This page provides an independent statistical analysis and educational interpretation of publicly reported results. ClinicalTrials.gov provides the official trial registry record. Numerical trial results on this page are restricted to the results posted in the ClinicalTrials.gov record; calculations added by Clinical Biostats are labelled as such.
1. Trial at a Glance
This page covers the registry results for Treatment of Diabetes and Depression in Hispanics and African Americans and Its Effect on A1c and Quality of Life. (NCT00624013), a randomized phase 4 study. The primary outcome is HbA1C (%).
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT00624013 |
| Phase | Phase 4 |
| Condition | Diabetes, Depression |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | Triple |
| Enrollment | 89 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Charles Drew University of Medicine and Science |
| Results posted | Yes |
2. Clinical Question
Population
Underserved Hispanic and African American participants with diabetes and depression. The registry record lists an enrollment of 89. Further eligibility details and the characteristics of participants who entered the outcome analyses are not reported in the registry record.
Intervention
Sertraline, described as 50 mg up to 100 mg daily for 6 months. The registry names Zoloft in the sertraline arm description.
Comparator
Placebo, described as 50 mg up to 100 mg daily for 6 months. The trial is identified as randomized and placebo controlled.
Primary question
Whether pharmacological treatment of depression with sertraline is associated with change in HbA1C from month 0 to month 6, compared with placebo, in the stated population. The primary outcome is identified, but the registry record does not report a treatment-effect estimate or its uncertainty.
The registry describes the intended question as whether treating depression would improve HbA1C and quality of life during intervention and six months after intervention. HbA1C is the registered primary outcome; quality of life is listed as a secondary outcome. The posted outcome description focuses on change in HbA1C at month 0 and month 6. It does not report a numerical comparison of change between the randomized groups, nor does it provide group-specific means or standard deviations for the primary outcome.
Accordingly, the clinical question can be stated from the trial design, but the posted record does not supply the outcome evidence needed to answer it. The registry record is marked completed, yet completion status alone does not establish what the trial found. The available record also does not establish whether the intended quality-of-life assessment or the follow-up six months after intervention was reported as an outcome result.
3. Trial Design
This was a Phase 4, randomized, triple-masked, parallel-group trial sponsored by Charles Drew University of Medicine and Science. The registry lists diabetes and depression as the conditions, and sertraline and placebo as the interventions. The arm descriptions specify daily dosing of 50 mg up to 100 mg for 6 months in each group. Enrollment is listed as 89, and the registry status is completed.
In general, randomization assigns participants to treatment groups by chance, which is intended to reduce systematic differences between groups at the start of a trial. A placebo comparator can help distinguish changes associated with assignment to the study drug from changes also seen under the comparison condition. These design features do not guarantee that the groups were alike in every respect, and they do not by themselves establish the outcome of the comparison.
Triple masking indicates that masking was recorded at that level, but the registry record does not identify the particular roles whose knowledge of assignment was masked. It also does not describe how masking was maintained or whether it was assessed. A parallel design means the record identifies separate treatment groups rather than a crossover comparison; details about treatment switching or adherence are not reported in the registry record.
The listed study start is 2006-09 and primary completion is 2008-10. The brief summary describes an intended assessment during intervention and six months after intervention. The primary outcome entry specifies HbA1C, measured as percentage of glycosylated hemoglobin, with a timeframe of month 0 and month 6. Quality of life is listed as a secondary outcome. Further protocol details, including eligibility criteria, recruitment procedures, and the actual timing of any follow-up beyond the stated outcome timeframe, are not reported in the registry record.
Although the trial is marked completed, the posted results do not include an analyzable primary-outcome treatment comparison. The registry indicates two outcome measures and zero analyses. These record-level details describe what is listed; they do not establish whether analyses were conducted outside the registry or whether other results are available elsewhere.
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
| Stage | Placebo Comparator:Placebo | Active Comparator: Sertraline |
|---|---|---|
| STARTED | 44 | 45 |
| COMPLETED | 36 | 39 |
| NOT COMPLETED | 8 | 6 |
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.
| Characteristic | Unit | Placebo Comparator: Placebo | Active Comparator: Sertraline | Total |
|---|---|---|---|---|
| Participants analysed | 44 | 45 | 89 | |
| Age, Continuous | years | 53 (SD 10) | 52 (SD 8) | 53 (SD 8) |
| Sex: Female, Male: Female | Participants | 32 | 33 | 65 |
| Sex: Female, Male: Male | Participants | 12 | 12 | 24 |
| Race/Ethnicity, Customized: Hispanic | participants | 39 | 39 | 78 |
| Race/Ethnicity, Customized: African American | participants | 5 | 5 | 10 |
| Region of Enrollment: United States | participants | 44 | 45 | 89 |
6. Primary Endpoint
The registry lists the primary outcome as HbA1C (%), measured over Month 0 and month 6.
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | Standard Deviation |
| Unit | Percentage of glycosylated hemoglobin |
| Endpoint classification | Continuous Endpoint |
The primary endpoint is HbA1C, reported in the registry as a continuous measure expressed as a percentage of glycosylated hemoglobin. The registered outcome description is change in HbA1C at month 0 and month 6. The planned comparison is relevant to the trial’s stated question because it concerns whether the intervention is associated with a different change in this measure than the placebo condition.
The registry identifies the parameter as a mean and the dispersion measure as a standard deviation. A mean describes the group’s average value; a standard deviation describes how spread out individual values are around that average. Both can help characterize an outcome, but neither alone gives the treatment effect. For a randomized comparison, an estimate of the difference in change between groups, accompanied by a measure of uncertainty, would be needed to assess the size and precision of the contrast.
HbA1C was selected as the primary outcome for a trial involving participants with diabetes, while quality of life is listed as secondary. The record’s summary states the hypothesis that treating depression would improve HbA1C and quality of life. That stated rationale is not a result. The registry does not report the group means, standard deviations, or a numerical between-group change estimate for HbA1C. It therefore does not permit assessment of the direction, magnitude, or precision of the primary-outcome comparison.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record identifies a clear primary measure and a comparison between sertraline and placebo, but it does not report the numerical primary-outcome results needed to interpret that comparison. There are no posted HbA1C group means, standard deviations, treatment-effect estimate, confidence interval, or p-value in the record described. As a result, the registry does not establish whether the groups changed differently, how large any difference was, or how precisely it was estimated.
The outcome entry specifies month 0 and month 6 and describes change in HbA1C. However, the record’s note about the outcome says that it has several categories or time points and was not reduced to one comparison. This matters because a result for one time point or one selected contrast would not necessarily represent the full registered outcome. Without the detailed outcome values and a clearly identified comparison, readers cannot determine which component was analyzed or how results across the stated time points were handled.
In general, a confidence interval describes a range of values compatible with the data and the analysis assumptions; it communicates uncertainty around an estimate. A p-value summarizes how compatible the observed data are with a specified null model, under the assumptions of the statistical test. Neither measure conveys the clinical importance of a difference by itself. For this trial, neither a confidence interval nor a p-value for the primary comparison is reported in the registry record, so those aspects of the evidence cannot be evaluated.
Enrollment is listed as 89, but that figure does not show how many participants contributed data to the primary outcome, how many were assigned to each arm for this endpoint, or whether missing measurements affected the analysis. The registry does not report an analysis population, participant flow, missing-data handling, or reasons for unavailable outcome measurements. Those omissions prevent assessment of how representative the posted outcome data would be, even if a summary estimate were available.
The record lists quality of life as a secondary outcome, but does not give its result. It also identifies the study’s intended interest in assessments during treatment and after intervention; the actual findings for those periods are not reported in the registry record. Thus, neither the primary nor secondary efficacy question can be resolved from the posted results. Completion status should not be mistaken for a reported positive or negative finding.
The registry does include adverse-event figures, but these do not substitute for the missing HbA1C and quality-of-life results. Safety counts and efficacy outcomes address different questions. Nor can the adverse-event entries be used to infer whether sertraline changed HbA1C. The appropriate interpretation is limited: the record describes a randomized trial and names its intended endpoint, while leaving the primary treatment-effect estimate and its uncertainty unavailable.
9. Statistical Methods Explained
The design and outcome fields permit a limited explanation of how a trial of this type can be interpreted, but the registry does not report a detailed statistical analysis plan. General statistical concepts below clarify what information would ordinarily be needed; they do not imply that the trial used any particular model or procedure.
What does randomization contribute?
Randomization assigns participants to groups by chance. In general, this helps prevent treatment assignment from being deliberately or systematically determined by participant characteristics. If allocation is implemented as planned and outcome data are sufficiently complete, comparing randomized groups can support an estimate of the effect of assignment to the intervention relative to the comparator. Randomization does not make every group characteristic identical, and it does not resolve problems caused by missing outcome data, deviations from assigned treatment, or an unclear analysis population.
The registry records the allocation as randomized and the model as parallel. It does not report the random-sequence method, allocation concealment, stratification factors, or any procedures used to address imbalances. Those details are not reported in the registry record. The entry also identifies triple masking, but does not say which study roles were masked or how masking was maintained.
What would a change comparison mean?
The primary outcome is described as change in HbA1C between month 0 and month 6. A change score represents how a participant’s measure differs between the specified assessments. Comparing average change between randomized groups can describe whether the groups had different average trajectories over that interval. An alternative approach can model follow-up values while accounting for baseline values. Both approaches can be reasonable in suitable circumstances, but they answer the question through different statistical formulations and can yield estimates with different precision.
The registry record does not identify which formulation was used. It also does not report whether the analysis adjusted for baseline HbA1C or other covariates, how repeated measurements were modeled, or how the outcome’s several categories or time points were selected for analysis. No particular method should therefore be attributed to the trial based on the endpoint description alone.
Why report spread and uncertainty?
The outcome is identified as a mean with standard deviation. The mean locates the average outcome, while the standard deviation describes variation among observations. A standard deviation is not the same as the standard error: the standard error describes uncertainty in an estimated mean and depends on the amount of information used. To interpret a comparison, readers generally need an effect estimate and an uncertainty measure such as a confidence interval. The registry record does not report those primary-outcome quantities.
In general, a confidence interval should be interpreted alongside the estimate and the analysis assumptions. A narrow interval indicates greater precision than a wide interval, but precision alone does not determine importance. An interval spanning values on both sides of no difference may be compatible with a range of effects; it should not be reduced to a simple claim that there was no effect. No such interval is reported for the primary outcome in this record.
What is over-dispersion, and is it relevant?
Over-dispersion occurs when observed variation in a statistical outcome is greater than a model assumes. If a model underestimates variation, standard errors can be too small and uncertainty can appear less than it is. This concept is most relevant to outcomes whose distributions are modeled using specific assumptions, such as counts or binary responses. The registered primary outcome is continuous, and the record identifies a mean and standard deviation; no model details are given that would establish an over-dispersion issue. It would be inappropriate to claim that over-dispersion affected this analysis.
What do the planning illustrations represent?
The record describes sample-size planning illustrations based on a fraction of an observed effect, with a two-sided significance level of 0.05, equal allocation, and a normal approximation. It distinguishes participants per arm for ordinary outcomes from total events for time-to-event outcomes. These are planning illustrations, not the trial’s original design justification and not observed power. The registry does not report the trial’s own sample-size justification or the assumptions used when it was designed. No numerical planning results are included in the record, so no particular planning requirement can be interpreted.
In general, a planning calculation estimates the information needed to detect a prespecified effect under its assumptions. It is not a measure of the probability that a completed trial’s finding is true, and it cannot replace the observed effect estimate and its confidence interval. When a planning illustration uses an observed effect, its output depends on that estimated effect and can be unstable if the estimate is imprecise. The listed assumptions should therefore be read as illustrative rather than as evidence about the trial’s achieved precision.
What statistical plan is documented?
The registry lists zero analyses and does not report the test, model, covariate adjustment, treatment of repeated measurements, or analysis population for the primary outcome. Interim analyses and stopping rules are not reported in the registry record. It is also not stated how multiplicity was handled across outcome measures, categories, or time points. These omissions mean that readers cannot reproduce or fully evaluate an analysis from the registry entry alone. General methodological possibilities should not be mistaken for methods documented for this trial.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists HbA1C as the primary outcome and quality of life as a secondary outcome. It also describes the primary outcome as involving several categories or time points, and the outcome was not reduced to one comparison. When a study examines multiple outcomes, time points, or contrasts, the chance of finding an apparently notable result by chance can increase if each is tested separately. In general, prespecifying a primary comparison and choosing an appropriate multiplicity strategy can help readers interpret a family of results. The registry record does not report a multiplicity adjustment or a detailed plan for selecting and interpreting comparisons.
Missing-data handling is not reported in the registry record. There is no description of the amount or pattern of missing HbA1C or quality-of-life data, reasons for missing measurements, or methods used to address them. Missingness can affect both the precision and the validity of an estimate, especially if availability of an outcome is related to treatment assignment or participant characteristics. Without these details, the impact of missing data cannot be assessed.
The analysis population is also not reported. The registry does not specify whether the primary analysis included participants according to randomized assignment, treatment received, or another definition. It does not report participant flow from enrollment through outcome assessment or the number contributing to each analysis. The enrollment figure of 89 cannot be treated as the analysis denominator.
The registry record does not report interim analyses or stopping rules. It also does not state whether a statistical analysis plan was finalized before outcome data were examined. These details matter when assessing how flexible the analysis may have been, but their absence does not establish that any particular practice occurred. The record’s zero listed analyses should be read as a limitation of the posted registry information, not as proof that no analysis was conducted.
11. Safety Results
The registry reports serious adverse events as affected participants divided by participants at risk.
| Arm | Participants with serious adverse events | Participants at risk | Percentage |
|---|---|---|---|
| Placebo | 2 | 44 | 4.5% |
| Sertraline | 0 | 45 | 0.0% |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 0% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Placebo | 1 of 44 |
| Sertraline | 3 of 45 |
Most frequent serious adverse event terms
| Event term | Organ system | Placebo | Sertraline |
|---|---|---|---|
| Suicidal ideation | Psychiatric disorders | 1 of 44 | 0 of 45 |
| skin rash | Skin and subcutaneous tissue disorders | 1 of 44 | 0 of 45 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Placebo | Sertraline |
|---|---|---|---|
| moved out of the country | Social circumstances | 1 of 44 | 3 of 45 |
Serious events with the highest arm-level rate: suicidal ideation (2.3%), skin rash (2.3%).
The registry lists serious adverse-event figures separately from other adverse-event figures. For placebo, it reports 2 participants affected among 44 at risk for serious adverse events, and 1 among 44 at risk for other adverse events. For sertraline, it reports 0 participants affected among 45 at risk for serious adverse events, and 3 among 45 at risk for other adverse events. These are the counts recorded in the registry; they should not be treated as a comprehensive description of every safety outcome.
The record also names suicidal ideation and skin rash as top serious terms, with 2.3% listed for each. The record does not provide the event-level details needed to connect those terms to particular participants or to interpret their timing, severity, or relationship to study treatment. Death figures are not reported in the registry record.
These entries describe reported events, not comparative risk estimates. The counts do not establish that a treatment caused an event, and they do not establish that an event could not occur when no affected participants are listed. The registry record does not provide confidence intervals, a formal safety comparison, or additional detail about ascertainment and follow-up. Interpretation should therefore remain descriptive and limited to the recorded figures.
12. What the Result Does, and Does Not, Mean
The registry supports a description of the trial’s question and design: a randomized, placebo-controlled comparison of sertraline and placebo in underserved Hispanic and African American participants with diabetes and depression, with change in HbA1C identified as the primary outcome. It also documents a quality-of-life secondary outcome and adverse-event entries. Those details describe what was registered; they do not demonstrate what happened to the primary endpoint.
The registry record does not report the primary-outcome means, standard deviations, treatment-effect estimate, confidence interval, or p-value. It therefore cannot show whether the groups differed in HbA1C change, the direction of any difference, its magnitude, or how precisely it was estimated. The absence of a posted estimate is not evidence that the groups were the same, and it is not evidence that the intervention had a beneficial or harmful effect.
Likewise, the quality-of-life outcome is named but its result is not reported. The study summary describes an intended assessment during intervention and six months after intervention, but the registry does not provide findings for the post-intervention period. The completed status does not fill these gaps. It indicates the registry’s status field, not the availability or direction of results.
In general, a statistically distinguishable result and a clinically important result are not interchangeable. A treatment-effect estimate and its uncertainty are needed to assess how compatible the data are with different effect sizes; contextual criteria are needed to judge what magnitude might matter to participants and clinicians. Neither can be applied to the primary outcome from the posted registry information because the necessary outcome estimate is absent.
The adverse-event counts should also be kept separate from efficacy interpretation. They give a limited account of recorded safety events and do not answer the HbA1C or quality-of-life question. Overall, the record establishes the intended comparison and some design and safety details, but it does not supply the outcome evidence needed to draw a conclusion about the trial’s primary clinical question.
13. Why This Trial Matters Statistically
This trial is statistically notable as an example of why a registered design and a reported result are different forms of evidence. The record identifies the population, randomized comparison, primary endpoint, and measurement timeframe. Those details make the intended question understandable. Yet without a reported treatment-effect estimate and its uncertainty, the central statistical comparison cannot be evaluated.
The endpoint description also illustrates the importance of clarity when an outcome includes multiple categories or time points. The registry notes that the primary outcome was not reduced to one comparison. Without detailed results and an analysis description, readers cannot know which contrast would represent the primary question or how the components relate to one another. Reporting a clearly defined estimate alongside its uncertainty is essential for transparent interpretation.
The record further shows why enrollment is not a substitute for an analysis population. The enrollment figure does not disclose how many participants contributed outcome measurements, how missing observations were handled, or whether all randomized participants were included according to assignment. Those details affect the interpretation of precision and potential bias.
Finally, the distinction between a sample-size planning illustration and observed evidence is important. Planning assumptions do not tell readers what effect the trial estimated or how precise that estimate was. The registry describes illustrative calculations based on an observed effect, but the actual primary outcome analysis is not reported. These limitations are not specific to any one statistical technique: clear outcome definitions, transparent analysis populations, missing-data methods, multiplicity handling, and effect estimates with uncertainty are all needed for a complete account of trial evidence.
14. 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 main limitation is that the registry does not report an analyzable comparison for the primary HbA1C outcome. Group means, standard deviations, an estimate of between-group change, and measures of uncertainty are not reported in the registry record. As a result, the primary question cannot be answered from the posted results.
The primary outcome is described as involving several categories or time points and was not reduced to one comparison. The record does not explain how those components were defined or analyzed. Although month 0 and month 6 are specified as the timeframe, there is no detailed outcome dataset or statistical method to clarify the intended contrast.
The registry also does not report the quality-of-life result, even though quality of life is listed as a secondary outcome. Findings for the post-intervention period described in the study summary are not reported in the registry record. The amount and pattern of missing data, analysis population, participant flow, and reasons for unavailable measurements are also not reported.
Further limitations are the absence of a detailed statistical analysis plan, multiplicity approach, model specification, and information about interim analyses or stopping rules. The identity of the roles masked in this triple-masked trial and the procedures used to maintain masking are not reported. The record does not state how adherence, treatment discontinuation, or deviations from assigned treatment were handled.
Safety information is limited to the recorded adverse-event counts and listed serious terms. The registry does not provide additional event-level context, a formal comparative safety analysis, or death figures. These gaps constrain interpretation of safety as well as efficacy. They should be understood as limitations of what is reported in the registry record, not as proof that the unreported procedures or results do not exist elsewhere.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Treatment of Diabetes and Depression in Hispanics and African Americans and Its Effect on A1c and Quality of Life. — NCT00624013.
- Registry record last updated 2017-12-12; status last verified 2017-11.
- Results first posted 2017-12-12.
- 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.
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18. Record Summary
The registry describes a completed, Phase 4, randomized, triple-masked, parallel-group trial sponsored by Charles Drew University of Medicine and Science. It compares sertraline with placebo in underserved Hispanic and African American participants with diabetes and depression. Enrollment is listed as 89; each arm description specifies a daily dose of 50 mg up to 100 mg for 6 months.
HbA1C, expressed as percentage of glycosylated hemoglobin, is the primary outcome, with change assessed at month 0 and month 6. Quality of life is listed as a secondary outcome. The record does not report a primary-outcome treatment-effect estimate or the quality-of-life result. It notes multiple categories or time points for the primary outcome and does not reduce these to one comparison.
Adverse-event counts and serious-event terms are recorded, but the registry does not provide a full safety analysis. Analysis populations, missing-data methods, multiplicity handling, and a detailed statistical plan are not reported in the registry record. The available information therefore describes the trial’s design and intended outcomes more fully than its statistical findings.