What demographic variables were measured at the nominal level of measurement in the Oh et al. (2014) study?
In the study presented by Oh et al. (2014), several demographic variables were not measured by numbers but were presented at the nominal level, which included other types of measurement. In particular, fractures occurrences, the presence of regular exercises, and the mineral density of bones (normal, osteopenia, and osteoporosis) were considered in this way. The parameters included also drinker/non-drinker and smoker/non-smoker.
What statistics were calculated to describe body mass index (BMI) in this study? Were these appropriate?
In order to determine BMI, Oh et al. (2014) used statistics related to individual’s height and weight. The authors maintained all calculations appropriately even though only weight was traditionally measured in kilograms. They resorted to centimeters when approached people’s height but it should not be treated as a mistake because they are easily changed into meters that are usually used to measure this variable. A simple division by 100 allows perceiving these numbers in meters. Thus, the authors’ conclusion that the intervention and control BMI values did not differ much was trustworthy.
Were the distributions of scores for BMI similar for the intervention and control groups?
There were no significant distributions of scores for the intervention and control groups. In the framework of the t score and the chi-squared score, for instance, similar means were revealed. BMI for the intervention and control groups overlapped, as they were 24.7 (SD = 2.5) and 23.38 (SD = 3.32) accordingly. Finally, the value of p (0.485) was higher than needed for the results to be critical.
Was there a significant difference in BMI between the intervention and control groups?
On the basis of the results of the study, it can be concluded that BMI in the intervention and control groups were similar. No significant difference was observed in the framework of the baseline characteristics. Such claim can be supported by the calculated value of p. Oh et al. (2014) found out that p was 0.485. Such value is non-significant because it should be 0.05 or less for the difference to be important, especially taking into consideration the fact that there were 40 degrees of freedom.
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)?
As the size of the sample was N=41, it means that the number of people who were assessed in the framework of the study was 41. According to Table 2 taken from the article, 40 individuals from the total amount were non-drinkers. This result can be turned into percentages using the following calculation: 40/41*100. Thus, it can be stated that 40 participants can be treated as 97.6%. In addition to that, all 41 individuals were non-smokers. Using the same formula, percentages can be calculated: 41/41*100. Thus, the answer is 100%.
What measurement method was used to measure the bone mineral density (BMD) for the study participants?
In their study, Oh et al. (2014) measured BMD using a scanning method. In particular, DEXA was applied. This kind of measurement is generally believed to be rather reliable, and it is often used by different professionals in medical investigations. It is stated in the article that the rate of error was no more than 1%, which allows claiming that this measurement method has high-quality standards.
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?
In order to determine differences between the intervention and control groups, professionals calculated the mean of the BMD score. It was significant for the study to determine the statistical difference between the two groups. Thus, the t-statistic criterion was approached. In particular, it was considered with degrees of freedom. In the groups, the t-value of 0.0526 was aligned with the p-value of 0.958 while the t-value of 0.055 was aligned with the p-value of 0.956. These results allow claiming that the groups were not significantly different for BMDs because the score of p had not reached 0.05 or less.
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?
As the study conducted by Oh et al. (2014) ended and professionals maintained all concluded that necessary calculations, they concluded that the characteristics of the intervention and control groups remained rather similar with no critical alterations observed. However, this information does not mean that they were homogeneous. The sample was selected randomly and their baseline characteristics turned out to be similar. Their comparison allowed testing TLM. Eventually, those differences found in BMD scores were slightly different but it can be explained by the peculiarities of the participants of both teams but not by the influence of the TLM intervention.
Oh et al. (2014, p. 296) stated that “the adherence rate to the TLM program was 99.6%.”
The adherence rate was critical because its intervention could have had a critical influence on the significance of the results. Its importance can be explained by the fact that it determines the statistical power of the obtained results. Thus, if adherence is low or is not observed at all, statistical power is also rather low, which means that the results are unreliable. In the discussed article, the adherence rate was more than 99%, which allows claiming that the study presented reliable results.
Was the sample for this study adequately described?
Oh et al. (2014) described their sample, considering different characteristics. However, it would be better if they provided more details to make the description complete and adequate. In particular, the professionals focused on people’s weight and height, as they determined their BMI, on age and smoking/drinking habits, and finally on fraction history. In the framework of this research, it would be advantageous to get to know people’s race, for instance, because it is known to have influence on the BMD. In addition to that, it would be better if the professionals discussed what was experienced by the control group instead of the intervention because these procedures might have affected their condition as well.
Reference List
Oh, E. G., Yoo, J. Y., Lee, J. E., Hyun, S. S., Ko, I. S., & Chu, S. H. (2014). Effects of a Three-Month Therapeutic Lifestyle Modification Program to Improve Bone Health in Postmenopausal Korean Women in a Rural Community: A Randomized Controlled Trial. Research in Nursing & Health, 37(4), 292–301.