 80 years and 53% in those aged 80 years and older (P 5 0.193). Fig. 1 shows that significant geographical variations were evident in the prevalence of physical activity ranging from 26% of Stockholm (Sweden) to 74% of Rotterdam (The Netherlands) and 76% of Helsinki (Finland). A low rate of physical activity was also found in Amiens (France) and Prague (Czech Republic), with 36% and 42% of physically active participants, respectively. During a median follow-up of 12 months from initial MDS-HC assessment, 370 subjects (15%) experienced an incident disability as expressed by the transition from no disability to at least one disability in the following ADL: eating, dressing, transferring, mobility in bed, personal hygiene, and toileting. As shown in Table 2, after adjusting for potential confounders, which included age, gender, cognitive performance scale score, impaired vision, ischemic heart disease, congestive heart failure, stroke, peripheral vascular disease, COPD, osteoarthritis, depression, number of medications, and country, physically active subjects were less likely to become disabled compared to participants with no or very low level of physical activity (Odd Ratio [OR], 0.67; 95% Confidence Intervals [CI] 0.53e0.84). It is important to highlight that this inverse relationship was also significant in the very old age group (OR, 0.72; 95% CI 0.52e0.94) and in both male and female subjects (data not shown). Furthermore, in consideration of the fact that in a previous publication [18] characteristics of participants were discriminated in two different clusters, based on sociodemographic, functional, and clinical variables, analysis
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was repeated after stratification of the sample across two clusters. As shown in Table 2, physically active subjects were less likely to become disabled compared to nonphysical active participants independently of the country. In an additional analysis to explore the effect of physical activity in participants without any functional limitations, we repeated logistic regression models in a subgroup of participants who were able to climb stairs without help at baseline assessment. Among participants who were able to climb stairs without help (n 5 1,118), physical activity was still significantly associated with the outcome (OR 5 0.69; 95% CI 0.48e0.98).
4. Discussion The AdHOC study examines the recipients of community care services in 11 European countries, using information collected with the MDS-HC, a comprehensive and standardized geriatric assessment instrument. The AdHOC database is the first available resource to conduct outcomebased research in recipients of standard community care services and to identify the characteristics of recipients that can result in substantial health benefits. Using this innovative database, the present study shows that a moderate physical activity has an important prognostic influence for geriatric patients living in the community, independently from age and other clinical and functional variables. Even adjusting for several confounders, such as comorbidity and cognitive impairment, incident disability was more frequently reported in the lowest level of physical activity group (less than 2 hours). Our data are consistent with previous studies showing that people who are more physically active present a reduced disability risk compared to those who are less active [15e17]. Analysis of more than 10,000 older adults participating in the Established Populations for Epidemiologic Studies of the Elderly showed an
Prevalence of physical activity (%)
100
80
60
40
20
0
CZ
DK
D
FIN
F
IS
I
NL
NO
S
UK
Total
Fig. 1. Prevalence of physical activity for two or more hours during the last 3 days by country. CZ: Czech Republic (Prague); DK: Denmark (Copenhagen); FIN: Finland (Helsinki); F: France (Amiens); D: Germany (Nurnberg and Bayreuth); IS: Iceland (Reykjavik); I: Italy (Milan); NL: The Netherlands (Amsterdam); N: Norway (Oslo); S: Sweden (Stockholm); UK: United Kingdom (Maidstone and Ashford).
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Table 2 Risk of disability according to physical activity Incident disability N (%)
Crude model OR (95% CI)
Adjusted modela OR (95% CI)
Total sample No physical activity (n 5 916) Physical activity (n 5 1,089)
205 (22,4%) 165 (15,2%)
1 (Reference) 0.62 (0.48e0.78)
1 (Reference) 0.67 (0.53e0.84)
Age !80 No physical activity (n 5 315) Physical activity (n 5 405)
69 (21,9%) 57 (14,1%)
1 (Reference) 0.58 (0.40e0.86)
1 (Reference) 0.62 (0.41e0.93)
Age O80 No physical activity (n 5 601) Physical activity (n 5 684)
136 (22,6%) 108 (15,8%)
1 (Reference) 0.64 (0.48e0.85)
1 (Reference) 0.70 (0.52e0.94)
Cluster 1 No physical activity (n 5 717) Physical activity (n 5 880)
138 (19,2%) 120 (13,6%)
1 (Reference) 0.66 (0.51e0.87)
1 (Reference) 0.71 (0.53e0.94)
Cluster 2 No physical activity (n 5 199) Physical activity (n 5 208)
67 (33,7%) 45 (21,6%)
1 (Reference) 0.54 (0.35e0.85)
1 (Reference) 0.60 (0.37e0.96)
Cluster 1 includes Czech Republic, Denmark, Finland, Iceland, The Netherlands, Norway, and Sweden. Cluster 2 includes France, Germany, Italy, and United Kingdom. a Adjusted for age, gender, cognitive performance scale score, impaired vision, ischemic heart disease, congestive heart failure, stroke, peripheral vascular disease, COPD, osteoarthritis, depression, number of medications, and country.
almost two-fold increased likelihood of dying without disability among those most physically active compared to those who were sedentary [29]. Similarly, other studies demonstrated that moderate to vigorous leisure-time physical activity decreased the risk of poor physical functioning and had the capacity to postpone the onset of disability [15e17,30,31]. However, to our knowledge the present study is the first to extend these findings to frail and very old subjects. Our results suggest that the inverse association between physical activities and disability is present among frail and very old people aged more than 80 years, too. In this respect, it should be observed that participants in previous studies were younger than participants in our study. The benefits of aerobic exercise, strength training, and/ or vigorous physical activity have already been described and well established [7,32e38]. However, the possibility that exercise could be an effective means of preventing incident disability is not completely clear. In some studies although many intensive exercise programs have shown improvements in physical function, relatively few have shown improvements in disability [33,36]. Furthermore, vigorous training typically is not a reasonable goal for the frail older people, particularly for those who have a high rate of comorbidity. The required intensity of physical activity to achieve various health benefits is still discussed; however, current opinion emphasizes the public health importance of moderate-intensity physical activity [30,39]. Moderate physical activitydsuch as leisure-time activities (i.e., walking, gardening, house-keeping)dis highly attractive for older persons, even those with functional limitations and/or health problems. In addition, these activities are easily undertaken by the oldest age group and do not present substantial
contraindications [40,41]. Over the past decade, recognition of these benefits had led to several consensus statements emphasizing the importance of physical activity in late life. Recent guidelines regarding physical activity from the Centers for Disease Control and Prevention and the American College of Sports Medicine recommend that every adult should accumulate at least 30 minutes of moderate-intensity physical activity on most days of the week [27]. Some limitations of the present study need to be addressed. First, it is important to recognize that many studies have demonstrated sedentary lifestyle making a major contribution to chronic diseases such as coronary artery diseases, cerebrovascular accidents, obesity, diabetes mellitus, and arthritis [36]. On the other hand, severe and chronic diseases may be associated with low physical activity levels. In this respect, we cannot entirely exclude that this reverse causation may have an important part in the association between low physical activity level and elevated disability risk observed in our sample. Reverse causation is particularly likely with diseases with a long natural history preceding disability, such as osteoporosis, arthritis, COPD, and dementia. However, because of the use of MDS-HC, a multidimensional assessment instrument, the present study could comprehensively explore the different domains of elderly status influencing physical activity style and disability occurrence. For this reason and to allow an analysis taking care of the largest number of potential confounders, we included in our model a whole series of variables, as well as comorbidity and measures of cognitive status. The second limitation of the present study is determined by the lack of any documentation concerning how long was the period in which subject was involved in physical activities. For this reason, we cannot exclude that selective
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survivorship of healthier subjects explains all or part of the results observed. In the absence of randomization, it is likely that there are significant differences, which were not considered differences, between the evaluation groups that may have biased the study results and conclusions. For example, it can be hypothesized that physically active subjects received a higher level of medical care. Third, we did not distinguish between different types of physical activity and between different cut-off points for the intensity and frequency of physical activity. Furthermore, no information about the physical activity during the weekend and different activities during winter and summertime were available. While these issues deserve further studies, we were interested in describing the effect of 2 or more hours of daily activities on incident disability. Finally, a more critical consideration is that our sample was composed only of patients considered eligible for home care programs, indicating that a health problem was in place. In this respect, we are not authorized to extend the results to all the community dwelling older individuals. Even though there were some limitations, our results obtained from an international sample of frail elderly subjects expand the knowledge that moderate physical activity carried out as part of everyday activities can be of substantial benefit, maintaining mobility and prolonging independence. Unfortunately, despite the benefits of physical activity, practical advice is often lacking. It is noteworthy that in our sample of older people only 50% do regular moderateintensity physical activity in their leisure time with significant differences across countries. It is difficult to give an explanation for these differences; however, we can hypothesize that cultural factors and sociodemographic inequalities may explain at least in part these results. In this respect, health educational authorities and health care organizations together with primary care physicians should encourage all the older people to be more physically active [42]. In conclusion, our results suggest that even very old, frail, and clinically complex patients may benefit from physical activity. Most notably, physical activity is associated with a reduction in ADL decline that may translate into improved quality of life and, eventually, reduced health care costs. These findings need to be confirmed in prospective, randomized controlled clinical trials, but such trials are exceedingly difficult and expensive in very elderly, frail patients. Until then, physical activity should be considered in all frail elderly patients who have no contraindications.
Acknowledgments This study has been funded by a grant from the Fifth Framework Programme on ‘‘Quality of Life and Management of Living Resources’’ of the European Union. This large and complex study required very substantial commitment from very many staff within the participating
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research organizations and health and social care services of each country. It would not have been possible without their collaboration in the face of many frustrations and time-consuming tasks. Their contribution is gratefully acknowledged by the lead investigator of the study (C. Gobbi). The Partners in each country are Fellows of interRAI, an international research collaboration whose general membership contributed critical advice and support through all stages of the project.
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[29] Leveille SG, Guralnik JM, Ferrucci L, Langlois JA. Aging successfully until death in old age: opportunities for increasing active life expectancy. Am J Epidemiol 1999;149:654e64. [30] Leino-Arjas P, Solovieva S, Riihimaki H, Kirjonen J, Telama R. Leisure time physical activity and strenuousness of work as predictors of physical functioning: a 28 year follow up of a cohort of industrial employees. Occup Environ Med 2004;61:1032e8. [31] Hubert HB, Bloch DA, Oehlert JW, Fries JF. Lifestyle habits and compression of morbidity. J Gerontol A Biol Sci Med Sci 2002;57: M347e51. [32] Fiatarone MA. Fitness and function at the end of life. J Am Geriatr Soc 1995;43:1439e40. [33] Keysor JJ, Jette AM. Have we oversold the benefit of late-life exercise? J Gerontol A Biol Sci Med Sci 2001;56:M412e23. [34] Morris CK, Froelicher VF. Cardiovascular benefits of improved exercise capacity. Sports Med 1993;16:225e36. [35] Fiatarone MA, Marks EC, Ryan ND, Meredith CN, Lipsitz LA, Evans WJ. High-intensity strength training in nonagenarians. Effects on skeletal muscle. JAMA 1990;263:3029e34. [36] Bean JF, Vora A, Frontera WR. Benefits of exercise for community-dwelling older adults. Arch Phys Med Rehabil 2004;85:S31e42. [37] Gill TM, Williams CS, Mendes de Leon CF, Tinetti ME. The role of change in physical performance in determining risk for dependence in activities of daily living among nondisabled community-living elderly persons. J Clin Epidemiol 1997;50:765e72. [38] Carrie`re I, Colvez A, Favier F, Jeandel C, Blain H. Hierarchical components of physical frailty predicted incidence of dependency in a cohort of elderly women. J Clin Epidemiol 2005;58:1180e7. [39] Thompson PD, Buchner D, Pina IL, Balady GJ, Williams MA, Marcus BH, et al. Exercise and physical activity in the prevention and treatment of atherosclerotic cardiovascular disease: a statement from the council on clinical cardiology (subcommittee on exercise, rehabilitation, and prevention) and the council on nutrition, physical activity, and metabolism (subcommittee on physical activity). Circulation 2003;107:3109e16. [40] Morey MC, Pieper CF, Crowley GM, Sullivan RJ, Puglisi CM. Exercise adherence and 10-year mortality in chronically ill older adults. J Am Geriatr Soc 2002;50:1929e33. [41] Fiatarone MA. Exercise in the oldest old: new insights and unanswered questions. J Am Geriatr Soc 2002;50:2089e91. [42] Dubbert PM, Cooper KM, Kirchner KA, Meydrech EF, Bilbrew D. Effects of nurse counseling on walking for exercise in elderly primary care patients. J Gerontol A Biol Sci Med Sci 2002;57:M733e40.
Physical activity prevented functional decline among frail community-living elderly subjects in an international observational study Francesco Landia,*, Graziano Ondera, Iain Carpenterb, Matteo Cesaria,c, Manuel Soldatoa, Roberto Bernabeia a
Department of Gerontology-Geriatric, Catholic University Sacred Heart, Rome, Italy b Centre for Health Services Studies, University of Kent, UK c Department of Aging and Geriatric Research, University of Florida e College of Medicine, Gainesville, FL, USA Accepted 12 September 2006
Abstract Objectives: The aims of the study were to describe the prevalence of physical activity in a sample of older adults in home care in Europe and to examine the relationship between physical activity and incident disability. Study Design and Setting: Study population consisted of a random sample of 2,005 subjects aged 65 or older admitted to home care programs in 11 European Home Health Agencies who participated in AgeD in HOme Care project. Participants who reported spending 2 or more hours of physical activities in last 3 days were defined physically active. Disability performing activities of daily living was defined as the need of assistance in one or more of the following ADL: eating, dressing, transferring, mobility in bed, personal hygiene, and toileting. Results: More than 50% of participants were physically active. During a median follow-up of 12 months, 370 subjects (15%) became disabled. After adjusting for age, gender, and other possible confounding variables, active subjects were significantly less likely to become disabled compared to those reporting no or very low-intensity physical activity (OR, 0.67; 95% CI 0.53e0.84). Conclusions: These findings support the possibility that physical activity has an independent effect on functional autonomy among frail and old people. Ó 2007 Elsevier Inc. All rights reserved. Keywords: Physical activity; Disability; Frail elderly; Home care; MDS-HC; AdHOC project
1. Introduction Physical activity is directly correlated to improvements in mortality, morbidity, and disability. Exercise capacity and physical activity are associated with lower all-cause mortality and with lower morbidity and mortality rates from cardiovascular diseases [1e5]. Benefits of physical activity also include reductions in risks of stroke [6], diabetes mellitus [7], cancer [8], and osteoporosis [9]. Physical activity started in late life continues to improve the functional autonomy and to reduce mortality, having a strong effect on longevity, even when controlling for potential adverse risk factors such as smoking, hypertension, family history of hereditary diseases (i.e., cardiovascular
* Corresponding author. Centro Medicina dell’Invecchiamento (CEMI), Istituto di Medicina Interna e Geriatria, Universita’ Cattolica del Sacro Cuore, Largo Agostino Gemelli, 8, 00168 Rome, Italy. Tel.: þ3906-3388546; fax: þ39-06-3051911. E-mail address: [email protected] (F. Landi). 0895-4356/07/$ e see front matter Ó 2007 Elsevier Inc. All rights reserved. doi: 10.1016/j.jclinepi.2006.09.010
diseases, cancer, diabetes), and obesity [10,11]. However, the relative contribution of low and moderate intensity of habitual physical activities to reduce disability is still unclear. Indeed some authors have demonstrated that only participation in vigorous physical activity and/or highintensity exercise program is associated with reductions in functional decline [12e14], whereas others have extended these benefits to low-moderate activities [15e17]. Nonetheless, these studies almost invariably excluded elderly patients, especially the oldest ones, and greatly underrepresented women. Moreover, these studies have screened out patients with preserved functional status, thereby limiting the generalizability of the findings. Thus, despite the epidemiological relevance of disability among older individuals, there is a paucity of data to elucidate the impact of physical activity of the more ‘‘typical’’ frail older subjects. Although it is well established that exercise activity protects against loss of physical function in adults, few studies have explored the effects of home-based leisure physical activity across a broad spectrum of age. In fact,
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most of the physical activity intervention studies focused on younger adult population. Furthermore, the best physical activity program for obtaining appropriate health benefits among older people has not yet been identified. The aims of the study was 1) to describe the prevalence of moderate-intensity physical activity in a large European population of frail and very old people living in community and 2) to examine the relationship between physical activity and incident disability.
2. Methods 2.1. Study population The study population consisted of a random sample of elderly patients admitted to the home care programs in 11 different European Home Health Agenciesdfrom 2001 to 2003dwho participated in the AgeD in HOme Care (AdHOC) project, under the sponsorship of the European Union [18]. The AdHOC Project aimed to identify a model of Home Care for the elderly through the analysis of the structural and organizational characteristics of Home Care Services in 11 European countries, along with the clinical and functional characteristics of their clients. For each site, the sample was obtained by a computer driven randomization of all subjects aged 65 years or more already receiving home care services at the beginning of the study. When specific services (e.g., ‘‘integrated’’ or ‘‘social’’ only) were provided by different agencies, the sample from each agency reflected the overall proportion of patients receiving the services of interest. Specifically, the home care patients were assessed in the following urban areas: Prague (Czech Republic, n 5 428), Copenhagen (Denmark, n 5 466), Helsinki (Finland, n 5 187), Amiens (France, n 5 381), Nurnberg and Bayreuth (Germany, n 5 607), Reykjavik (Iceland, n 5 405), Monza (Italy, n 5 412), Amsterdam (The Netherlands, n 5 198), Oslo (Norway, n 5 388), Stockholm (Sweden, n 5 246), Maidstone and Ashford (United Kingdom, n 5 289). This cross-national population-based, longitudinal, multi-linked database comprises (1) data collected with the interRAI (www.interrai.org) version 2.0 Minimum Data Set for Home Care (MDS-HC); (2) data on all the medications used by each patient at the time of the MDS-HC assessmentddrugs were coded using the Anatomical Therapeutic and Chemical (ATC) codes; (3) data on vital status; and (4) data on settings, service structures, and delivery recorded on a specifically designed form. All patients in the sample were assessed at baseline by a trained staff who collected data on the MDS-HC form following the guidelines published in the MDS-HC manual [19], independent of the study protocol. In Finland, France, Germany, and Iceland, assessments were conducted by agency personnel, whereas in all other countries, they were conducted by research assistants recruited for the project.
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All received a standardized training program on how to complete the assessment instrument [20]. Ethical approval for the study was obtained in all countries according to local regulations. Patients invited to take part in the study were free to decline participation. Patient consent was obtained with assurance of data confidentiality.
2.2. MDS-HC assessment data The MDS-HC [19] contains over 350 data elements including sociodemographic variables, numerous clinical items about both physical and cognitive status, as well as all clinical diagnoses. The MDS-HC also includes information about an extensive array of signs, symptoms, syndromes, and treatments being provided [19]. A variety of different, multi-item summary scales are embedded in the MDS-HC measuring, for example, physical function (activities of daily livingdADLs) [21] and cognitive status (cognitive performance scaledCPS) [21]. In addition, participants were asked to report if they were able to climb stairs without help. MDS items have been found to have excellent interrater and testeretest reliability when completed by nurses performing usual assessment duties (average weighted Kappa 5 0.8) [22,23]. Furthermore, the MDS-HC has already paved the way to a representative database that proved a powerful tool for health researches [24,25].
2.3. Physical activity According to MDS-HC manual [26], we used a single question about the average number of hours spent in the last 3 days in ‘‘domestic’’ activitiesdsuch as light housework, cleaning house, or gardeningdor chosen physical activitiesdsuch as recreation, going out to shop or walk, running, bicycling, or specific exercise programs. This item of MDS-HC form (H6b) is coded as 0 if physical activities are equal or greater than 2 hours and 1 if less than 2 hours in the last 3 days. Assessing these activities is in accordance with the recent American College of Sports Medicine guidelines that stated all recommendation in terms of units of time [27]. Furthermore, for the older people, it is easy to think in terms of time devoted to physical activity rather than in terms of energy expenditure. The assessors were instructed to ask simple and direct questions about whether the patients experienced such physical activities. Because some patients had limitations in verbal communication, the assessors were also instructed to directly observe such persons and eventually to ask family about patient’s lifestyle. It is important to highlight that this specific MDSHC item has already paved the way to investigate the effect of physical activity on different outcomes among frail elderly people [11,28]. The average weighted Kappa interrater reliability level for this item is 0.70, indicating an excellent reliability [19].
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2.4. Disability outcomes Patients were examined at home at baseline and every 6 months for 1 year. At baseline and at the six semiannual follow-up assessments, the presence of disability in various domains of functioning was measured. The outcome of the present study was disability performing ADLs, defined as the need of assistance in one or more of the following ADL: eating, dressing, transferring, mobility in bed, personal hygiene, and toileting. Only subjects who did not report this level of disability at baseline were included in analyses assessing effect of physical activity on onset of disability.
2.5. Analytic approach All demographic variables, measures of physical and cognitive function and comorbid conditions were gathered at initial MDS-HC assessment on admission to the home care program. From the initial sample of 4,007 subjects, we excluded participants with missing data on physical activity (N 5 43) and those with terminal illness (N 5 32). Then, we excluded participants reporting ADL disability at baseline assessment (N 5 1,465). In the resulting sample of 2,467 participants without ADL disability at baseline, 462 were lost to follow-up (including 114 participants admitted to nursing home and 14 who left the study area). Therefore, the study was based on a sample of 2,005 subjects. Participants were divided into two groups based on the amount of physical activity: active (2 or more hours during the last 3 days, n 5 1,089); sedentary (less than 2 hours during the last 3 days, n 5 916). Data were analyzed first to obtain descriptive statistics. Continuous variables are presented as mean values 6 standard deviation. We evaluated trends of sociodemographic variables and indicators of disease severity using the Fisher exact test. Differences between continuous variables were assessed by ANOVA comparisons for normally distributed parameters; otherwise, the KruskaleWallis test was adopted. Binary logistic regressions were performed to evaluate the effect of physical activity on the onset of ADL disability. All subjects who reported ADL disability at baseline were excluded from the analyses. The outcome was considered present if participants reported ADL disability at any follow-up interviews. Variables included in the model were those associated with physical activity at a P-value !0.20. Analyses are adjusted for age, gender, cognitive performance scale score, impaired vision, ischemic heart disease, congestive heart failure, stroke, peripheral vascular disease, chronic obstructive pulmonary disease (COPD), osteoarthritis, depression, number of medications, and country. In an additional analysis to explore the effect of physical activity in participants without functional limitations, we repeated logistic regression models in a subgroup of participants who were able to climb stairs without help at the
baseline assessment. Finally, in consideration of the fact that in a previous publication [18] characteristics of participants were discriminated in different clusters, based on sociodemographic, functional, and clinical variables, analysis was repeated after stratification of the sample across two clusters. Cluster 1 includes Czech Republic, Denmark, Finland, Iceland, The Netherlands, Norway, and Sweden; Cluster 2 includes France, Germany, Italy, and United Kingdom. All analyses were performed using SPSS software.
3. Results Main characteristics of the study population are shown in Table 1. Patients were Caucasian, predominately female (78%) with a mean age of 82.1 6 7.0 years. More than 60% of the individuals were aged 80 years or older. Overall, patients had a moderate impairment in cognitive performance; cognitive function was compromised in a small number of patients (less than 20% showed a CPS score more than 2, indicating moderate to severe cognitive impairment). The mean number of diseases was slightly higher among sedentary subjects compared with physically active subjects Table 1 Characteristics of study population according to physical activity Characteristics
Physical activity No physical activity N 5 1,089 (%) n 5 916 (%)
Age, years !80 >80
405 (37) 684 (63)
315 (34) 601 (66)
Gender** Women Men
826 (76) 263 (24)
733 (80) 183 (20)
Living alone
819 (75)
688 (75)
Cognitive performance scale score* 0e1 925 (85) 2e4 156 (14) 5 or more 7 (1)
717 (78) 193 (21) 6 (1)
Impaired vision*
281 (26)
284 (31)
211 234 389 156 131 190 114
(19) (22) (36) (14) (12) (17) (11)
225 239 320 165 130 171 119
(25) (26) (35) (18) (14) (19) (13)
33 74 305 79
(3) (7) (28) (7)
26 71 282 110
(3) (8) (31) (12)
Diseases Ischemic heart disease* Congestive heart failure Hypertension Peripheral vascular disease** Stroke Diabetes Chronic obstructive pulmonary disease Parkinson’s disease Cancer Osteoarthritis Depression* Number of medications* 0e3 4e6 >7
306 (28) 356 (33) 427 (39)
* P-value ! 0.01, ** P-value ! 0.05.
190 (21) 316 (35) 410 (45)
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(2.0 6 1.6 versus 1.8 6 1.4, respectively). In particular, coronary artery disease, congestive heart failure, peripheral vascular disease, COPD, and depression were more frequent among subjects with no or very low level of physical activity compared with subjects involved in physical activity for at least 2 hours per week. Physical activity for 2 or more hours during the last 3 days was recorded in 56% of participants aged less than 80 years and 53% in those aged 80 years and older (P 5 0.193). Fig. 1 shows that significant geographical variations were evident in the prevalence of physical activity ranging from 26% of Stockholm (Sweden) to 74% of Rotterdam (The Netherlands) and 76% of Helsinki (Finland). A low rate of physical activity was also found in Amiens (France) and Prague (Czech Republic), with 36% and 42% of physically active participants, respectively. During a median follow-up of 12 months from initial MDS-HC assessment, 370 subjects (15%) experienced an incident disability as expressed by the transition from no disability to at least one disability in the following ADL: eating, dressing, transferring, mobility in bed, personal hygiene, and toileting. As shown in Table 2, after adjusting for potential confounders, which included age, gender, cognitive performance scale score, impaired vision, ischemic heart disease, congestive heart failure, stroke, peripheral vascular disease, COPD, osteoarthritis, depression, number of medications, and country, physically active subjects were less likely to become disabled compared to participants with no or very low level of physical activity (Odd Ratio [OR], 0.67; 95% Confidence Intervals [CI] 0.53e0.84). It is important to highlight that this inverse relationship was also significant in the very old age group (OR, 0.72; 95% CI 0.52e0.94) and in both male and female subjects (data not shown). Furthermore, in consideration of the fact that in a previous publication [18] characteristics of participants were discriminated in two different clusters, based on sociodemographic, functional, and clinical variables, analysis
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was repeated after stratification of the sample across two clusters. As shown in Table 2, physically active subjects were less likely to become disabled compared to nonphysical active participants independently of the country. In an additional analysis to explore the effect of physical activity in participants without any functional limitations, we repeated logistic regression models in a subgroup of participants who were able to climb stairs without help at baseline assessment. Among participants who were able to climb stairs without help (n 5 1,118), physical activity was still significantly associated with the outcome (OR 5 0.69; 95% CI 0.48e0.98).
4. Discussion The AdHOC study examines the recipients of community care services in 11 European countries, using information collected with the MDS-HC, a comprehensive and standardized geriatric assessment instrument. The AdHOC database is the first available resource to conduct outcomebased research in recipients of standard community care services and to identify the characteristics of recipients that can result in substantial health benefits. Using this innovative database, the present study shows that a moderate physical activity has an important prognostic influence for geriatric patients living in the community, independently from age and other clinical and functional variables. Even adjusting for several confounders, such as comorbidity and cognitive impairment, incident disability was more frequently reported in the lowest level of physical activity group (less than 2 hours). Our data are consistent with previous studies showing that people who are more physically active present a reduced disability risk compared to those who are less active [15e17]. Analysis of more than 10,000 older adults participating in the Established Populations for Epidemiologic Studies of the Elderly showed an
Prevalence of physical activity (%)
100
80
60
40
20
0
CZ
DK
D
FIN
F
IS
I
NL
NO
S
UK
Total
Fig. 1. Prevalence of physical activity for two or more hours during the last 3 days by country. CZ: Czech Republic (Prague); DK: Denmark (Copenhagen); FIN: Finland (Helsinki); F: France (Amiens); D: Germany (Nurnberg and Bayreuth); IS: Iceland (Reykjavik); I: Italy (Milan); NL: The Netherlands (Amsterdam); N: Norway (Oslo); S: Sweden (Stockholm); UK: United Kingdom (Maidstone and Ashford).
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Table 2 Risk of disability according to physical activity Incident disability N (%)
Crude model OR (95% CI)
Adjusted modela OR (95% CI)
Total sample No physical activity (n 5 916) Physical activity (n 5 1,089)
205 (22,4%) 165 (15,2%)
1 (Reference) 0.62 (0.48e0.78)
1 (Reference) 0.67 (0.53e0.84)
Age !80 No physical activity (n 5 315) Physical activity (n 5 405)
69 (21,9%) 57 (14,1%)
1 (Reference) 0.58 (0.40e0.86)
1 (Reference) 0.62 (0.41e0.93)
Age O80 No physical activity (n 5 601) Physical activity (n 5 684)
136 (22,6%) 108 (15,8%)
1 (Reference) 0.64 (0.48e0.85)
1 (Reference) 0.70 (0.52e0.94)
Cluster 1 No physical activity (n 5 717) Physical activity (n 5 880)
138 (19,2%) 120 (13,6%)
1 (Reference) 0.66 (0.51e0.87)
1 (Reference) 0.71 (0.53e0.94)
Cluster 2 No physical activity (n 5 199) Physical activity (n 5 208)
67 (33,7%) 45 (21,6%)
1 (Reference) 0.54 (0.35e0.85)
1 (Reference) 0.60 (0.37e0.96)
Cluster 1 includes Czech Republic, Denmark, Finland, Iceland, The Netherlands, Norway, and Sweden. Cluster 2 includes France, Germany, Italy, and United Kingdom. a Adjusted for age, gender, cognitive performance scale score, impaired vision, ischemic heart disease, congestive heart failure, stroke, peripheral vascular disease, COPD, osteoarthritis, depression, number of medications, and country.
almost two-fold increased likelihood of dying without disability among those most physically active compared to those who were sedentary [29]. Similarly, other studies demonstrated that moderate to vigorous leisure-time physical activity decreased the risk of poor physical functioning and had the capacity to postpone the onset of disability [15e17,30,31]. However, to our knowledge the present study is the first to extend these findings to frail and very old subjects. Our results suggest that the inverse association between physical activities and disability is present among frail and very old people aged more than 80 years, too. In this respect, it should be observed that participants in previous studies were younger than participants in our study. The benefits of aerobic exercise, strength training, and/ or vigorous physical activity have already been described and well established [7,32e38]. However, the possibility that exercise could be an effective means of preventing incident disability is not completely clear. In some studies although many intensive exercise programs have shown improvements in physical function, relatively few have shown improvements in disability [33,36]. Furthermore, vigorous training typically is not a reasonable goal for the frail older people, particularly for those who have a high rate of comorbidity. The required intensity of physical activity to achieve various health benefits is still discussed; however, current opinion emphasizes the public health importance of moderate-intensity physical activity [30,39]. Moderate physical activitydsuch as leisure-time activities (i.e., walking, gardening, house-keeping)dis highly attractive for older persons, even those with functional limitations and/or health problems. In addition, these activities are easily undertaken by the oldest age group and do not present substantial
contraindications [40,41]. Over the past decade, recognition of these benefits had led to several consensus statements emphasizing the importance of physical activity in late life. Recent guidelines regarding physical activity from the Centers for Disease Control and Prevention and the American College of Sports Medicine recommend that every adult should accumulate at least 30 minutes of moderate-intensity physical activity on most days of the week [27]. Some limitations of the present study need to be addressed. First, it is important to recognize that many studies have demonstrated sedentary lifestyle making a major contribution to chronic diseases such as coronary artery diseases, cerebrovascular accidents, obesity, diabetes mellitus, and arthritis [36]. On the other hand, severe and chronic diseases may be associated with low physical activity levels. In this respect, we cannot entirely exclude that this reverse causation may have an important part in the association between low physical activity level and elevated disability risk observed in our sample. Reverse causation is particularly likely with diseases with a long natural history preceding disability, such as osteoporosis, arthritis, COPD, and dementia. However, because of the use of MDS-HC, a multidimensional assessment instrument, the present study could comprehensively explore the different domains of elderly status influencing physical activity style and disability occurrence. For this reason and to allow an analysis taking care of the largest number of potential confounders, we included in our model a whole series of variables, as well as comorbidity and measures of cognitive status. The second limitation of the present study is determined by the lack of any documentation concerning how long was the period in which subject was involved in physical activities. For this reason, we cannot exclude that selective
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survivorship of healthier subjects explains all or part of the results observed. In the absence of randomization, it is likely that there are significant differences, which were not considered differences, between the evaluation groups that may have biased the study results and conclusions. For example, it can be hypothesized that physically active subjects received a higher level of medical care. Third, we did not distinguish between different types of physical activity and between different cut-off points for the intensity and frequency of physical activity. Furthermore, no information about the physical activity during the weekend and different activities during winter and summertime were available. While these issues deserve further studies, we were interested in describing the effect of 2 or more hours of daily activities on incident disability. Finally, a more critical consideration is that our sample was composed only of patients considered eligible for home care programs, indicating that a health problem was in place. In this respect, we are not authorized to extend the results to all the community dwelling older individuals. Even though there were some limitations, our results obtained from an international sample of frail elderly subjects expand the knowledge that moderate physical activity carried out as part of everyday activities can be of substantial benefit, maintaining mobility and prolonging independence. Unfortunately, despite the benefits of physical activity, practical advice is often lacking. It is noteworthy that in our sample of older people only 50% do regular moderateintensity physical activity in their leisure time with significant differences across countries. It is difficult to give an explanation for these differences; however, we can hypothesize that cultural factors and sociodemographic inequalities may explain at least in part these results. In this respect, health educational authorities and health care organizations together with primary care physicians should encourage all the older people to be more physically active [42]. In conclusion, our results suggest that even very old, frail, and clinically complex patients may benefit from physical activity. Most notably, physical activity is associated with a reduction in ADL decline that may translate into improved quality of life and, eventually, reduced health care costs. These findings need to be confirmed in prospective, randomized controlled clinical trials, but such trials are exceedingly difficult and expensive in very elderly, frail patients. Until then, physical activity should be considered in all frail elderly patients who have no contraindications.
Acknowledgments This study has been funded by a grant from the Fifth Framework Programme on ‘‘Quality of Life and Management of Living Resources’’ of the European Union. This large and complex study required very substantial commitment from very many staff within the participating
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research organizations and health and social care services of each country. It would not have been possible without their collaboration in the face of many frustrations and time-consuming tasks. Their contribution is gratefully acknowledged by the lead investigator of the study (C. Gobbi). The Partners in each country are Fellows of interRAI, an international research collaboration whose general membership contributed critical advice and support through all stages of the project.
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