Improving Medical Training for the Care of Chronic Conditions: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Improving Medical Training for the Care of Chronic Conditions (NCT00676208), a non-randomized na study. The primary outcome is Change in Confidence in Ability to Perform Teamwork.

2. Clinical Question

The educational context is chronic care. The registry’s description explains that a diabetes shared medical appointment can be a setting for both patient care and physician training, and frames the study around how trainees process that experience and learn about interdisciplinary approaches. The primary question therefore concerns a measure of trainees’ confidence, not a clinical outcome among patients with diabetes.

The study also lists change in professionals’ attitudes about diabetes as a secondary outcome. The registry record does not report results for that outcome. It does not establish whether any measured change was caused by participation, because students were not randomly allocated and the groups may have differed in ways that are not described.

3. Trial Design

The registry identifies this study as a completed, nonrandomized, parallel-group study, with no masking. Its title is Improving Medical Training for the Care of Chronic Conditions, and the listed condition is Diabetes Mellitus. The listed phase is NA. The sponsor is the VA Office of Research and Development. Registry dates are 2008-04 for study start and 2008-09 for primary completion; enrollment is recorded as 33.

One arm consisted of medical students who participated in shared medical appointments for patients with diabetes for one month. Students in the comparison arm did not participate in shared medical appointments. The record does not explain how students entered the arms, whether the groups were formed at the same time, or whether students could choose their participation. Those details matter because a nonrandomized comparison can reflect pre-existing differences between groups as well as any association with the educational experience.

No masking was reported. The registry does not describe blinding of students, outcome assessors, or analysts separately. It also does not report the study’s recruitment procedures, eligibility criteria, setting for student assessments, or whether all participants completed both assessments. These points cannot be filled in from the brief description of the appointment experience.

The primary outcome was change in confidence in ability to perform teamwork, measured before the intervention and after one month. A secondary outcome was change in professionals’ attitudes about diabetes. The registry record lists two outcome measures and two analyses, but does not provide their numerical results. It does not report a statistical analysis plan, a sample-size justification, or details of how the two groups were compared. The design and outcome descriptions can therefore be stated, but the magnitude and precision of any observed group difference cannot be assessed from the record.

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 Change in Confidence in Ability to Perform Teamwork, measured over Pre-intervention and Post-Intervention at 1 month.

The primary endpoint is change in confidence in ability to perform teamwork. It was assessed at pre-intervention and post-intervention at one month. The registry describes a three item scale covering confidence in conveying the logic of recommendations to other providers, explaining one’s distinctive perspective, and being accountable to patients for a decision made by a colleague from another discipline.

Responses for each item ranged from not at all confident (0) to very confident (4). The total scale ranged from 0 to 16, with higher values indicating more confidence. The registry says that post-pre difference scores were analyzed, so positive and higher difference scores indicate more favorable change. The endpoint is a measure of students’ reported confidence, not a direct measure of teamwork behavior, quality of care, or patient health.

Confidence is relevant to an educational intervention intended to expose trainees to interdisciplinary chronic care, because it addresses how prepared they feel to communicate and work across professional perspectives. However, interpretation depends on the actual changes, their uncertainty, and the way the groups were compared. The registry record does not report the mean changes, variability, between-arm estimate, or confidence interval. It is therefore not possible to judge the size or precision of the measured change from this record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The primary outcome is continuous: it is a total scale score, and the registry identifies the summary measure as a mean with standard deviation. A mean describes the average score or average change in a group. A standard deviation describes how dispersed individual scores are around that average. These summaries answer different questions: the mean describes the group’s central result, while the standard deviation describes variation among participants.

The registry says the outcome was analyzed as a difference score, calculated conceptually as the post-intervention score minus the pre-intervention score. A positive score represents more confidence after the intervention than before, under the stated scoring direction. A negative score would represent less confidence, and a score near zero would represent little change on the scale. Those statements explain how to interpret the measure; they do not describe the results of this study, because the registry record does not report the observed scores or changes.

For a comparison between arms, an analyst might compare average change scores or use a model that accounts for baseline and follow-up measurements. Those are general analytical possibilities, not a description of the specific between-arm method used. The record says difference scores were analyzed, but does not report the model or test used to compare arms, any covariate adjustment, or the assumptions checked. The statistical analysis plan is not reported in the registry record.

What does a confidence interval contribute?

In general, a confidence interval describes the range of estimates compatible with the data under a specified statistical method. It communicates precision: a narrower interval generally indicates more precise estimation, while a wider interval indicates greater uncertainty. A confidence interval also helps distinguish the estimated size of an effect from the question of whether a result crosses a conventional statistical threshold. No confidence interval for the primary outcome is reported in the registry record, so the precision of the estimate cannot be assessed.

Why does allocation matter?

In a randomized comparison, random assignment is intended to balance, on average, both measured and unmeasured characteristics between groups. Here allocation was nonrandomized. General sources of bias in this design include differences in prior confidence, clinical or educational experience, interest in chronic care, and circumstances that affect participation. The record does not say whether these characteristics differed, whether they were measured, or whether any adjustment was made. These possibilities are reasons for caution, not evidence of a particular bias in the observed data.

Nonrandom allocation also means that a simple difference between group averages would not, by itself, demonstrate that the appointment experience caused a difference. Even an adjusted estimate would depend on the measured covariates and the assumptions of the model. Since neither an estimate nor the analysis details are reported, the registry does not allow readers to assess the direction, size, or robustness of a group contrast.

How should scale scores be understood?

The three item scale combines responses about communication, explaining one’s perspective, and accountability across disciplines. Each item’s response range is stated as 0 to 4, while the total scale range is 0 to 16. The scale’s stated interpretation is that higher totals mean more confidence. This definition does not establish how reliably the scale measures confidence or whether the scale was validated for this particular group; those details are not reported in the registry record.

A change score can be useful because it expresses how an individual’s reported score differs between the two assessment times. It can also be affected by measurement variability, incomplete follow-up, and differences in baseline scores. The record does not report missing-score handling, the number with paired assessments, or baseline distributions. Therefore, readers cannot determine whether the reported analysis, if results were available elsewhere, included all enrolled students or only those with both measurements.

What can planning calculations show?

In general, a sample-size calculation estimates the number of participants needed under chosen assumptions about an effect, variability, significance level, allocation, and statistical method. A planning illustration based on an observed effect is not the same as the study’s original design justification and is not observed power. The registry does not report a sample-size justification or the numerical inputs and outputs needed to evaluate one. Its stated planning assumptions describe a two-sided significance level of 0.05, equal allocation, and a normal approximation, with the target effect expressed as a fraction of the observed effect. Those assumptions alone do not supply a result or establish that the study was adequately sized.

Overall, the outcome definition supports a clear interpretation of score direction, and general statistical principles explain what group means, variability, and intervals would contribute. But the registry’s missing outcome estimates and analysis details prevent a numerical assessment of the primary comparison.

10. Confidence Intervals for Each Arm

No two-arm comparison is shown for this trial, but each arm's mean can be given with a t-based 95% confidence interval computed from the posted mean, spread and number of participants.

R code and output

arm <- c("SMA Participants", "Comparison")
n   <- c(12, 13)
m   <- c(1.4, -0.12)
sp  <- c(0.65, 0.6)
sd  <- sp      # posted standard deviations
for (i in seq_along(n)) {
  se <- sd[i] / sqrt(n[i]); h <- qt(0.975, n[i] - 1) * se
  cat(sprintf("CARM|%s|%d|%.3f|%.3f|%.3f|%.3f\n", arm[i], n[i], m[i], sd[i], m[i] - h, m[i] + h))
}

CARM  SMA Participants  12  1.400  0.650  0.987  1.813
CARM  Comparison  13  -0.120  0.600  -0.483  0.243

11. Multiplicity, Missing Data and Analysis Populations

The registry lists two outcome measures and two analyses. It identifies change in confidence in ability to perform teamwork as the primary outcome and change in professionals’ attitudes about diabetes as a secondary outcome. It does not report whether the analyses were prespecified in a protocol, whether either outcome was prioritized beyond this labeling, or whether any adjustment was made for examining multiple outcomes. A multiplicity adjustment is not reported in the registry record.

Multiplicity matters in general because examining several outcomes or analyses can increase the chance of a statistically notable result arising by chance. Whether adjustment is appropriate depends on the study questions and analysis plan. Since the plan and numerical results are not reported, it is not possible to determine how multiplicity was handled or to interpret statistical significance across outcomes.

The registry record does not describe missing data, withdrawals, incomplete questionnaires, or the number of students contributing paired pre- and post-intervention scores. It does not state whether missing observations were excluded, imputed, or handled with a model. The record also does not report an analysis population definition, such as whether analyses included all enrolled students or a subset with available outcome data.

These omissions affect interpretation because a mean change based only on participants with complete assessments can differ from the change that would have been observed if all enrolled students had completed follow-up. That is a general concern; the registry record does not establish that missing data occurred or that any particular method was used. Interim analyses and stopping rules are not reported in the registry record. Without these details and the outcome estimates themselves, readers cannot evaluate the analysis population, missing-data assumptions, or the handling of multiple comparisons.

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’s adverse-event entries report zero serious adverse events among the listed at-risk groups: SMA Participants, with 14 at risk, and Comparison, with 19 at risk. The entries for other adverse events also report zero in groups with the same stated risk counts. The death fields are null, so deaths are not reported in the registry record.

These figures should be read as registry entries, not as proof that no adverse events occurred in every sense. A recorded zero means that zero events are entered for the listed outcome and group; it does not establish how events were defined, monitored, collected, or adjudicated. Those methods are not reported in the registry record. In particular, the record does not provide descriptions of surveillance procedures or a discussion of whether an event could have gone unrecorded.

The reported risk counts belong to the safety entries and should not be treated as the number with completed primary-outcome assessments. The record also does not provide a safety comparison or enough detail to infer differences in risk between groups. These are descriptive safety figures, separate from the educational confidence outcome, and they do not answer whether the intervention changed students’ reported confidence.

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

This study addresses a practical question in medical education: whether participation in shared medical appointments for patients with diabetes is associated with a change in students’ confidence about teamwork. The registry describes an outcome that captures communication and accountability across professional disciplines and specifies how to interpret its direction. That makes the intended educational construct clear.

The record does not, however, report the primary outcome results. It does not give the observed mean change for either arm or the estimate and uncertainty for a comparison between them. As a result, it cannot show whether students who participated reported more favorable change, less favorable change, or a change similar to the comparison group. The secondary attitude outcome is also listed without results.

Even with outcome results, the nonrandomized design would require cautious interpretation. Group membership may be associated with characteristics that also relate to confidence, and the registry does not describe whether those characteristics were measured or accounted for. A group difference would therefore not automatically be attributable to the appointments. This is a design limitation, not a finding that the groups were in fact different.

The measured outcome is self-reported confidence over the stated pre-intervention and one-month post-intervention period. It is not direct evidence of improved teamwork in practice, better care for patients, or lasting educational change. The registry record does not report objective performance measures or longer-term assessment.

The appropriate conclusion is limited: the record describes a completed, nonrandomized educational study and defines a relevant confidence scale, but does not report outcome estimates. It therefore does not support a conclusion about the direction, magnitude, precision, or cause of any change. Absence of reported results should not be mistaken for evidence of no change, just as the description of an intended educational benefit should not be mistaken for evidence that one occurred.

14. Why This Trial Matters Statistically

The study is statistically interesting because it makes a distinction between an educational experience and the outcome used to evaluate it. Participation in shared medical appointments is the intervention, while confidence in teamwork is a reported scale outcome. Keeping those concepts separate helps prevent a measure of perceived confidence from being interpreted as direct evidence of clinical performance or patient benefit.

The registry also illustrates why design labels matter. A nonrandomized, parallel-group comparison can be informative about how outcomes vary with participation, but it does not provide the same protection against confounding as random assignment. The registry itself cautions that the arms are not a like-for-like control comparison. Readers should therefore distinguish the question the study set out to examine from a causal claim that its design may not establish.

Outcome reporting is equally important. The record explains the scale, its direction, and the timing of assessment, yet does not report the numerical results. Without estimates and measures of uncertainty, a reader cannot evaluate how large a change was, how variable scores were, or how compatible the data are with a range of possible group differences. The outcome definition alone is not enough to assess the evidence.

Finally, the stated sample-size assumptions are planning concepts, not results. General planning calculations depend on assumptions about the effect and statistical method, and calculations based on observed effects should not be confused with observed power. The registry does not report a sample-size justification or outcome estimates from which the study’s precision could be judged. These features make the record a useful example of why complete outcome reporting and careful limits on interpretation matter in educational research.

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 most important limitation for interpreting the registry record is that it does not report numerical results for the primary or secondary outcomes. There is no mean change, standard deviation, between-arm estimate, confidence interval, or p-value for the primary endpoint. This prevents assessment of the outcome’s direction, magnitude, and precision.

The allocation was nonrandomized, and the registry cautions that the groups are not a like-for-like comparison. The record does not explain how students were assigned to participation status, whether they differed at baseline, or whether analyses adjusted for any differences. Any observed contrast would therefore need to be interpreted cautiously, and the available record does not permit that contrast to be examined.

The outcome is confidence reported on a scale. The registry describes the scale items and scoring direction but does not report information about its reliability, validity, or sensitivity to change in this study. Nor does it report whether outcome assessors were masked; no masking was reported for the study. These omissions limit conclusions about measurement and potential influence on self-reported responses.

The record does not describe missing data, completion of both assessments, analysis-population criteria, or the handling of incomplete questionnaires. It also does not provide detailed analysis methods, covariate adjustments, a statistical plan, a sample-size justification, or methods for managing multiple outcomes. Further, the primary measure is assessed at one month; longer-term outcomes are not reported in the registry record. These are limits of the information recorded, not proof that particular procedures were absent from the conduct of the study.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Improving Medical Training for the Care of Chronic Conditions — NCT00676208.
• Registry record last updated 2021-09-23; status last verified 2021-08.
• Results first posted 2014-12-04.
• 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

NCT00676208, Improving Medical Training for the Care of Chronic Conditions, is listed as completed and sponsored by the VA Office of Research and Development. The registry records a nonrandomized, unmasked, parallel-group study, with enrollment of 33 and dates from 2008-04 to 2008-09.

Medical students in one arm participated in shared medical appointments for patients with diabetes for one month; students in the comparison arm did not. The primary outcome was change in confidence in ability to perform teamwork, assessed before and after the intervention at one month. The secondary outcome was change in professionals’ attitudes about diabetes.

The registry describes the primary scale and its scoring direction but does not report numerical results for either outcome. It also does not report the statistical analysis plan, missing-data handling, or analysis-population definition. Serious and other adverse-event entries are recorded as zero for the listed risk groups; deaths are not reported in the registry record.