Researchers have suggested that sleep apnoea (the tendency to occasionally stop breathing when asleep) may worsen the effects of allergen-induced asthma. To investigate this possibility, Johnson and colleagues (2015), compared two groups of rats, a normal healthy non-allergic group, and a second group that were mildly allergic to ovalbumin. They subjected these rats to one of two treatments – 1) a 10-minute period of induced hypoxia (oxygen down to 10% of the air), representing the kind of temporary hypoxia that sufferers of sleep apnoea may be subjected to, and 2) a control (normal air) group. They then compared the respiratory function of both groups in these two treatments by using a two-factor ANOVA. (Questions are on the next page).
Researchers have suggested that sleep apnoea (the tendency to occasionally stop breathing when asleep) may worsen the effects of allergen-induced asthma. To investigate this possibility, Johnson and colleagues (2015), compared two groups of rats, a normal healthy non-allergic group, and a second group that were mildly allergic to ovalbumin. They subjected these rats to one of two treatments – 1) a 10-minute period of induced hypoxia (oxygen down to 10% of the air), representing the kind of temporary hypoxia that sufferers of sleep apnoea may be subjected to, and 2) a control (normal air) group. They then compared the respiratory function of both groups in these two treatments by using a two-factor ANOVA. (Questions are on the next page).
Source |
df |
F |
P |
Rat type |
1 |
21.88 |
<0.0001 |
Oxygen treatment |
1 |
141.13 |
<0.0001 |
Rat type x oxygen treatment |
1 |
15.68 |
<0.001 |
Residual |
36 |
|
|
- What is the result of the test of the interaction effect from this analysis?
- What would be the most correct interpretation this result, based on the plot of means?
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