When Non-Significant Results Can Mask Significant Results-A Procedure for Using Dose-Related Analyses
Gilbert R Kaats1*, Mrvichin NA1, Nugent SD2, Preuss HG3
1Integrative Health Technologies,Inc.,San Antonio, USA
2Mannatech Inc.,Coppell, USA
*Corresponding author: Gilbert R Kaats, Integrative Health Technologies, Inc., San
Antonio, USA. Tel: +12108244200;
+12108612400; Fax: +12103906142; Email: grk@ihtresearch.com
Received Date: 27 July, 2017; Accepted Date: 09 September, 2017; Published Date: 15 September, 2017
Citation: Kaats GR, Mrvichin NA, Nugent SD, Preuss HG (2017) When
Non-Significant Results Can Mask Significant Results – A Procedure for Using
Dose-Related Analyses. Food Nutr J 2: 144. DOI: 10.29011/2575-7091.100044
Background: Non-significant
within-group and between-group comparisons of baseline-ending changes in
clinical trials and pilot studies can mask positive changes if dose-related
compliance procedures are not applied.
Objective: To provide examples of three studies in which
between- and within-group analyses of changes from baseline suggested minimal
or no efficacy in contrast to dose-related procedures that suggested otherwise.
Methods: Data were obtained from three unpublished
clinical or pilot studies in which between-group and within-group analyses
suggested the absence of, or minimal, efficacy.
Data from these three studies were re-analyzed using a dose-related
procedure based on study participants’ compliance with product-usage
requirements. Using compliance ratings,
data were sub-grouped by quartiles or the median of the amount of product
usage.
Results: In all three studies
within-groups t-tests suggested there were minimal or non-significant changes
from baseline and no significant differences between the active and placebo or
control groups. However, using product
consumption procedures revealed significant differences between upper and lower
quartiles and between above and below the medians of product usage. No similar differences were found in either
the placebo or control groups when the compliance procedures were applied
suggesting the findings was not a reflection of subjects’ motivation.
Conclusions: Incorporating the
dose-related procedures into study protocols can lead to an increased
understanding of treatment plans or interventions.
Keywords: Compliance;
Dose-related
1. Introduction
In many pilot and clinical trials, the significance levels of
within and between-group analyses are used as the basis of decisions regarding
the safety and efficacy of the product being tested. However, notwithstanding
these outcomes, additional within-group dose-related analyses are often
available, but overlooked. In some cases, these analyses can increase the
confidence in product’s efficacy, particularly when using small study groups.
Dose-related within-group analyses can also provide useful information with
regard to the accuracy of pre-established dose levels. Conversely, in instances
where between- and within-group analyses have shown negative results,
additional dose-related analyses may suggest that the failure of the product to
demonstrate efficacy was the result of poor subject compliance as opposed to a
lack of efficacy. A number of studies have suggested that subjects often
overstate their product usage for a variety of reasons, not the least of which
is a desire to please the researcher or concern that they will not receive the
incentive fees for participation in the study if they fail to take the product
as prescribed. Thus, the inaccuracy of subject self-reports can undermine the
validity of within and between group comparisons. In studies in the US, poor
compliance has been associated with increased health care costs and risk of
hospitalization [1], particularly when the underlying problem is difficult
if not impossible for the subject or patient to receive timely feedback on
progress or lack of progress. After three decades of
study [2], concluded that in spite of continuing efforts, “… no
substantial new insights have arisen from quantitative research of compliance
and methods for measuring remain inadequately addressed.” [3] are
more hopeful concluding that “Even with high rates of noncompliance,
experimental data can yield useful and something accurate information on the
effects of a treatment on the population” and offer statistical formulas for
adjusting for non-compliance.
This study reports re-analyses of three studies in which
the between- and within-group analyses suggested weak or no significant
efficacy and dose-related analyses suggested otherwise and the method used to
enhance subject compliance with product usage reporting. In all three studies,
the procedures described below followed the guidelines set forth
earlier [4] to improve candid end-of-study product usage reports.
2. Method
During the process of giving informed consent, subjects were
explained that while they would receive a fee for their participation, the fee
was not an “Incentive fee” but rather a “Recording fee” for timely recording
their actual product usage and discomfort they might attribute to the
product. As such, subjects were advised, that while we encouraged
taking the product as prescribed, at least equally important is their candid
recording of how much or how little product they actually consumed. Throughout
the three studies reviewed below, subjects were reminded of this distinction
between “Incentive” and “Recording” fees and that their fees would be paid at
the end of the study irrespective of the amounts of product usage and that
proportional fees would be paid even if the subject withdrew from the study. At
the conclusion of the study comparisons were made of changes from baseline in
body composition measures: Scale Weight (SW), Fat Mass (FM) and Fat-free Mass
(FFM) and a Body Composition Change Index (BCCI). The BCCI is based on the
assumption that reductions in FM and gains in FFM signified positive changes
and were scored accordingly. Conversely, increases in FM and decreases in FFM
were assumed to be negative changes and were scored accordingly. The
BCCI is the net sum of these positive and negative outcomes. Additional
information on the BCCI is provided elsewhere. Since there were no changes in
height in these short-time studies, changes in the BMI were identical to
changes in scale weight (Correlating 0.998) and are not
reported. Using the subjects’ product usage reports, within-group
comparisons were made between subjects above and below the median of product
usage and in quartiles. The three studies shown below. All three studies were
approved by the Solutions Institutional Review Board, 16609 Cantrell Road Ste
15a, Little Rock, AR., 72223 and were conducted in accordance with the
provisions of the World Medical Association’s Declaration of Helsinki.
3. Results
Study group 1
Subjects in this group consumed a dietary supplement
designed to facilitate positive changes in body composition over a 60-day study
period. Using subjects’ product usage reports was for the first
study, “Compliant” subjects where those who were above the median self-reported
compliance with product usage requirements. “Partially Compliant”
for those who were below the median of product usage. Using the number of
capsules subjects reported during the study, subjects were classified either as
“Compliant” or “Partially Compliant” based whether or not their product usage
was above or below the median product usage report for the study cohort.
Comparisons between the two groups are shown in (Table
1) below. As shown on the “Total Caps” line, there was a statistically
significant (p<0.001) between subjects above the median (n=9) and those
below the median (n=11). As the comparisons between the partially
compliant and compliant reveals, there were no differences between the two
groups with regard to overall weight loss. However, the Compliant group had a
three-fold greater reduction in % fat (P=0.03) and FM (p=0.04). Although the
Partially Compliant group lost FFM (-0.1 lbs.), the Compliant group gained FFM
(+1.2 lbs.), although this difference failed to reach statistical significance
(p=0.27). Similarly, the compliant group’s BCI was 6 times greater
than the Partially Compliant group (+0.5 lbs. vs. + 3.0
lbs.). However, the difference failed to reach statistical
significance (p=0.27).
4. Conclusion
Poor adherence to anti-osteoporotic therapy significantly
increases the risk of morality, possibly due to an increased risk of infection.
Efforts should be made to improve adherence.
This study investigated the effects of 1st-year
adherence to anti-osteoporotic treatment on the risk of mortality in patients
with magnetic resonance imaging-proven acute osteoporotic vertebral fractures
after vertebra plasty. Poor adherence to anti-osteoporotic therapy
significantly increases the risk of morality, possibly due to an increased risk
of infection. Efforts should be made to improve adherence.Poor adherence to
medications was significantly associated with an increase in the rate of
infection (HR: 4.56; 95% CI: 1.12-18.52), which was the most common cause of
death.
More recently [5] attempted to assess the effects of
whole grain consumption on changes in body composition finding that the data
did not allow for valid conclusions about the relationship because of poor
compliance. About the role of whole grains and body weight and body
composition. However, they do point out the need for precise biomarkers of food
consumption that would allow for post hoc validation of compliance. Extra
weight should be placed on these measurable “On ensuring compliance to the
recommended diet beyond self-report during the study.”
The aim of this study, therefore, was to determine this study
reports re-analyses of three studies in which the between- and within-group
analyses suggested weak or no significant efficacy and dose-related analyses
suggested otherwise and the method used to enhance subject compliance with
product usage reporting. In all three studies, the procedures described below
followed the guidelines set forth earlier [4] to improve candid
end-of-study product usage reports.
Figure 1: Comparison of changes in body composition above and below
the median of amount of product consumed during study period.
- Halpern R, Becker L, Iqbal SU, Kazis LE, Macarios D, et al. (2011) The association of adherence to osteoporosis therapies with fracture, all-cause medical costs, and all-cause hospitalizations: a retrospective claims analysis of female health plan enrollees with osteoporosis. J Manag Care Pharm17: 25-39.
- Vermeire E, Hearnshaw H, VanRoyen P, Denekens (2001) J Patient adherence to treatment: three decades of research. A comprehensive review Journal of Clinical Pharmacy and Therapeutics 26: 331-342.
- Balke A, Pearl J (2011) Bounds on Treatment Effects from Studies with Imperfect Compliance. Department of Statistics Papers.
- Kaats GR, Preuss HG (2012)Challenges to the Conduct and Interpretation of Weight Loss Research: Reflections on 35 Years of Weight Loss Research. In Bagchi D, Preuss HG. (eds.) “Obesity: Epidemiology, Pathophysiology and Prevention. 2nd edition, CRC Press Taylor & Francis Group. Pg No: 813-850.
- Kristensen M, Pelletier X, Ross AB, Thielecke F (2017) A High Rate of Non-Compliance Confounds the Study of Whole Grains and Weight Maintenance in a Randomised Intervention Trial-The Case for Greater Use of Dietary Biomarkers in Nutrition Intervention Studies. Nutrients 9: 55.