Treatment of Obesity in Underserved Rural Settings (TOURS): Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Treatment of Obesity in Underserved Rural Settings (TOURS) (NCT00201006), a randomized na study. The primary outcome is Change in Body Weight..

2. Clinical Question

The clinical question is about the comparative results of three approaches to delivering weight-management support in the study population. It is not a comparison with no contact or with usual care: each group received an intervention, although the amount and mode of contact differed. The posted primary outcome is a continuous measure of body-weight change, and the results are reported as group means with standard errors.

The registry does not provide further detail about the intended direction of the treatment contrast, additional eligibility requirements, or how participants were recruited. It also does not report outcomes beyond the primary measure in the posted results. The available comparison estimates therefore address group mean changes in body weight, rather than other possible outcomes or the experience of every participant.

3. Trial Design

Treatment of Obesity in Underserved Rural Settings (TOURS) is recorded as a randomized, parallel-group trial sponsored by the University of Florida. The registry lists the study status as completed, with enrollment of 234. The recorded start is 2003-06 and the primary completion is 2008-05. The phase is listed as NA.

There were three arms: face-to-face counseling, telephone counseling, and mail contact. The arm descriptions specify 26 biweekly face-to-face group counseling sessions, 26 biweekly telephone counseling sessions, and 26 biweekly newsletters with weight-management advice. Masking is recorded as none. The registry does not report further detail about the randomization procedure, allocation concealment, or whether anyone involved in measurement or analysis was masked.

The primary outcome was change in body weight in kilograms. Its timeframe is described as one year, and the description specifies the 12-month period following completion of a six-month lifestyle treatment. The arm records give sample sizes of 83 for face-to-face counseling, 72 for telephone counseling, and 79 for mail contact. The recorded outcome means are 1.2 kg, 1.2 kg, and 3.7 kg, respectively, each reported with a standard error.

The registry lists one outcome measure and no posted analysis records. It nevertheless contains primary outcome values and comparison estimates. Details of the trial protocol, the sample-size justification, the planned statistical analysis, and any interim analyses are not reported in the registry record. The recorded design supports a comparison of the three randomized groups, but the available record does not establish which additional analyses, if any, were planned or carried out.

4. Participant Flow and Accounting

The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.

Before assignment: 298 women participated in a standard 6-month lifestyle modification program for weight loss, delivered in groups at Cooperative Extension Offices. Eligibility for randomization required completion of the 6-month lifestyle program; 234 completed the initial treatment and were assigned randomly to one of the three extended care conditions.

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: Data from all randomized participants were analyzed according to the Intent to Treatment principle. Missing data (6%) were completed based on known pattern of weight regain (i.e., 0.3 kg per month).

5. Baseline Characteristics

The table reproduces the baseline characteristics posted in the registry, which describe the participants analysed at baseline and help show whether the randomized groups were comparable.

6. Primary Endpoint

The registry lists the primary outcome as Change in Body Weight., measured over one year.

The primary endpoint is the mean change in body weight, measured in kilograms. The registry defines the period as the 12 months following completion of a six-month lifestyle treatment and gives the timeframe as one year. A continuous outcome preserves the amount of change on its measurement scale rather than assigning participants to broad outcome categories. Reporting the group mean gives a summary of the average change in each randomized arm.

This endpoint was chosen in keeping with the stated aim of testing interventions designed to promote long-term weight management. A measurement over the year after the lifestyle treatment focuses on change after the treatment period, rather than only during the six months of treatment. The registry does not describe other dimensions of weight management or explain why this endpoint was selected over possible alternatives.

The posted arm results are means accompanied by standard errors: face-to-face counseling, 1.2 kg (standard error 0.6); telephone counseling, 1.2 kg (standard error 0.7); and mail contact, 3.7 kg (standard error 0.7). The registry describes missing outcome data for 6% of participants and says those values were completed using a stated pattern of weight regain. It does not report individual participant trajectories, the distribution of changes, or additional endpoint details such as measurement procedures.

7. Results Posted in the Registry

• Telephone Counseling: mean 1.20 versus 1.20 on control; difference 0.00 (95% CI -1.81 to 1.81), standardized effect d = 0.00; z-test p = 1.000.
• Mail Contact: mean 3.70 versus 1.20 on control; difference 2.50 (95% CI 0.69 to 4.31), standardized effect d = 0.43; z-test p = 0.007.

8. Statistical Interpretation

9. Statistical Methods Explained

For a continuous outcome such as body-weight change, a group mean summarizes the central average on the measurement scale. The registry reports each arm's mean and standard error. A standard error describes the statistical uncertainty around an estimated mean; it is not the same as the spread of individual observations. The registry does not post standard deviations for the arm-level endpoint.

What does a mean difference represent?

A mean difference compares the average outcome in one group with the average in another. The posted comparisons use face-to-face counseling as the reference. The telephone-counseling estimate is 0.0 kg, and the mail-contact estimate is 2.5 kg. These estimates are in kilograms, the same scale as the endpoint. The comparison summarizes the difference in group means; it does not say that every participant in one group had a particular result relative to every participant in another.

Randomization is intended, in general, to make treatment groups comparable on average at the start of a study. It does not guarantee that all characteristics will be identical across groups, and the registry does not report baseline characteristics or the allocation procedure. A parallel-group design assigns participants to one intervention group and compares outcomes across those groups. No masking is recorded, so participants and study personnel were not masked according to the registry's design entry.

How should an interval estimate be read?

In general, a confidence interval expresses uncertainty around an estimated quantity: intervals that are narrower indicate greater precision on the same scale, while wider intervals indicate less precision. The registry posts intervals for the two mean differences. For telephone counseling compared with face-to-face counseling, the interval runs from -1.807 to 1.807 kg. For mail contact compared with face-to-face counseling, it runs from 0.693 to 4.307 kg. The confidence level used for these intervals is not reported in the registry record, so it should not be assumed from the interval alone.

Whether an interval includes zero is relevant when interpreting a difference because zero represents no difference between group means. The telephone comparison interval includes zero; the mail-contact comparison interval does not. This is a statement about the posted estimates and intervals, not proof that an effect is absent or present in every setting. The interval also does not convey the clinical importance of the difference without a meaningful threshold, which is not reported.

What does the p-value add?

In general, a p-value describes how compatible observed data are with a specified statistical null model. It does not measure the probability that the null hypothesis is true, and it does not quantify the size or practical importance of a difference. The posted unadjusted p-values are 1.0 for telephone counseling versus face-to-face counseling and 0.007 for mail contact versus face-to-face counseling. The registry does not report whether these p-values are from the trial's original statistical analysis or give further model details. It also does not report a multiplicity adjustment.

The record includes a planning illustration for the mail-contact comparison, based on the observed effect. The assumptions state a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation. The planning rows consider 100%, 75%, and 50% of the observed effect, with participants per arm listed for 80% and 90% power. These are planning illustrations, not observed power and not evidence about the probability that the study detected an effect. They are not reported as the trial's own design justification.

Why do assumptions matter?

Statistical methods rely on assumptions about the outcome and the way data were collected. For continuous measures, a method that uses means and standard errors summarizes uncertainty around averages; a full assessment may also depend on the outcome distribution and the statistical model. The registry does not report the model, diagnostics, or any adjustments used for the comparisons. A reader should not infer these details from the posted point estimates and intervals alone.

Missing data are another methodological consideration. The registry says 6% of the primary outcome data were missing and completed based on a known pattern of weight regain, specified as 0.3 kg per month. In general, imputation fills in missing values according to an assumption or model, and the results can depend on that choice. The registry does not report sensitivity analyses or the details needed to independently evaluate the imputation. It describes the analysis population as all randomized participants according to the Intent to Treatment principle, but does not provide additional implementation details.

The number of outcome measures and the number of posted analysis records are not the same thing. The registry lists one outcome measure and zero analysis records, while also showing outcome values and comparison results. That combination means the posted results are present, but separate analysis records and fuller statistical methods are not. Details such as the original analysis plan, interim analyses, and sample-size justification are not reported in the registry record.

10. Confidence Intervals and Precision

Precision concerns how much uncertainty surrounds an estimate. For a mean difference, the point estimate gives the central reported contrast, while an interval shows a range of values compatible with the analysis under its assumptions. The posted interval for telephone counseling versus face-to-face counseling extends from -1.807 to 1.807 kg around the 0.0 kg estimate. The interval includes zero and allows for differences in either direction.

For mail contact versus face-to-face counseling, the reported estimate is 2.5 kg and the interval extends from 0.693 to 4.307 kg. This interval does not include zero. It still spans a range of possible differences, so the estimate should not be read as an exact value. The confidence level associated with these intervals is not reported in the registry record. The interval calculations also cannot be fully assessed from the record because the analysis model and other technical details are not reported.

Standard errors for the arm means are 0.6 kg for face-to-face counseling, 0.7 kg for telephone counseling, and 0.7 kg for mail contact. These quantify uncertainty in the estimated means, not the variability of outcomes among individual participants. The registry does not post standard deviations for the endpoint. It also does not provide a clinically important difference threshold, so statistical precision cannot be translated into a judgment about practical importance from the registry record alone.

Interval width and p-values are related aspects of inference, but neither substitutes for knowing the design, analysis assumptions, and population. The comparisons are unadjusted, and the record does not report a multiplicity procedure. The posted estimates offer a measure of precision for the stated comparisons, while the missing methodological details limit how completely that precision can be assessed.

11. Multiplicity, Missing Data and Analysis Populations

The registry lists one outcome measure, the change in body weight. It reports two comparisons against face-to-face counseling: telephone counseling and mail contact. The corresponding p-values are unadjusted. The registry does not report a multiplicity correction, a prespecified comparison hierarchy, or whether additional comparisons were planned. Without those details, the record does not establish how the possibility of multiple statistical tests was handled in the study's original analysis.

The primary outcome description states that data from all randomized participants were analyzed according to the Intent to Treatment principle. The registry reports that missing data comprised 6% and says they were completed based on a known pattern of weight regain, namely 0.3 kg per month. The posted means and comparisons therefore reflect an analysis that includes imputed values, as described in the record. The registry does not report the number of missing values in each arm or explain in detail how the pattern was applied to individual participants.

In general, missing-data methods rely on assumptions about the unobserved outcomes. Different assumptions can lead to different estimates, which is why sensitivity analyses can be useful. Sensitivity analyses are not reported in the registry record. The record also does not provide enough information to evaluate the imputation procedure independently or to determine whether any alternative approaches were examined.

The registry lists zero analysis records even though the primary outcome and comparisons are posted. It does not report a full statistical analysis plan, interim analyses, or a sample-size justification. As a result, the extent to which the posted comparisons match a prespecified plan is not reported in the registry record. The planning illustration is based on the observed effect and should not be interpreted as the trial's own sample-size rationale.

12. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 5% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: musculoskeletal injury (16.9%), cardiac symptom (2.8%), neurological symptoms (2.8%), respiratory problem (2.8%), gynecologic and breast problems (2.5%).

The registry reports serious adverse events by group using the number at risk and the number affected. For face-to-face counseling, 83 were at risk and 21 were affected; for telephone counseling, 72 were at risk and 20 were affected; for mail contact, 79 were at risk and 12 were affected. These are counts, not percentages. The registry also lists other adverse events: 19 affected in face-to-face counseling, 9 in telephone counseling, and 12 in mail contact, with the same group-specific numbers at risk as listed for serious events.

The registry lists serious adverse event terms and percentages, including musculoskeletal injury at 16.9%, cardiac symptom at 2.8%, neurological symptoms at 2.8%, respiratory problem at 2.8%, gynecologic and breast problems at 2.5%, and ear problems at 1.4%. It does not report the group attribution or denominator for these listed percentages, nor whether categories can overlap. The death fields are not reported in the registry record; they should not be interpreted as zero deaths.

These safety entries are descriptive counts. The registry does not provide a formal comparative safety analysis or enough detail to infer that differences between group counts were caused by an intervention. The counts should be read with the available denominators and reporting limitations, rather than as a stand-alone comparison of risk.

13. What the Result Does, and Does Not, Mean

The posted primary results describe mean body-weight changes in three randomized groups over the year following completion of a six-month lifestyle treatment. Face-to-face and telephone counseling each had a reported mean of 1.2 kg. Mail contact had a reported mean of 3.7 kg. The telephone-versus-face-to-face estimate was 0.0 kg, with an interval from -1.807 to 1.807 and an unadjusted p-value of 1.0. The mail-contact-versus-face-to-face estimate was 2.5 kg, with an interval from 0.693 to 4.307 and an unadjusted p-value of 0.007.

These statistics describe group averages and their uncertainty, not individual outcomes. They do not indicate that all participants experienced a change equal to their group mean. Nor do they establish the reasons for any observed difference. The registry does not report a threshold for a meaningful difference, so the statistical results alone do not establish practical or clinical importance.

The telephone comparison does not establish equivalence between telephone and face-to-face counseling. The registry does not identify an equivalence or non-inferiority design or a corresponding margin. Likewise, the mail-contact comparison should not be generalized beyond the study context without considering the population, implementation, missing data, and unreported methodological details.

The results do not answer questions about outcomes that were not posted. The registry lists one outcome measure and no secondary outcome results. It also does not report additional participant characteristics, detailed eligibility criteria, intervention adherence, or long-term outcomes beyond the specified measurement period. The adverse-event counts are descriptive and do not by themselves establish comparative safety.

Overall, the record documents the outcome estimates and comparisons but leaves important details of the statistical plan and conduct unreported. The interpretation should remain tied to the stated population of obese women in medically underserved rural counties, the three interventions, and the endpoint and missing-data approach described in the registry.

14. Why This Trial Matters Statistically

This trial is statistically informative because it compares three approaches to delivering weight-management contact within a randomized, parallel-group design. The approaches differ in mode: group counseling in person, counseling by telephone, and newsletters by mail. That structure makes the primary comparison relevant to how the delivery approach relates to average body-weight change in the study population, while keeping the interpretation focused on the interventions actually recorded.

The outcome is continuous and is reported in its original unit, kilograms, with means and standard errors. This makes the group summaries and mean differences directly interpretable on the outcome scale. The posted intervals also make uncertainty visible, rather than relying on a single point estimate. The differing interval results for the two comparisons illustrate why the estimated size of a difference and its precision both matter.

The record is also useful for showing how analysis choices affect interpretation. The primary outcome includes imputed values for missing data, and the registry gives the imputation basis. At the same time, the absence of sensitivity analyses means the robustness of the findings to other assumptions cannot be assessed from the record. The unadjusted comparisons and lack of a reported multiplicity plan are additional considerations when reading more than one comparison.

Finally, the registry makes clear the distinction between an observed study result and a planning calculation. The sample-size illustrations use the observed effect and stated planning assumptions; they are not observed power and are not the trial's own design justification. That distinction helps prevent retrospective calculations from being mistaken for evidence about the study's original planning or ability to detect effects.

15. Limitations

• The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
• Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.

The registry record does not report detailed eligibility criteria, participant characteristics, recruitment procedures, or the randomization method. It records that the trial was randomized and unmasked, but does not provide further information about allocation concealment or masking of outcome measurement and analysis. These omissions limit assessment of how the study was conducted and how closely its participants represent the population named in its objective.

The outcome description identifies body-weight change over a specified follow-up period, but the measurement procedures are not reported. The record gives means and standard errors but does not report the distribution of individual outcomes or arm-level standard deviations. It also does not report a threshold for a clinically important difference. These gaps limit evaluation of outcome variability and the practical meaning of the estimates.

Missing data affected 6% of the primary outcome data and were completed using the stated pattern of weight regain. The registry does not report the arm-specific missing-data counts, full imputation details, or sensitivity analyses. Because results depend in part on the imputation assumptions, the record does not show how the estimates would change under other assumptions.

The registry reports unadjusted comparisons but does not report the statistical model, confidence level, multiplicity approach, or full analysis plan. It lists zero analysis records, no secondary outcome results, and no sample-size justification or interim analyses. The safety entries include group counts and selected serious-event terms, but do not provide a formal comparative analysis or clarify the denominator and group attribution for the listed percentages. Each of these limits narrows what can be concluded from the posted results.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Treatment of Obesity in Underserved Rural Settings (TOURS) — NCT00201006.
• Registry record last updated 2014-03-07; status last verified 2014-01.
• Results first posted 2014-03-07.
• Data retrieved from ClinicalTrials.gov on 2026-11-09.
• Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.

19. Record Summary

The registry record describes a completed, randomized, unmasked, parallel-group study sponsored by the University of Florida, with enrollment of 234. The trial compared face-to-face counseling, telephone counseling, and mail contact for weight management among obese women in medically underserved rural counties. Its primary outcome was mean change in body weight in kilograms during the year following completion of a six-month lifestyle treatment.

The reported arm means were 1.2 kg for face-to-face counseling, 1.2 kg for telephone counseling, and 3.7 kg for mail contact. The posted mean differences were 0.0 kg for telephone counseling versus face-to-face counseling and 2.5 kg for mail contact versus face-to-face counseling. Missing primary outcome data were completed using the described pattern of weight regain. The record also lists adverse-event counts, but full comparative safety details are not reported.

The registry does not report the full statistical plan, sample-size justification, interim analyses, confidence level for the intervals, or sensitivity analyses for missing data. It lists one outcome measure and zero analysis records while displaying outcome results and comparisons.