Pilot Project of Health Promotion for People With Diabetes: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Pilot Project of Health Promotion for People With Diabetes (NCT00970294), a na na study. The primary outcome is Recruitment, Retention, Adherence.

2. Clinical Question

In practical terms, the study was intended to gather preliminary information about whether an intensive, customized health promotion program could be delivered to people with type 2 diabetes and to assess outcome measures following participation. The stated aim included obtaining effect-size information for future studies. The registry also lists aerobic fitness and glycemic control as secondary outcomes, but their results are not reported in the registry record.

Because no comparator is recorded, the central question is not whether the program outperformed another intervention or usual care. The primary outcome instead concerns completion among participants who enrolled. Without numerical outcome results, the registry record cannot establish how many participants completed the program or what changes, if any, occurred in aerobic fitness or glycemic control.

3. Trial Design

This was a completed, single-group behavioral intervention study, with 11 participants enrolled. The registry identifies the intervention as a Health Promotion Program and lists no separate comparison group. Allocation is recorded as NA, and masking is recorded as NONE. The phase is recorded as NA. These registry entries describe the study as recorded; they do not supply a more detailed protocol or explain the rationale for these design choices.

The study summary describes a 10-week program for adults with type 2 diabetes, scheduled at a frequency of 3-4 days per week. Program components included aerobic and strength training exercises with a schedule of progression, individual nutrition counseling, and diabetes health education sessions. The arm description further characterizes the activities as supervised exercise, educational sessions, and dietary counseling.

The registry lists the study start as 2007-07 and primary completion as 2008-05, and its status is COMPLETED. These entries identify the recorded study timeline and status; they do not report participant-level follow-up or the timing of each outcome assessment. Details such as the setting, eligibility criteria, recruitment methods, intervention attendance rules, and specific exercise progression are not reported in the registry record.

The primary outcome is titled Recruitment, Retention, Adherence, with a timeframe of 10 weeks and a description focused on the percentage of enrolled subjects who completed the trial. Aerobic Fitness and Glycemic Control are listed as secondary outcomes. The record indicates 3 outcome measures, but it does not provide numerical outcome findings or explain how the secondary outcomes were measured.

A single-group design can describe feasibility and outcomes among participants who take part, but it cannot directly distinguish program-associated change from other influences over time. With no comparator group recorded, any change measured during the program would not by itself establish what would have happened without the intervention. The registry record does not report a statistical analysis plan, a sample-size justification, interim analyses, or analysis populations.

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.

Overall Study

Reasons for not completing this period:

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 Recruitment, Retention, Adherence, measured over 10 weeks.

The primary outcome is titled Recruitment, Retention, Adherence. Its description defines the reported measure as the percentage of enrolled subjects who completed the trial, with a timeframe of 10 weeks. Completion is a practical feasibility outcome: it indicates whether enrolled participants remained through the study period according to the trial’s completion definition. Such information can help assess whether a program is deliverable and can inform the planning of later research.

The title refers to recruitment, retention, and adherence, but the registry’s specific outcome description refers to completion among enrolled subjects. The record does not give separate operational definitions or numerical findings for recruitment and adherence. Nor does it report the number of participants who completed the trial, a percentage, or a measure of uncertainty. The endpoint’s denominator is described as enrolled subjects, but details about how completion was determined are not reported in the registry record.

Completion should not be confused with aerobic fitness or glycemic control. Those are listed as secondary outcomes, and their results are not reported in the registry record. Even a completion measure alone would describe participation and follow-through, not the health effects of the program. Since no comparator is recorded, and the observed completion result is absent, the registry record does not quantify either feasibility or changes in health outcomes.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

Statistical interpretation begins by distinguishing study design, outcome definition, and outcome estimate. The design determines what kinds of comparisons are available. The outcome definition states what was to be measured. The estimate is the numerical result calculated from participants’ observations. For this study, the registry describes a single-group program and identifies completion percentage as the primary outcome, but does not report numerical estimates or analyses. The design and endpoint can be described; the missing estimates cannot be reconstructed from the enrollment count.

What does a single-group design allow?

In a single-group study, observations concern participants who receive the intervention. If outcomes are measured at different times, a within-person comparison may describe change over time. Such a comparison does not provide the same evidence as a concurrent control group: it cannot directly show how outcomes would have changed over the same period without the program. General influences such as ordinary fluctuation, external events, and measurement error can contribute to observed change. These are general design considerations, not claims about what occurred in this study.

Here, the registry record does not report numerical before-and-after results for aerobic fitness or glycemic control. It also does not specify the measurement schedule for these outcomes. Consequently, neither the size nor direction of change can be evaluated. A stated aim to gather preliminary data or estimate effects for future research is not itself evidence that an effect estimate was reported.

How should a completion percentage be interpreted?

A percentage of enrolled participants who completed a study is a descriptive feasibility measure. It relates the number meeting the completion definition to the enrolled group. Its interpretation depends on a clearly defined completion rule, the denominator, and the number meeting that rule. The record identifies enrolled subjects as the reference group, but does not state the observed number completing, the calculated percentage, or detailed completion criteria. No numerical percentage should therefore be inferred from enrollment alone.

Completion also differs from attendance or adherence. A participant might meet a study’s completion definition without attending every scheduled activity, depending on the protocol. The registry record does not give a separate adherence definition or numerical adherence finding. The outcome title includes recruitment and adherence, but the stated outcome description specifically defines completion. This distinction matters when assessing feasibility: enrollment, remaining in follow-up, and participating in intervention activities are related but not interchangeable measures.

What does statistical uncertainty mean?

In general, a confidence interval describes a range of values compatible with the data under a specified statistical method. It communicates precision as well as the estimated outcome. A narrow interval generally indicates greater precision than a wide interval, while both the estimate and interval depend on the design and assumptions. No confidence interval or other uncertainty estimate is reported in the registry record for this study. The enrollment count alone does not determine an outcome interval; the observed outcome data and an appropriate method are also needed.

A p-value, when used, describes how incompatible data are with a specified null model under the test’s assumptions. It is not a measure of clinical importance and does not establish that an effect is real or absent. No p-value or statistical test is reported in the registry record. With no reported outcome estimate, a statistical significance interpretation is not possible.

Why do outcome distributions matter?

General statistical methods should match the type and distribution of an outcome. A completion percentage is based on a binary classification, such as completed or did not complete, and is commonly described with a proportion and an uncertainty estimate. Continuous measures of fitness or glycemic control instead require summaries suited to their scales and distributions. If observations vary more than a chosen model expects, over-dispersion can make standard errors too small and uncertainty appear narrower than warranted. Analysts may then need a model that accounts for the extra variation. This is a general point; the registry record does not identify the outcome distributions or the analysis methods used.

For a single-group design, methods may also need to account for repeated measurements on the same participants if measurements were taken over time. Repeated observations from one person are generally related, rather than independent. The registry does not report whether repeated measurements were collected or how any within-participant correlation was handled. No particular model, test, transformation, or variance adjustment can be attributed to this study.

What can planning calculations tell us?

Sample-size calculations are planning tools. They use assumptions about the effect to detect, variability, significance level, allocation, and chosen statistical method to illustrate how much information a future study might need. They are not observed outcomes and are not a measure of the probability that a completed trial has demonstrated an effect. The registry record includes planning assumptions framed around a two-arm comparison, equal allocation, a two-sided significance level of 0.05, and a normal approximation. It also describes the effect to detect as a fraction of an observed effect.

Those assumptions do not constitute a documented design justification for this single-group study. The registry record does not report a sample-size justification or the observed effect estimate needed to interpret effect-based planning. A two-arm planning setup also does not map directly onto the recorded single-group design. No numerical planning requirements can be interpreted from the outcome data because numerical outcome estimates are not reported in the registry record. Such calculations should be treated as illustrations for planning, not observed power or proof of an intervention effect.

Finally, statistical analysis requires clarity about which participants and observations were included, how missing data were handled, and whether the analysis followed a prespecified plan. Those details are not reported in the registry record. Since the record reports 0 analyses, it does not support a reconstruction of the analysis procedure. The appropriate conclusion is limited: the registry defines intended outcomes and study structure, but does not provide results sufficient for statistical inference.

10. Exact Estimates for Each Arm

No two-arm comparison is shown for this trial, but each arm's result can still be summarized with exact interval estimates computed from the posted counts. The Clopper-Pearson interval is exact and conservative; the Wilson interval is a common closer-to-nominal alternative; the Bayesian credible interval uses a uniform Beta(1, 1) prior. For small groups the three can differ noticeably.

R code and output

arm    <- c("Health Promotion Program")
n      <- c(11)
events <- c(6)
for (i in seq_along(n)) {
  ci <- binom.test(events[i], n[i])$conf.int          # Clopper-Pearson exact interval
  cr <- qbeta(c(0.025, 0.975), 1 + events[i], 1 + n[i] - events[i])   # Bayesian, uniform Beta(1,1) prior
  wi <- (function(x, n) { p <- x / n; z <- qnorm(0.975); d <- 1 + z^2 / n
    c((p + z^2 / (2 * n) - z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d, (p + z^2 / (2 * n) + z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d) })(events[i], n[i])
  cat(sprintf("ARM|%s|%d|%d|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f\n", arm[i], n[i], events[i], 100 * events[i] / n[i],
              100 * ci[1], 100 * ci[2], 100 * wi[1], 100 * wi[2], 100 * cr[1], 100 * cr[2]))
}

ARM  Health Promotion Program  11  6  54.5  23.4  83.3  28.0  78.7  27.7  78.9

11. Multiplicity, Missing Data and Analysis Populations

The registry record lists 3 outcome measures: the primary outcome titled Recruitment, Retention, Adherence and the secondary outcomes Aerobic Fitness and Glycemic Control. Assessing several outcomes can raise a multiplicity issue: when many hypotheses are tested, the chance of at least one apparently unusual result can increase. General approaches include prespecifying a primary outcome, adjusting for multiple tests, or treating secondary findings as exploratory. The registry record does not report a multiplicity strategy, and it reports 0 analyses. There are no posted test results to evaluate for multiplicity.

Missing-data handling is also not reported in the registry record. The primary outcome concerns trial completion, but no completion count or percentage is given. For the secondary outcomes, the record does not state how many observations were available, whether any measurements were missing, or how missing values were handled. Missingness can affect interpretation if participants with unavailable measurements differ from those whose outcomes are observed. That is a general concern, not a claim that missing observations occurred in this study.

The analysis population is not reported in the registry record. There is no description of which enrolled participants were included in any outcome analysis, or of how withdrawals, incomplete follow-up, or intervention participation were treated analytically. The record also does not report a statistical analysis plan. Without these details and numerical results, the degree to which the analyses followed a prespecified approach cannot be assessed.

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 0% reporting threshold.

The registry lists 11 participants at risk for serious adverse events and 0 affected. It also lists 11 at risk for other adverse events and 0 affected. These are the recorded counts for the Health Promotion Program group. The record does not list any serious adverse-event terms.

These entries describe what the registry reports; they do not establish that no adverse events occurred outside the reporting captured in the record, or that the intervention has no risk. The registry does not provide event definitions, severity details beyond the serious and other categories, timing, or a narrative safety assessment. The deaths field is null. A null entry is not the same as a reported zero, so deaths should not be described as zero on this basis.

Safety interpretation also depends on the scope and duration of monitoring, which are not reported in the registry record. The recorded at-risk counts indicate the group size for the event fields, not the completeness of event ascertainment. The figures should therefore be read narrowly as the event counts entered in the registry, rather than as a comprehensive estimate of safety.

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

The registry record establishes that a completed, single-group health promotion study enrolled 11 participants and planned a 10-week program. It describes supervised exercise, education, and dietary counseling, and names completion percentage as the primary outcome. Aerobic fitness and glycemic control are listed as secondary outcomes. These are descriptions of the study and its aims, not evidence of the outcomes achieved.

Numerical findings for completion, aerobic fitness, and glycemic control are not reported in the registry record. Consequently, the record does not show whether participants completed the program, whether they adhered to scheduled activities, or whether either secondary outcome changed. It also does not provide estimates of uncertainty or inferential tests. No conclusion about the magnitude, precision, or statistical evidence of an effect is supported by the posted results.

Even if outcome changes were available, the single-group design would limit causal interpretation. A change over time among participants would not, by itself, establish that the program caused the change. A separate comparator group is not recorded, so there is no direct comparison against participants following another approach or no program.

The study’s stated purpose was to gather preliminary feasibility data and evaluate outcome measures to inform future studies. That aim makes the design relevant as an exploratory effort, but it does not fill the reporting gaps. The registry record does not provide an observed effect estimate for use in planning, and the planning assumptions do not represent observed power. The most defensible reading is descriptive: the study structure and intended measures are documented, while the numerical outcome evidence needed to assess feasibility or effects is absent.

14. Why This Trial Matters Statistically

This study is statistically notable for the distinction between an outcome plan and an outcome result. The registry specifies a primary completion measure and names secondary health outcomes, but reports 0 analyses and no numerical outcome findings. Readers can identify what the investigators intended to evaluate, yet cannot assess the estimated completion percentage or any changes in aerobic fitness or glycemic control.

The design also shapes what future results could mean. A single-group study can provide descriptive information about participants who enroll and take part. It cannot make a direct randomized comparison with a control group when no comparator is recorded. That limitation is especially important when interpreting before-and-after change, since time trends and other influences can accompany participation.

Feasibility measures are useful because a program’s delivery and participant follow-through can affect whether a larger evaluation is practical. However, the registry’s outcome title and outcome description are not fully aligned in scope: the title names recruitment, retention, and adherence, while the description specifies the percentage of enrolled subjects who completed the trial. Separate definitions and results for those aspects are not reported. Clear operational definitions would help distinguish whether a challenge arose during recruitment, retention, or intervention attendance.

The record’s planning assumptions further illustrate why planning calculations and trial results must be kept separate. A planning illustration is not a finding from participants, and assumptions framed for a two-arm comparison do not automatically correspond to this single-group design. Without reported outcome estimates, neither the program’s observed effect nor the precision of a future sample-size estimate can be evaluated.

Thus, the statistical value of the record is primarily in documenting the study’s intended question, intervention, and design. Its missing numerical outcomes prevent assessment of what the study observed. This is a reporting boundary, not evidence of a particular favorable or unfavorable result.

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.

Several limitations specific to this study follow from the registry record. The enrolled group was small, with 11 participants, and the study is recorded as single-group. No comparator is listed, so a controlled estimate of differences between the program and another condition is unavailable. The record does not give participant characteristics, eligibility criteria, or recruitment details, limiting assessment of who the findings might represent.

The primary outcome’s title includes recruitment, retention, and adherence, but its description specifies the percentage of enrolled subjects who completed the trial. Definitions for recruitment and adherence as separate measures are not reported in the registry record. The record also does not provide the completion count or percentage. This limits interpretation of the feasibility question at the center of the stated primary outcome.

Numerical results for aerobic fitness and glycemic control are not reported, and the timing and methods of those assessments are not described. The registry reports 0 analyses, so there is no basis for assessing statistical methods, uncertainty, or the handling of repeated measurements. A statistical analysis plan, sample-size justification, interim analyses, missing-data approach, and analysis populations are not reported in the registry record.

Safety reporting is limited to the event counts entered in the record. Serious and other adverse events each list 11 at risk and 0 affected, while deaths are null. Event definitions, monitoring procedures, and further safety details are not reported. These limitations mean that the record can describe the planned program and study structure, but it cannot support a thorough assessment of outcomes, precision, generalizability, or safety.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Pilot Project of Health Promotion for People With Diabetes — NCT00970294.
• Registry record last updated 2012-08-21; status last verified 2012-07.
• Results first posted 2012-08-21.
• 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

NCT00970294, titled Pilot Project of Health Promotion for People With Diabetes, is recorded as COMPLETED. The official title describes a feasibility and effectiveness study of a health promotion program on aerobic fitness and glycemic control for adults with type 2 diabetes. The registry lists 11 enrolled participants, a single-group behavioral intervention, no masking, and allocation recorded as NA. The recorded start is 2007-07, and primary completion is 2008-05.

The program summary describes a 10-week intervention scheduled 3-4 days per week, including aerobic and strength training, nutrition counseling, and diabetes health education. The primary outcome concerns completion among enrolled subjects over 10 weeks. Aerobic fitness and glycemic control are secondary outcomes. The registry reports 0 analyses and does not report numerical outcome findings. Serious and other adverse-event entries each list 0 affected among 11 at risk; the deaths field is null.