Hamer et al. conducted a 13-year longitudinal study on the predictive
ability of self-reported physical activity on physical activity measured
by accelerometers (1). Participants were 394 healthy men and women aged 54
years on average. They concluded that the habits of physical activity in
adulthood are partly tracked into older age. About their attractive
report, I have several concerns on their statistical outcomes....
Hamer et al. conducted a 13-year longitudinal study on the predictive
ability of self-reported physical activity on physical activity measured
by accelerometers (1). Participants were 394 healthy men and women aged 54
years on average. They concluded that the habits of physical activity in
adulthood are partly tracked into older age. About their attractive
report, I have several concerns on their statistical outcomes.
First, Hamer et al. categorized self-reported physical activity into
four groups, and analysis of variance on accelerometer-derived physical
activities was made by adjusting several confounders. They adopted general
linear models as multivariate analysis in combination with correlation
coefficient (CC). Although they concluded their outcome from that
statistical significance, the level of association presented by CC was
weak and there was no presentation of explanation rate to predict
accelerometer-derived physical activities from multivariate analysis.
Second, I appreciate their long term follow-up of the target
participants, but their analysis was the trend analysis, presenting that
groups who declared high levels of self-reported physical activity
subsequently showed high objective physical activity on average. On this
point, individual agreement of physical activity over 13 years should be
presented such as intra-class CC, concordance CC and the Bland-Altman
plot, which would improve the quality of study.
Third, I understand that the self-reported physical activity and
objective physical activity by accelerometers have different meaning on
activity monitoring (2). If the authors assume the physical activity by
accelerometers as a gold standard, please present validation data for the
accelerometer around the waist to monitor physical activity. Relating to
the selection of indicators on physical activity, predictive ability of
self-reported physical activity for the same indicator after 13 years is
also a simple and understandable for their study. In this case, (weighted)
kappa statistics would become useful statistical indicator for the
agreement.
Anyway, caution should be paid on the validity of accelerometer as a
monitoring tool for physical activity or sedentary behaviour from mid-life
to early old age (3).
References
1. Hamer M, Kivimaki M, Steptoe A. Longitudinal patterns in physical
activity and sedentary behaviour from mid-life to early old age: a
substudy of the Whitehall II cohort. J Epidemiol Community Health
2012;66:1110-5.
2. Martinez-Gomez D, Gomez-Martinez S, Ruiz JR, et al. Objectively-
measured and self-reported physical activity and fitness in relation to
inflammatory markers in European adolescents: the HELENA Study.
Atherosclerosis 2012;221:260-7.
3. Evenson KR, Buchner DM, Morland KB. Objective measurement of
physical activity and sedentary behavior among US adults aged 60 years or
older. Prev Chronic Dis 2012;9:E26.
"Traffic-related pollution," especially diesel combustion produced,
may be shown to increase testosterone. It is my hypothesis that increased
maternal testosterone increases preeclampsia
(http://anthropogeny.com/Incresing%20Testosterone%20and%20Preeclampsia.htm
).
I suggest the findings of Pereira, et al., may be explained by
increased maternal testosterone.
"Traffic-related pollution," especially diesel combustion produced,
may be shown to increase testosterone. It is my hypothesis that increased
maternal testosterone increases preeclampsia
(http://anthropogeny.com/Incresing%20Testosterone%20and%20Preeclampsia.htm
).
I suggest the findings of Pereira, et al., may be explained by
increased maternal testosterone.
We all know eating together as a family can boost conversation,
foster closeness and encourage healthy ways with food. However, a 2011
survey of 1354 people for the insurance firm Cornish Mutual found 48% of
British households do not share a meal every day. [1]
This study shows that by having a family dinner together it can
increase children's daily fruit and vegetable intake to reach the 5 A Day
target. It rei...
We all know eating together as a family can boost conversation,
foster closeness and encourage healthy ways with food. However, a 2011
survey of 1354 people for the insurance firm Cornish Mutual found 48% of
British households do not share a meal every day. [1]
This study shows that by having a family dinner together it can
increase children's daily fruit and vegetable intake to reach the 5 A Day
target. It reinforces the view that children learn more from what adults
do than what they say, therefore it is the parental role modelling that
helps shape their future habits.
The strengths of this study are its large sample size (2383 children)
and reliable methods of assessing dietary intake through a validated food
intake tool. However, there are limitations which have not been noted by
the researchers.
This is a single sample of London schoolchildren taking part in
trials assessing school gardening and diet. We do not know whether the
children who were taking part in this trial may have particular
characteristics that make them different from, for example, children
selected from a completely random primary school sample. Also, the
children in this London area may not be representative of the entire UK
population in terms of culture and ethnicity, which may be related to
family eating patterns.
While home environment and parental food attitudes are likely to
influence the child's food intake, there may be other factors such as
children's preference, social factors or peer pressure. One or a
combination of these factors could directly influence the child's food
intake.
In the United States, the month of October is the national "Eat
Better, Eat Together Month". [2] A tool kit has been developed to promote
family meal time. [3]
If your family isn't already making dining together a priority, now
is the perfect time to start!
REFERENCES
1. Deborah Clark Associates. Press release: Half of UK families are
not eating together. 24 February 2011. http://www.dca-pr.co.uk/Latest-
News/Cornish-Mutual/Half-of-UK-families-are-not-eating-together-123.aspx
Hamer et al. conducted a 13-year longitudinal study on the predictive ability of self-reported physical activity on physical activity measured by accelerometers (1). Participants were 394 healthy men and women aged 54 years on average. They concluded that the habits of physical activity in adulthood are partly tracked into older age. About their attractive report, I have several concerns on their statistical outcomes....
"Traffic-related pollution," especially diesel combustion produced, may be shown to increase testosterone. It is my hypothesis that increased maternal testosterone increases preeclampsia (http://anthropogeny.com/Incresing%20Testosterone%20and%20Preeclampsia.htm ).
I suggest the findings of Pereira, et al., may be explained by increased maternal testosterone.
Conflict of Interest:
...We all know eating together as a family can boost conversation, foster closeness and encourage healthy ways with food. However, a 2011 survey of 1354 people for the insurance firm Cornish Mutual found 48% of British households do not share a meal every day. [1]
This study shows that by having a family dinner together it can increase children's daily fruit and vegetable intake to reach the 5 A Day target. It rei...
Pages