1. What demographic variables were measured at the nominal level of measurement in the Oh et al. (2014) study? Provide a rationale for your answer.
Nominal data comprises of data which are in the form of a list, name or information that cannot be separated into discrete categories. The nominal demographic variables measured in this case were regular exercise, Non-smoker, No-drinker and history of fracture. Also, bone mineral density was measured and nominally categorized as osteoporosis, normal or osteopenia. These measures are nominal as their answers cannot be represented by numbers.
Delegate your assignment to our experts and they will do the rest.
2. What statistics were calculated to describe body mass index (BMI) in this study? Were these appropriate? Provide a rationale for your answer.
In this study, the statistics used in calculation of BMI were height and weight. BMI is calculated by divided weight (in kilograms) by height in meters squared. This study utilized centimeters in measuring height which can easily be converted to desired units (meters). The statistics were appropriately used in the study.
3. Were the distributions of scores for BMI similar for the intervention and control groups? Provide a rationale for your answer
Yes, the distribution scores between the two groups were similar. The control group had a mean BMI of 23.38 (SD=3.32) and the intervention group had a mean BMI of 24.17 (SD=2.5). However, the standard deviation indicate a significant overlap between the two means while t-test of chi-squared score shows no significant difference (p<0.05).
4. Was there a significant difference in BMI between the intervention and control groups? Provide a rationale for your answer.
There was no significant difference between the two groups. The conclusion of the study states that “there were no differences in the baseline characteristics of the groups”. Additionally, taking the t-score from table two and calculating with 40 degrees of freedom (DF=N-1), the p-value is obtained as 0.485. This is less than 0.5 and hence there is no significant difference between the two groups in this study.
5. Based on the sample size of N = 41, what frequency and percentage of the sample smoked? What frequency and percentage of the sample were non-drinkers (alcohol)? Show your calculations and round to the nearest whole percent.
Of the total sample size of 41, there was no smoker. This implies that the percentage of those who smoked was 0% i.e., 0/41 ×100= 0% hence the frequency is also zero. On the other hand, 40 participants were non-drinkers while only one was a drinker. This implies that the percentage of non-drinkers is 98% i.e.
40/41 ×100 = 98%.
6. What measurement method was used to measure the bone mineral density (BMD) for the study participants? Discuss the quality of this measurement method and document your response.
Bone mineral density was measured using dual energy x-ray absorptiometry (DEXA) scanning. The quality of this measurement method is reliable and of high quality standards as the error rate for these scans is less than 1%.
7. What statistic was calculated to determine differences between the intervention and control groups for the lumbar and femur neck BMDs? Were the groups significantly different for BMDs?
The statistic calculated to rule out the difference between control groups and intervention group for femur neck and lumbar was the mean of the BMD. To calculate the significance difference, t-test on difference between means was conducted. The differences were not significant as the t-values for intervention and control group being 0.0526 and 0.055 respectively.
8. The researchers stated that there were no significant differences in the baseline characteristics of the intervention and control groups (see Table 2). Are these groups heterogeneous or homogeneous at the beginning of the study? Why is this important in testing the effectiveness of the therapeutic lifestyle modification (TLM) program?
These groups are homogenous at the beginning of the study because the study quotes that baseline characteristics between these two groups were not significantly different. This is particularly important for testing TLM because heterogeneous groups will provide inaccurate result as the differences in their factors could play a role in BMD rather therapeutic lifestyle modification itself.
9. Oh et al. (2014, p. 296) stated that “the adherence rate to the TLM program was 99.6%.” Discuss the importance of intervention adherence, and document your response.
Adherence to a program is critical as it has a substantial impact on statistical power and interpretation of the entire study. Non-adherence among participants to a program ruins the reliability and credibility of the data obtained in such a trial. This under powers the results and the contrast between similar studies is inhibited. In other words, intervention adherence is important for obtaining accurate and reliable data thus enabling derivation of a solid conclusion.
10. Was the sample for this study adequately described? Provide a rationale for your answer. (Grove 97-106)
In my opinion, the sample for this study was not completely described. The researcher in this study provides information on height, weight, age, BMI and some measures of lifestyle. However, there exist some other characteristics that could have been utilized as baseline information so as to improve the findings. A good example, is the incorporation of race as a baseline characteristic. Additionally, the researcher did not also describe what the control group did in contrast to the intervention group.
