Sample
Data were drawn from the 2014 German Health Update (hereafter: GEDA 2014). The GEDA 2014 is a population-based cross-sectional health interview survey conducted on behalf of the Robert-Koch-Institute as part of the German Federal Ministry of Health. Ethics approval for the GEDA 2014 was obtained by the Robert-Koch-Institute and all participants provided informed consent to participate. The purpose of the GEDA is to provide a health monitoring survey that produces reliable information on the actual German adult population’s health status, health determinants and health care utilization [20].
A overview of the methods used in the GEDA 2014 is available elsewhere [20]. Conducted between November 2014 and July 2015, a two-stage stratified cluster sampling approach was used to recruit persons aged ≥18 years with permanent residence in Germany. Two modes of data collection were used: [i] self-administered web questionnaire (SAQ-Web); and [ii] self-administered paper questionnaire (SAQ-Paper). Initially, 90,102 invitations to participate were sent, with 24,016 fully completed (response rate= 26.9%), with 11,253 via SAQ-Web (45.3%) and 13,571 via SAQ-Paper (54.7%) [17, 20].
In the current study, we only included data from those who fully responded to the physical activity items. To increase generalisability, we did not apply any further inclusion/exclusion criteria [21-24]. Additionally, since the German physical activity guidelines for MVPA and MSE apply to both adults (aged 18–64 years) and older adults (aged ≥65 years) [9], we included adults aged ≥18 years.
Physical activity (aerobic MVPA and MSE) assessments
Self-reported physical activity levels were assessed using the European Health
Interview Survey Physical Activity Questionnaire (EHIS-PAQ) [25]. The EHIS-PAQ has been shown to be a reliable and valid physical activity assessment tool for use in public health surveillance, and an overview of the development, design and psychometric testing this instrument has been described elsewhere [25]
Aerobic MVPA
Consistent with standardised protocols [25], to count towards meeting the aerobic MVPA guideline, we included physical activity accrued within the domains of: [i] moderate-to-vigorous aerobic recreational physical activity (e.g. Nordic walking, brisk walking, ball games, jogging, bicycling, swimming, aerobics, rowing, badminton); and [ii] transport-related physical activity (e.g. walking/cycling). For these two domains, respondents were asked to consider physical activity during a ‘typical week’, with the bout of activity having to last for ≥10 minutes. In each domain, respondents also were asked to report the number of days per week and total time spent (hours/minutes). MVPA was then summed the reported in the two domains to provide a weekly aerobic MVPA estimate. A validation study showed that when assessing moderate-to-vigorous aerobic recreational and transport-related physical activity, the EHIS-PAQ items have ‘good’ test-retest reliability (Intraclass correlation coefficient [ICC] =0.72-0.73) and acceptable concurrent validity (Spearman’s rank order correlation =0.36-0.43), using accelerometery as the standard [25].
Concordant with the German physical activity guidelines (9), participants were dichotomised as either [i] ‘meeting the aerobic MVPA guidelines’ (≥150 minutes/week of moderate-intensity or ≥75 minutes/week of vigorous-intensity or an equivalent combination of both), or [ii] ‘not meeting the aerobic MVPA guidelines’ (not meeting the above classification).
Muscle-strengthening exercise
To assess participation in MSE, respondents were asked, “In a typical week, on how many days do you carry out physical activities specifically designed to strengthen your muscles such as doing resistance training or strength exercises? Include all such activities even if you have mentioned them before.”. When considering this question, respondents were prompted to consider a range of MSE-related activities, such as resistance training, strength exercises (using weights, elastic band, own body weight, etc.), knee bends (squats) and push-ups (press-ups). This item has shown to have ‘fair’ test-retest reliability (ICC= 0.55) [25], and similar items have shown evidence of concurrent validity, using the two or more MSE days/week threshold against metabolic syndrome [26].
According to the German physical activity guidelines [9], participants were dichotomised as either; [i] ‘meeting the MSE guideline’ (≥2 days/week of MSE involving major muscle groups), or [ii] ‘not meeting the MSE guideline’ (not meeting the above classification).
Meeting the combined MVPA-MSE guidelines
Consistent with the German public health guidelines [9], the sample was dichotomised as either: [i] ‘meeting the combined aerobic MVPA-MSE guidelines’ (≥150 MVPA minutes/week AND ≥2 days/week of MSE); or [ii] ‘not meeting the aerobic MVPA-MSE guidelines’ (not meeting the above classification).
Sociodemographic, socioeconomic status and lifestyle variables
Sociodemographic (sex, age, nationality, socioeconomic status) and lifestyle variables (self-rated health, body mass index [BMI]) were assessed using standard survey items. Each sociodemographic/lifestyle variable was chosen due to its known association with combined MVPA-MSE [21-24], and sub-categories were created to be consistent with previous studies from the GEDA 2014 [27]. Socioeconomic status (low, medium or high) was assessed using the previously validated, German-specific, Socioeconomic SES index (SES Index) [27]. An overview of development of the SES Index can be found elsewhere [27]. The SES Index is based on information from three constructs: [i] formal education/vocational training; [ii] occupational status; and [iii] equivalenced to net household income. This index is calculated as a total points score on the basis of the point values assigned to each construct. A distribution-based distinction of three status groups is made for the analyses, with the low and high status groups each comprising 20% and the medium status group 60% of the population [27]. Self-rated health was assessed on a 5-point scale (1= ‘very good’ to 5= ‘very poor’). BMI was calculated based on self-reported measured height and weight, and categorised into: <18.5 kg/m2 (underweight); from ≥18.5 kg/m2 to <25 kg/m2 (acceptable weight range); from ≥25 kg/m2 to <30 kg/m2 (overweight); and ≥30 kg/m2 (obese).
Statistical analysis
All statistical analyses was conducted using Complex Sample Module, IBM SPSS 24.0 statistical software (SPSS Inc. an IBM Company, Chicago, IL). To enhance population representativeness, each GEDA 2014 responded was provided with a sample weight to correct for non-response. Detailed information on the methodological considerations for the sample weights in the GEDA 2014 is available elsewhere [28, 29].
To assess the primary study aim, weighted percentages and their 95% confidence intervals (95% CI) were calculated for: [i] meeting the aerobic MVPA guideline; [ii] meeting the MSE guideline; [iii] meeting both aerobic MVPA-MSE guidelines. Chi-squared tests were used to test the unadjusted differences between the prevalence rates by sociodemographic and lifestyle variables.
To assess the secondary aim, generalized linear models using Poisson regression with robust error variance were conducted to calculate prevalence ratios (PRs) between sociodemographic and lifestyle variables, and: [i] meeting/not meeting aerobic MVPA guideline; [ii] meeting/not meeting the MSE guideline; [iii] meeting/not meeting the combined MVPA-MSE guidelines. Each model included the following explanatory variables: sex (reference group [ref] = “male”); age (ref = “18-29 years”); socioeconomic status (ref = “high”); nationality (ref= “German”); self-rated health (ref = “very good”); and BMI (ref = “normal weight”). For these Poisson regression analyses, PRs and their 95% CIs were reported.
Table 1: Proportions (weighteda) of the GEDA 2014 sample meeting the aerobic moderate to-vigorous aerobic physical activity (MVPA) guidelineb, muscle strengthening exercise guidelinec and combined aerobic MVPA and muscle strengthening exercise guidelines: overall and by sociodemographic and lifestyle factors.
|
|
|
Met MVPA guidelineb
|
Met muscle-strengthening exercise guidelinec
|
Met both guidelinesd
|
|
ne
|
% (95% CI)
|
% (95% CI)
|
% (95% CI)
|
Total
|
24,016
|
45.3 (44.5-46.0)
|
29.4 (28.7-30.1)
|
22.6 (21.9-23.2)
|
Sex
|
ne (%f)
|
|
|
|
|
Male
|
10,873 (48.9)
|
48.0 (46.8-49.2)
|
31.2 (30.2-32.3)
|
24.7 (23.7-25.7)
|
|
Female
|
13,144 (51.1)
|
42.6 (41.5-43.6)
|
27.6 (26.7-28.6)
|
20.5 (19.6-21.3)
|
p-value*
|
|
<0.001
|
<0.001
|
<0.001
|
Age (years)
|
|
|
|
|
|
18-29
|
3,888 (16.9)
|
51.2 (49.1-53.2)
|
39.4 (37.4-41.4)
|
30.1 (29.2-32.9)
|
|
30-44
|
5,325 (22.2)
|
41.8 (40.1-43.5)
|
24.8 (23.4-26.3)
|
19.4 (18.1-20.8)
|
|
45-64
|
8,977 (36.4)
|
46.7 (45.5-47.9)
|
27.8 (26.7-28.9)
|
21.9 (20.9-23.0)
|
|
≥65
|
5,826 (24.5)
|
41.8 (40.2-43.5)
|
29.0 (27.6-30.4)
|
20.2 (18.9-21.6)
|
p-value*
|
|
<0.001
|
<0.001
|
<0.001
|
Socioeconomic status
|
|
|
|
|
|
Low
|
3,906 (20.3)
|
33.4 (31.5-35.2)
|
22.7 (21.2-24.4)
|
15.1 (13.7-16.5)
|
|
Medium
|
13,437 (59.8)
|
45.2 (44.1-46.2)
|
29.8 (28.9-30.8)
|
22.8 (22.0-23.7)
|
|
High
|
6,620 (19.9)
|
56.8 (55.3-58.2)
|
34.7 (33.4-36.1)
|
37.1 (35.7-38.5)
|
p-value*
|
|
<0.001
|
<0.001
|
<0.001
|
Nationality
|
|
|
|
|
|
German
|
22,085 (96.4)
|
45.4 (44.6-46.2)
|
29.4 (28.7-30.2)
|
22.5 (21.9-23.2)
|
|
Non-German, but EU
|
400 (1.8)
|
47.4 (41.4-53.4)
|
30.9 (25.6-36.7)
|
25.5 (20.6-31.1)
|
|
Non-German, not EU
|
319 (1.8)
|
35.9 (29.6-42.7)
|
26.7 (21.0-33.2)
|
20.9 (15.8-27.2)
|
|
p-value*
|
|
0.06
|
0.157
|
0.04
|
Self-rated healthf
|
|
|
|
|
|
Very good
|
3,729 (14.8)
|
62.0 (59.9-63.9)
|
40.7 (33.8-42.7)
|
35.5 (33.6-37.4)
|
|
Good
|
12,488 (53.4)
|
47.8 (46.7-48.9)
|
29.7 (28.8-30.7)
|
23.2 (22.3-24.1)
|
|
Moderate
|
5,570 (26.3)
|
35.1 (33.6-36.6)
|
23.7 (22.4-26.1)
|
16.1 (14.9-17.3)
|
|
Poor
|
938 (4.8)
|
23.3 (20.2-26.7)
|
23.4 (20.4-26.6)
|
11.8 (9.5-14.6)
|
|
Very poor
|
134 (0.7)
|
13.9 (8.3-22.2)
|
16.6 (10.5-25.2)
|
5.6 (2.6-11.6)
|
p-value*
|
|
<0.001
|
<0.001
|
<0.001
|
Body Mass Index (kg/m2)f
|
|
|
|
|
|
Underweight (<18.5)
|
430 (1.8)
|
38.6 (33.1-44.4)
|
27.8 (23.0-33.2)
|
18.5 (14.4-23.3)
|
|
Normal (≥18.5-<25)
|
10,671 (44.1)
|
51.3 (50.1-52.5)
|
34.3 (33.2-35.4)
|
27.2 (26.2-28.3)
|
|
Overweight (25– <30)
|
7,895 (35.9)
|
45.3 (44.0-46.6)
|
28.5 (27.3-29.7)
|
21.9 (20.8-23.0)
|
|
Obese (≥30)
|
3,824 (18.1)
|
31.7 (29.9-33.5)
|
19.6 (18.2-21.2)
|
13.0 (11.8-14.3)
|
|
p-value*
|
|
<0.001
|
<0.001
|
<0.001
|
a Sample weights provided by the GEDA 2014 (30, 31).
b To meet the MVPA guideline respondents had to report engaging in at least 150 minutes per week of moderate-intensity physical activity or 75 minutes of vigorous-intensity physical activity per week, or an equivalent combination both, and accumulated in bouts of at least 10 consecutive minutes during leisure time and for transport.
c To meet muscle-strengthening exercise guideline the guideline respondents had to report engaging in muscle strengthening activity at least two days per week.
d Meeting both guidelines.
e Raw unweighted number of responses.
f Weighted percentage.
g Numbers different to total sample due to missing responses.
*p-value for X2 test.
|