Page 67 - Sember, Vedrana, and Shawnda A. Morrison. 2018. The Mind-Body Connection. Koper: University of Primorska Press.
P. 67
Physical Activity in Numbers
Case-Crossover Study Design. Case-crossover studies are retrospect-
ive and the case serves as his/her own control for some compar-
ison issues (Woodward, 2013). These studies are good where the
outcome is acute and well defined (Rothman et al., 2008). The dis-
advantage of case-crossover studies is risk for having recall bias.
Case-crossover studies require careful selection of period and care-
ful selection of timing and the length of the windows. Experience
has shown that case-crossover design applies best if the exposure
is intermittent (Maclure & Mittleman, 2000). Broderick et al. (2012)
searched associations between physical activity and risk of bleeding
in children with hemophilia. A case-crossover study nested within
prospective cohort study design was conducted on 104 schoolchil-
dren. Children with hemophilia were monitored for bleeds up to 1
year. Physical activity was assessed according to expected frequency
and severity of collisions. The risk of bleeds associated with phys-
ical activity was estimated 8 hours before the bleed and two times
for 8hour control window. Children with hemophilia were more ex-
posed to the risk of bleeding in vigorous physical activity.
Cohort Studies identify a group of people and follow them for some
time with a desire to see how their exposures affect their outcomes
and are normally used in cases that cannot be controlled experi-
mentally. Cohort studies are the only ones of observational stud-
ies that can calculate cumulative incidence and an incidence rate
(Rothman et al., 2008; Ahrens & Pigeot, 2005; Aschengrau & Seage,
2013) between prospective and retrospective studies. Prospective
study design watches for outcome during the period of study and
involves observation of subjects over a long period and is con-
sidered as a gold standard of observational research (Aschengrau
& Seage, 2013). Maffeis, Talamini, and Tato (1998) researched the
influence of diet, physical activity and parents’ obesity on children’s
adiposity. Anthropometric measures of 112 prepubertal children
were initiated in 1992 and follow-up measurements in 1996. Obesity
was defined as relative body mass index > 120%. Parents’ obesity
was the main risk factor for childrens’ obesity and sedentary be-
havior was independently associated with overweight at the age of
65
Case-Crossover Study Design. Case-crossover studies are retrospect-
ive and the case serves as his/her own control for some compar-
ison issues (Woodward, 2013). These studies are good where the
outcome is acute and well defined (Rothman et al., 2008). The dis-
advantage of case-crossover studies is risk for having recall bias.
Case-crossover studies require careful selection of period and care-
ful selection of timing and the length of the windows. Experience
has shown that case-crossover design applies best if the exposure
is intermittent (Maclure & Mittleman, 2000). Broderick et al. (2012)
searched associations between physical activity and risk of bleeding
in children with hemophilia. A case-crossover study nested within
prospective cohort study design was conducted on 104 schoolchil-
dren. Children with hemophilia were monitored for bleeds up to 1
year. Physical activity was assessed according to expected frequency
and severity of collisions. The risk of bleeds associated with phys-
ical activity was estimated 8 hours before the bleed and two times
for 8hour control window. Children with hemophilia were more ex-
posed to the risk of bleeding in vigorous physical activity.
Cohort Studies identify a group of people and follow them for some
time with a desire to see how their exposures affect their outcomes
and are normally used in cases that cannot be controlled experi-
mentally. Cohort studies are the only ones of observational stud-
ies that can calculate cumulative incidence and an incidence rate
(Rothman et al., 2008; Ahrens & Pigeot, 2005; Aschengrau & Seage,
2013) between prospective and retrospective studies. Prospective
study design watches for outcome during the period of study and
involves observation of subjects over a long period and is con-
sidered as a gold standard of observational research (Aschengrau
& Seage, 2013). Maffeis, Talamini, and Tato (1998) researched the
influence of diet, physical activity and parents’ obesity on children’s
adiposity. Anthropometric measures of 112 prepubertal children
were initiated in 1992 and follow-up measurements in 1996. Obesity
was defined as relative body mass index > 120%. Parents’ obesity
was the main risk factor for childrens’ obesity and sedentary be-
havior was independently associated with overweight at the age of
65
