“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.” by Oh et al.
What were demographic variables measured at the nominal level of measurement in the Oh et al. (2014) study?
Unlike ordinal and interval scales, nominal scales do not provide information about the order of values or interval between them. Nominal scales can only be used for estimating data and applying labels without any numerical significance. The following demographic variables were measured: alcohol consumption, smoking, history of fractures, and daily exercise. Also, bone mineral density (BMD) was measured and distributed along with nominal scales as normal, osteopenia, and osteoporosis.
What statistics were calculated to describe body mass index (BMI) in this study?
Height and weight were used for the body mass index (BMI) calculation in this study. The BMI is a measure of body fat that can be derived through the division of a person’s weight (kg) by their height (m). Even though the group’s height was measured in centimeters, the assessment of the index was appropriate. It has to do with the fact that any measurement of length estimated in centimeters can be easily converted to its equivalent in meters by dividing it by 100. Also, the difference in the indexes between the intervention and control groups was not meaningful.
Were the distributions of scores for BMI similar for the intervention and control groups?
The distribution of scores for BMI was even for the two groups. The statistical BMI means for the intervention and control groups were 24.17 (SD = 2.5) and 23.38 (SD = 3.32). Both means overlapped substantially. Furthermore, there was no statistically significant difference between the t-score and chi-squared score.
Was there a significant difference in BMI between the intervention and control groups?
The researchers did not observe substantial differences in the indexes of the two groups. Also, the value of p, which was calculated with 40 degrees of freedom, was 0.485. Such p-value cannot be considered meaningful.
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)?
Out of 41 participants, 40 women were non-drinkers. Therefore, the percentage of non-drinkers can be calculated as follows: 40/41×100 = 97.6%. However, none of the participants smoked, which allowed calculating the percentage of non-smokers as 100.
What measurement method was used to measure the bone mineral density (BMD) for the study participants?
The bone mineral density (BMD) indexes were obtained through dual-energy X-ray absorptiometry (DXA). The researchers used a DEXXUM T scanner for the measurement, which was reasonable since their observational error rate does not exceed 1 percent.
What statistic was calculated to determine differences between the intervention and control groups for the lumbar and femur neck BMDs?
BMD averages were calculated to find discrepancies in these values between the two groups. The discrepancy between the two means was determined with the help of the t-statistic. The form of the t-statistic criterion was assessed by degrees of freedom. The t-value and p-value were discovered at rates of 0.0526 and 0.958, respectively. However, for t of 0.055, the p-value was 0.956. This result cannot be recognized as meaningful because a statistically significant score for the p-value is 0.05 or 5 percent.
Are the control 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?
The females participating in the study were distributed between the two groups with the help of a random number table. The random selection method was the most suitable for the study because it required the groups to be homogeneous. The researchers established points of difference between the groups, which were not substantial. It was an essential procedure for TLM testing that relied on perfectly homogeneous samples. Heterogeneous samples could have been translated into differences between BMD rates, which could have distorted the results of the TLM intervention.
What is the importance of intervention adherence?
The statistical significance of the study hinged on the rate of adherence to the intervention program. Poor adherence rates could have reduced the statistical significance of the study, thereby undermining the researcher’s efforts. The findings of a study with low adherence rates cannot be considered sufficiently meaningful to influence clinical practices. However, the adherence rates in the study under discussion were 99.6 percent, which shows that almost all participants followed the requirements of the intervention.
Was the sample for this study adequately described?
The following baseline characteristics were height, weight, history of fractures, BMI, smoking and drinking statuses, age, and exercise frequency. It follows that the characteristics of the study’s sample were not adequately described. The description of the sample could have been complemented by the inclusion of other important characteristics, such as race. By doing so, the researchers could have substantially improved the reliability of the study’s results. Also, the sample summary of the two groups and control group procedures could also have been included in the article.