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 Yo Puedo! Diabetes Self-Management Education + mHealth in Mexico City (NCT03159299), a randomized na study. The primary outcome is Change in Hemoglobin A1C From Baseline.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT03159299 |
| Phase | NA |
| Condition | Type 2 Diabetes Mellitus |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | None (open label) |
| Enrollment | 47 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Yale University |
| Results posted | Yes |
2. Clinical Question
Population
Adults with type 2 diabetes in Mexico City receiving care through Seguro Popular clinics were the intended study population. The registry describes adaptation of the program with input from diabetes experts, clinic administrators, health professionals, and adults with diabetes. The total enrollment recorded is 47.
Intervention
The intervention was a modified Yo Puedo diabetes self-management education program combined with mHealth. The mHealth component used pictorial text messages. The registry describes collaborative adaptation to local cultural norms, provider expertise, and clinic systems.
Comparator
The comparator was a wait-list control condition. Participants in this group were not to receive Yo Puedo with mHealth during the 6 month data collection period and were to be invited to participate after data collection finished.
Primary question
The primary outcome concerned change in hemoglobin A1C from baseline to 6 months. The registry’s study description also identifies clinical measures, diabetes self-management, and self-efficacy as outcomes of interest at 3 and 6 month follow-up. Numerical results for the primary comparison are not reported in the registry record.
This was described as a randomized, controlled pilot study. Its aims combined evaluation of implementation and acceptability with preliminary efficacy. Feasibility included implementation processes, fidelity of sessions, attendance, and attrition; acceptability was to be assessed through interviews with nurses, community health workers, and participants. The registry’s stated hypothesis was that the intervention group would have greater clinical and self-management outcomes than the wait-list group at follow-up. That statement is a hypothesis, not evidence that an outcome difference was observed. Because the numerical primary results are not reported in the registry record, the direction, size, and precision of the primary comparison cannot be assessed from the record.
3. Trial Design
The registry identifies this as a randomized, parallel-group study with no masking. The intervention was behavioral, and the listed phase is NA. The study is marked completed. Its recorded enrollment is 47. The brief study description refers to randomizing 40 adults, so the record contains both that planned figure in the description and an enrollment figure of 47; the reason for the difference is not reported in the registry record. The start date is 2017-05-08 and the primary completion date is 2019-04-28.
The active group was assigned to the modified Yo Puedo plus mHealth program. The wait-list group did not receive that program during the 6 month data collection period and was to be invited to participate once data collection ended. The study was conducted in Mexico City, with the program intended for adults with type 2 diabetes in Seguro Popular clinics. The sponsor is Yale University.
The registry describes the project as both an adaptation effort and a pilot evaluation. Adaptation was intended to reflect local cultural norms, providers’ expertise, and clinic systems of care. The study description names feasibility, acceptability, fidelity, and preliminary efficacy as evaluation aims. This context matters: a pilot can assess whether a program and its evaluation procedures are workable, while also collecting preliminary outcome information. It does not follow that the study was designed to establish a definitive treatment effect.
The registry does not report the method used to generate or conceal the randomization sequence, the allocation ratio, or whether any stratification or blocking was used. It records no masking. The exact visit schedule and the timing of each outcome measurement beyond the primary outcome’s stated baseline, 3, and 6 month timeframe are not further detailed. Detailed eligibility criteria, clinic counts, and the number of participants assigned to each study arm are not reported in the registry record. These omissions limit how fully the conduct and representativeness of the study can be evaluated.
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 | Yo Puedo | Wait-list Control |
|---|---|---|
| STARTED | 26 | 21 |
| COMPLETED | 24 | 20 |
| NOT COMPLETED | 2 | 1 |
Analysis population for the primary outcome, as defined in the registry: Intention to treat analysis included all observations for all relevant time points used in the calculation.
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 | Yo Puedo | Wait-list Control | Total |
|---|---|---|---|---|
| Participants analysed | 26 | 21 | 47 | |
| Age, Continuous | years | 53.9 (SD 9.2) | 56.8 (SD 8.3) | 55.4 (SD 8.8) |
| Sex: Female, Male: Female | Participants | 17 | 14 | 31 |
| Sex: Female, Male: Male | Participants | 9 | 7 | 16 |
| Ethnicity (NIH/OMB): Hispanic or Latino | Participants | 26 | 21 | 47 |
| Ethnicity (NIH/OMB): Not Hispanic or Latino | Participants | 0 | 0 | 0 |
| Ethnicity (NIH/OMB): Unknown or Not Reported | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Asian | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Black or African American | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): White | Participants | 26 | 21 | 47 |
| Race (NIH/OMB): More than one race | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 0 | 0 | 0 |
| Region of Enrollment: Mexico | participants | 26 | 21 | 47 |
| Marital Status | Participants | 15 | 13 | 28 |
6. Primary Endpoint
The registry lists the primary outcome as Change in Hemoglobin A1C From Baseline, measured over Baseline, 3, 6 months.
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | Standard Deviation |
| Unit | percentage HbA1c |
| Endpoint classification | Continuous Endpoint |
The primary endpoint is change in hemoglobin A1C from baseline, expressed in percentage HbA1c. The registry identifies the primary timeframe as baseline, 3, and 6 months, and its description specifically defines the reported change as baseline to 6 months. HbA1c was measured using a finger stick blood sample. The outcome is continuous, and the registry identifies the summary parameter as a mean with standard deviation.
As general statistical context, HbA1c is used in diabetes research as a measure of longer-term blood glucose exposure. A change-from-baseline endpoint describes how a measurement shifts over follow-up relative to a participant’s starting value. Comparing such changes between randomized groups can help assess whether the groups followed different average outcome patterns during the study period. Interpretation depends on the estimated difference, its uncertainty, the analysis population, and the way repeated measurements and missing observations were handled.
The registry says that a generalized linear mixed model was used for the primary analysis and that the analysis followed an intention-to-treat approach. It does not report the estimated mean change in either group, the between-group contrast, a confidence interval, or a p-value. Therefore, the magnitude and precision of the primary outcome comparison are not reported in the registry record. No conclusion about the observed direction or size of the primary result can be drawn from the endpoint description alone.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record identifies a clinically relevant outcome and an analysis approach, but it does not report the numerical primary outcome result. It names change in HbA1c from baseline to 6 months as the primary endpoint and says that a generalized linear mixed model was used in an intention-to-treat analysis. Without the group estimates or a between-group contrast, the posted record does not establish whether the observed mean change favored either group, how large any difference was, or how uncertain the estimate might be.
A complete interpretation of a continuous endpoint generally needs the estimated outcome in each group or, preferably for a randomized comparison, an effect estimate for the difference between groups. A confidence interval would describe the range of effect sizes reasonably compatible with the analysis and data under the model assumptions. A p-value, if reported, would describe the compatibility of the data with a specified null hypothesis under those assumptions. These are general statistical explanations; the corresponding estimates and inferential statistics are not reported in the registry record.
The record describes the study as a pilot and includes feasibility and acceptability aims alongside preliminary efficacy. Pilot findings can be informative about the practical delivery of a program and about the procedures needed for a later evaluation. They should not be treated as definitive evidence of an outcome effect without considering the size and precision of the estimate, study conduct, and the limits of the design. The registry does not report numerical feasibility or acceptability findings, such as attendance, attrition, fidelity, or interview results. Those outcomes therefore cannot be evaluated from the registry record either.
The recorded enrollment is 47, while the brief description says that 40 adults would be randomized. The record does not explain this distinction. The safety figures list 26 participants at risk in the Yo Puedo group and 21 in the wait-list control group, but those safety counts do not by themselves establish the analysis denominator for the primary endpoint or clarify how many participants contributed measurements at each time point.
There is also no reported primary estimate at 3 months in the primary outcome result details, even though the outcome timeframe lists baseline, 3, and 6 months. The primary description identifies baseline-to-6-month change as the result of the model. The number of measurement occasions used in the fitted model, the contrast extracted from it, and its uncertainty are not reported in the registry record. Consequently, the record supports a description of the planned question and named method, but not a quantitative judgment about the primary outcome.
Any reading should separate the study hypothesis from observed results. The registry’s stated expectation that outcomes would be greater in the intervention group is not a result. Since no numerical primary result is reported, neither a clinically important difference nor a negligible difference can be inferred. The absence of an estimate is not evidence that the groups were identical, just as the stated hypothesis is not evidence that they differed.
9. Statistical Methods Explained
The registry names a generalized linear mixed model (GLMM) for the primary analysis and describes the outcome as a mean continuous measure. It also says the analysis used an intention-to-treat approach, including all observations for all relevant time points used in the calculation. The model’s detailed specification and numerical results are not reported in the registry record.
What a mixed model can do
General statistical explanation: a mixed model can represent the relationship between an outcome and study group, time, and other specified terms while accounting for correlation among repeated measurements from the same participant. Measurements on one person are usually related to one another, rather than behaving like observations from entirely different people. A model that recognizes this structure can estimate group patterns over time while representing within-participant dependence.
The label generalized linear mixed model does not, on its own, reveal the distribution, link function, fixed effects, random effects, covariance structure, or adjustment variables chosen by the investigators. Those details are not reported in the registry record. It is therefore not possible to reconstruct the exact fitted model or independently assess whether its assumptions were appropriate from the registry description alone.
What intention to treat means
General statistical explanation: an intention-to-treat analysis aims to compare participants according to the groups to which they were assigned, rather than reclassifying them according to treatment received or excluding them because they did not follow the intervention as intended. This approach preserves the logic of random assignment when implemented appropriately. The registry says the primary analysis included all observations for all relevant time points used in the calculation. That wording does not specify whether every randomized participant had complete observations, how missing values were handled, or whether any participants were excluded from the model.
In a repeated-measures model, participants may contribute available observations even when not every scheduled measurement is present, depending on the model and its assumptions. This is general context, not a statement about the exact missing-data procedure used in this study. The registry does not report the amount or pattern of missing outcome data, the assumptions made about missingness, or any sensitivity analyses.
How to read the endpoint summary
The registry identifies the endpoint parameter as a mean and the dispersion measure as a standard deviation. A mean describes the average value in a group, while a standard deviation describes the spread of individual values around that average. These are descriptive summaries; neither one alone quantifies uncertainty in a comparison between groups. A standard error or confidence interval would address uncertainty in an estimated mean or contrast, but such values are not reported for the primary result in the registry record.
Change from baseline is a within-participant outcome: it relates a later measurement to the participant’s initial value. A randomized comparison of changes asks whether average change differs between assigned groups. In general, the estimated contrast is more informative for the intervention question than a within-group change alone, because change in either group may reflect multiple influences over time. The registry does not provide the group-specific changes or the between-group contrast.
Precision and uncertainty
General statistical explanation: a confidence interval communicates the statistical precision of an estimate. A narrower interval indicates greater precision under the model and analysis assumptions; a wider interval indicates that a broader range of values remains compatible with the data. A p-value does not measure the size or importance of an effect. It addresses how compatible the data are with a particular null model, again under the analysis assumptions. Neither a confidence interval nor a p-value for the primary endpoint is reported in the registry record, so precision cannot be judged numerically.
The registry includes a description of planning assumptions for a sample-size illustration: two-sided significance level 0.05, equal allocation, a normal approximation, and an effect defined as a stated fraction of the observed effect. It says that such illustrations are based on the observed effect and are not the trial’s own design. The record does not report numerical sample-size illustration results in the information available for this analysis. These planning assumptions should not be read as observed results or as a justification for the original sample size. The sample-size justification for the trial is not reported in the registry record.
General statistical explanation: over-dispersion occurs when outcome variability is greater than a model’s assumed distribution allows. If present and unaddressed, it can make standard errors and related uncertainty estimates unreliable. Whether over-dispersion is relevant depends on the outcome distribution and model. The registry does not provide enough model detail or diagnostic information to determine whether it was assessed, and no claim about its presence or absence is warranted.
What cannot be reconstructed
The registry identifies one analysis and lists 24 outcome measures, but it does not give a complete statistical analysis plan. It does not report the model formula, effect coding, covariates, estimation method, degrees-of-freedom approach, diagnostic checks, or handling of protocol deviations. Interim analyses and stopping rules are not reported in the registry record. The method used to control multiplicity across outcomes or time points is also not reported.
These limits do not imply that the analysis was performed incorrectly. They mean that the record does not include enough detail to reproduce the analysis or judge all its assumptions. The available description supports a high-level account of the intended primary endpoint, the use of a mixed model, and the stated intention-to-treat population, but not a full audit of the model or its results.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists 24 outcome measures and identifies a primary outcome of change in HbA1c from baseline. It also describes secondary outcomes involving blood pressure, body mass index, and diabetes self-management. The study description refers to clinical and self-management outcomes at 3 and 6 month follow-up. With multiple outcomes and time points, statistical interpretation can be affected by the number of comparisons considered. As a general principle, the more hypotheses examined, the greater the chance of at least one apparently unusual result when all null hypotheses are true. Methods for controlling or otherwise addressing multiplicity are not reported in the registry record.
The registry states that one analysis was recorded. It does not clarify whether this refers to one posted analysis for a particular outcome or to a complete analysis plan covering all listed outcomes. It does not report a prespecified hierarchy among secondary outcomes, an adjustment method, or whether the primary comparison was selected before outcome data were examined. Interim analyses are not reported in the registry record.
For the primary endpoint, the registry describes an intention-to-treat analysis that included all observations for all relevant time points used in the calculation. This is the available description of the analysis population. The record does not state the number of participants contributing HbA1c data at each time point, the amount or pattern of missingness, reasons for missing measurements, or the method used to handle missing data. It also does not report sensitivity analyses that might assess whether conclusions depend on missing-data assumptions.
General statistical context: intention-to-treat describes the principle for retaining randomized group assignment in the comparison, while missing-data methods describe how unavailable measurements are handled. These concepts are related but not interchangeable. The registry’s statement about including all relevant observations does not establish that all participants had complete follow-up, nor does it identify a particular imputation or likelihood-based procedure. The sample-size justification and the handling of any protocol deviations are not reported in the registry record.
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 |
|---|---|---|---|
| Yo Puedo | 0 | 26 | 0.0% |
| Wait-list Control | 1 | 21 | 4.8% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Yo Puedo | 0 of 26 |
| Wait-list Control | 0 of 21 |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 5% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Yo Puedo | 8 of 26 |
| Wait-list Control | 2 of 21 |
Most frequent serious adverse event terms
| Event term | Organ system | Yo Puedo | Wait-list Control |
|---|---|---|---|
| Hypoglycemia | Endocrine disorders | 0 of 26 | 1 of 21 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Yo Puedo | Wait-list Control |
|---|---|---|---|
| Hypoglycemic | Endocrine disorders | 5 of 26 | 2 of 21 |
| hyperglycemia | Endocrine disorders | 3 of 26 | 0 of 21 |
Serious events with the highest arm-level rate: hypoglycemia (4.8%).
The registry reports serious adverse events for 26 participants at risk in the Yo Puedo group and 21 in the wait-list control group. There were 0 serious adverse events among 26 at risk in Yo Puedo and 1 among 21 at risk in the wait-list control group. Deaths were 0 in both groups. These are the posted counts; they do not, by themselves, establish that the groups differed in safety.
For other adverse events, the record lists 8 affected participants among 26 at risk in Yo Puedo and 2 among 21 at risk in the wait-list control group. The registry lists hypoglycemia as the top serious adverse event term, with 4.8%. The denominator and precise basis for that percentage are not reported in the registry record. The adverse-event figures do not provide event descriptions, severity grades beyond the serious/non-serious classification, timing, or judgments about relatedness to the intervention.
General statistical context: adverse-event counts in a small pilot study are descriptive and can be imprecise, particularly for uncommon events. Counts of participants with at least one event are not necessarily counts of all event episodes. The registry figures should therefore be read as the recorded event summaries, not as a complete characterization of risk or as proof of a causal relationship. Additional safety detail is not reported in the registry record.
12. What the Result Does, and Does Not, Mean
The registry record allows a reader to identify the question the investigators set out to study: whether a culturally adapted diabetes self-management education program with pictorial text messaging was associated with different HbA1c change than a wait-list condition. It also documents a randomized parallel design, no masking, the named primary endpoint, and use of a generalized linear mixed model in an intention-to-treat analysis. Those details describe the study framework, not the direction or size of the outcome result.
The primary numerical outcome is not reported in the registry record. As a result, the effect estimate, its precision, and the evidence for or against a difference between groups cannot be assessed. The absence of a posted estimate should not be interpreted as a zero effect, a positive effect, or a negative effect. Nor does the hypothesis in the study description establish the result.
The study was described as a pilot with aims that included feasibility, acceptability, fidelity, and preliminary efficacy. This framing is important for interpreting the scope of what the trial could address. A pilot can provide information about whether procedures and program delivery can be carried out, but a definitive conclusion about clinical outcomes requires outcome estimates and uncertainty that are not available in the registry record. Numerical findings for the feasibility and acceptability aims are also not reported there.
General statistical context: an estimated effect and its confidence interval are needed to understand both the apparent size of a difference and the range of values consistent with the data. A single significance result, even if available, would not by itself establish clinical importance. Here, the primary estimate and inferential statistics are not reported, so neither statistical nor clinical importance can be evaluated from this record.
The design and enrollment information can help describe the study, but they cannot fill in the missing outcome result. The recorded enrollment is 47, while the study description refers to randomizing 40 adults; the record does not explain this distinction. The safety counts provide a separate description of adverse events and should not be substituted for the unreported primary efficacy comparison. The most defensible interpretation is limited: the registry documents the planned evaluation and analysis approach, but does not report the numerical primary findings needed to assess the observed HbA1c comparison.
13. Why This Trial Matters Statistically
Statistically, this study is notable for combining a randomized comparison with a pilot focus on adapting and delivering a behavioral program in a specific care context. The registry describes collaboration with diabetes experts, clinic administrators, health professionals, and adults with diabetes in Mexico City. It also identifies implementation fidelity, attendance, attrition, and acceptability as important evaluation targets. Such outcomes can inform whether a larger evaluation is practical, apart from whether a clinical endpoint differs between groups.
The primary outcome is repeated over time, and the registry names a generalized linear mixed model. In general, mixed models can account for dependence among measurements from the same participant, which is relevant when a study collects outcomes at multiple visits. The registry’s intention-to-treat description also signals an aim to analyze participants in relation to their randomized group. These choices are statistically relevant, although the model specification and missing-data procedures are not reported in the registry record.
The design is described as randomized, but the registry does not report sequence generation or allocation concealment details. No masking is recorded. These details matter when assessing possible sources of bias and understanding how securely assignment was implemented. The record also does not report a sample-size justification, so the intended precision or detectable effect for the study cannot be assessed from the design information.
A further statistical issue is the breadth of outcomes: the record lists 24 outcome measures and identifies several clinical and behavioral domains. Without a reported multiplicity strategy or a clear analysis hierarchy, readers cannot determine how the investigators planned to interpret multiple comparisons. Most importantly, the numerical primary outcome estimate and its uncertainty are not reported in the registry record. Statistical methods are most informative when readers can connect the model description to an estimate, a measure of precision, and a transparent account of the analysis population.
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 for interpreting the primary outcome is that the numerical result is not reported in the registry record. The record names the endpoint and analysis method but gives no group-specific changes, between-group estimate, confidence interval, or p-value. Consequently, the size, direction, and precision of the primary comparison cannot be described.
Several design and analysis details are also absent. The registry does not report how the randomization sequence was generated or concealed, the analysis model’s full specification, the handling of missing data, the number of participants with outcome measurements at each visit, or sensitivity analyses. Although no masking is recorded, the extent to which outcome assessment or other study procedures were blinded is not separately described. A sample-size justification, interim analysis plan, and multiplicity approach are not reported in the registry record.
The study description says 40 adults would be randomized, while recorded enrollment is 47. The reason for this difference is not reported. The safety population counts are available, but those figures do not provide the primary outcome denominators at follow-up. The registry also lists a large set of outcome measures relative to the pilot framing, without reporting how secondary analyses were prioritized or adjusted for multiple comparisons.
Finally, the registry states aims related to feasibility, acceptability, fidelity, and preliminary efficacy, but numerical results for the implementation and interview outcomes are not included in the record. These limitations concern what can be evaluated from the registry record; they do not establish that the study lacked these data or analyses outside the record.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Yo Puedo! Diabetes Self-Management Education + mHealth in Mexico City — NCT03159299.
- Registry record last updated 2020-04-27; status last verified 2020-04.
- Results first posted 2020-04-27.
- 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 record describes NCT03159299, Yo Puedo! Diabetes Self-Management Education + mHealth in Mexico City, as a completed, randomized, parallel behavioral study with no masking. The recorded enrollment is 47, and the listed phase is NA. The study description says 40 adults would be randomized to the adapted Yo Puedo program with mHealth or a wait-list control.
The primary endpoint is change in HbA1c from baseline, with baseline, 3, and 6 months listed as the timeframe. The record says the primary analysis used a generalized linear mixed model and an intention-to-treat approach. Numerical primary outcome results and their uncertainty are not reported in the registry record. The record also lists secondary clinical and self-management outcomes and adverse-event counts. It describes aims involving feasibility, acceptability, and implementation fidelity, but does not report numerical findings for those aims.