## 4.1 Quick revision

We recommend trying these Quick revision questions before your tutorial.

A study of obstructive sleep apnoea (OSA) in adults with Down Syndrome had $$n = 60$$ adults (27 females; 33 males) undergo a sleep study. The data are shown in Fig. 4.1.

FIGURE 4.1: The Obstructive sleep apnoea data set

1. What would be an inappropriate numerical summary for the age of the participants?
2. What might be an appropriate way to numerically describe the amount of variation in the ages of participants?
3. What might be an appropriate way to numerically describe the average REI of participants?
4. What might be an appropriate way to numerically describe the gender of the participants?
5. In the sample, what percentage of individuals are females?

Progress:

1. Age is quantitative, so odds are not appropriate (odds are used with qualitative data).
2. Variation is measured using standard deviation or IQR.
3. The average value (of a quantitative variable) can be described using a mean or a median.
4. Percentages or odds can be used to numerically summarise a qualitative variable like gender.
5. $$27/60\times 100 = 45$$%.

### References

de Carvalho AA, Amorim FF, Santana LA, de Almeida KJQ, Santana ANC, Neves F de AR. STOP-Bang questionnaire should be used in all adults with Down Syndrome to screen for moderate to severe obstructive sleep apnea. PloS ONE. 2020;15(5):e0232596.