Orchestra Pregnancy Observational Study in Poland: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Orchestra Pregnancy Observational Study in Poland (NCT01779141), a registered phase not stated study. The primary outcome is HbA1c.

2. Clinical Question

In practical terms, the study was intended to document pump use around pregnancy and changes in HbA1c over that period among the enrolled women. It also lists Large for Gestational Age and Unhealthy Babies as secondary outcomes. The registry record does not report results for those outcomes. The study can therefore be described by its intended population, treatment context and outcome definitions, but its clinical findings cannot be assessed from the information recorded about the outcomes.

3. Trial Design

This is a multi-center observational study in Poland, registered as NCT01779141. Its title and study description concern women with type 1 diabetes mellitus who used Paradigm insulin pumps donated by the Wielka Orkiestra Świątecznej Pomocy Foundation. The registry record lists Medtronic MiniMed, Inc. as sponsor, an enrollment of 481, a start date of 2013-05, a primary completion date of 2017-08, and a status of COMPLETED.

The stated aim is to document insulin pump therapy before, during and after pregnancy. The record includes CSII, with or without CGM, and describes the study scope as including sensor-augmented pump therapy. The arm description identifies a CSII group; it does not describe a separate control group. Allocation is not stated. The registry record therefore does not support reading the study as a randomized treatment comparison or as a comparison between equivalent assigned groups.

HbA1c is identified as the primary outcome. Its timeframe runs from the preconception phase to 6 weeks after delivery, and its description concerns change from baseline to after delivery. The primary-outcome population includes participants with both measurements available. Large for Gestational Age and Unhealthy Babies are named as secondary outcomes. The record lists four outcome measures, but does not report the results for the primary or secondary outcomes.

The registry record lists no analyses. Details such as the recruitment process, participant characteristics, exact visit schedule, adherence, protocol deviations and statistical analysis plan are not reported in the registry record. The listed enrollment describes the study record; it does not establish how many participants contributed data to the primary outcome. Because the design is observational and no comparator is described, changes over time should not be interpreted as evidence that pump therapy caused any outcome.

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

Analysis population for the primary outcome, as defined in the registry: Participants who have both baseline HbA1C and after delivery HbA1C available.

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 HbA1c, measured over from preconception phase to 6 weeks after delivery.

The primary endpoint is HbA1c, measured as a percentage and summarized using a mean and standard deviation. The registry description focuses on change from baseline to after delivery, with the timeframe extending from the preconception phase to 6 weeks after delivery. The primary-outcome population is restricted to participants with both baseline and after-delivery HbA1c available.

As general clinical context, HbA1c is a measure used to characterize glycemic exposure over time. It is not a direct measure of pregnancy or neonatal outcomes. Tracking it across the stated period can describe how the measured value changes in the participants with the required measurements. A mean describes the central value in that analysis population, while a standard deviation describes the spread of individual measurements around the mean. Neither statistic alone shows how precise an estimated change is; a confidence interval or other uncertainty measure would be needed for that assessment.

The registry record does not report the baseline or after-delivery means, the mean change, its standard deviation, or an interval estimate. It also does not report how many participants had both measurements. The endpoint definition is therefore available, but the size and precision of the HbA1c change are not reported in the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry record identifies HbA1c as a continuous primary outcome, to be summarized as a mean with standard deviation. It does not report a statistical analysis or its results. The explanations below describe general statistical concepts relevant to this outcome; they should not be taken as methods confirmed for this study.

What does a mean change describe?

For a continuous measure, a mean is the arithmetic average of the observed values in the analysis population. A change score describes the difference between a participant's later measurement and an earlier measurement. When the same participants contribute both measurements, the changes are paired: each participant's later value is linked to that participant's baseline value. The average of those individual changes describes the average within-participant change among those included. This is conceptually distinct from comparing unrelated group averages.

The registry record specifies baseline and after-delivery HbA1c availability as a condition for inclusion in the primary-outcome population. That indicates the intended availability of paired measurements, but does not establish which calculation or model was used. The exact handling of intermediate measurements, timing variation, or participants with incomplete follow-up is not reported in the registry record.

What does the standard deviation tell the reader?

A standard deviation describes the spread of observations around a mean. It reflects variability among the measured values, not the precision of the estimated mean. A standard deviation can be large even when the mean is estimated precisely in a sufficiently informative dataset; conversely, a small standard deviation does not by itself establish precise estimation. Precision is commonly conveyed with a confidence interval or another uncertainty measure. The registry record does not report the standard deviation or an interval estimate for the primary outcome.

How would a confidence interval be interpreted?

In general, a confidence interval gives a range of values compatible with the data and the assumptions of the statistical method. Its width communicates precision: a narrower interval indicates a more precise estimate than a wider interval, all else equal. The interval does not correct for bias from missing data, confounding, or an unsuitable analysis. No confidence interval for HbA1c change is reported in the registry record, so its precision cannot be assessed from the recorded outcome information.

Why does the observational design matter?

In a randomized trial, random assignment is intended to balance measured and unmeasured characteristics across treatment groups, on average. In this observational study, allocation is not stated and the record does not describe a comparator group. Participants' pump use was not described as assigned by randomization. As a general matter, factors related to treatment use and pregnancy outcomes can influence an observed association. Statistical adjustment can address measured factors under suitable assumptions, but cannot guarantee removal of unmeasured confounding. The registry record does not report an adjusted model, covariates, or other analysis details.

Repeated measurements can be statistically dependent because measurements from the same participant tend to be related. An analysis that treats them as independent may misstate uncertainty. A paired analysis or a model for repeated measurements can account for that dependence, depending on the data and question. The registry record does not identify which approach, if any, was used. It also does not report whether the analysis used only baseline and after-delivery values or incorporated additional measurements during the stated period.

What do the planning assumptions mean?

The registry description gives assumptions for planning illustrations: a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. It describes the target effect as a stated fraction of the observed effect. These are assumptions for an illustrative sample-size calculation, not evidence of the study's own design or an analysis of its results. The record does not report a numerical observed effect or the resulting sample-size values. Equal allocation between two arms is not a description of the recorded study structure, which identifies a CSII group and no like-for-like control group.

The same description distinguishes time-to-event planning, which uses the total number of events, from other planning illustrations, which use participants per arm. This is a general distinction between event-driven planning and planning based on the number of participants. It does not establish that the primary HbA1c outcome was analyzed as a time-to-event endpoint; the registry identifies HbA1c as continuous. Sample-size illustrations based on an observed effect are planning exercises, not observed power and not proof that an outcome was detected.

What can be concluded from the registered methods information?

The record permits a limited description of the endpoint type, summary measure, timeframe and primary-outcome population. It does not report the statistical model, test, confidence interval method, assumptions checked, covariate adjustment, handling of repeated measurements, or analysis results. The registry record also lists no analyses. Consequently, readers cannot verify how the endpoint definition was implemented, reproduce the analysis, or assess the robustness of a reported estimate. General statistical methods can explain what would matter for this study, but cannot fill in these unreported details.

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("CSII")
n   <- c(219)
m   <- c(-0.8)
sp  <- c(1)
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  CSII  219  -0.800  1.000  -0.933  -0.667

11. Multiplicity, Missing Data and Analysis Populations

The registry record lists four outcome measures and identifies HbA1c as the primary outcome. It names Large for Gestational Age and Unhealthy Babies as secondary outcomes. It does not report results for these outcomes, a prespecified hierarchy among all measures, or a plan for handling multiple statistical tests. Whether any multiplicity adjustment was used is not reported in the registry record.

Multiplicity matters because testing several outcomes or several versions of an outcome can increase the chance of finding an apparently notable result by chance. This is a general statistical concern, not a claim that the study conducted a particular set of tests. Without the analysis plan and reported results, readers cannot determine how many tests were performed, whether outcomes were selected for reporting, or how any multiplicity was addressed.

The primary endpoint is defined for participants with both baseline and after-delivery HbA1c available. This is a complete-measurement population for that outcome. The record does not report the number with both values, reasons for missing measurements, whether missingness differed across participants, or how missing data were handled. It also does not report whether analyses used other populations, such as all enrolled participants.

Missingness can affect an estimate if the participants with complete measurements differ in relevant ways from those without them. Statistical approaches can make assumptions about missing observations, but the validity of those approaches depends on the missing-data process and the assumptions used. Those details are not reported in the registry record. The study status of COMPLETED and the enrollment entry do not establish completeness of outcome follow-up or the size of the population contributing to each outcome.

12. Safety Results

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

Deaths

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 0% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: abortion spontaneous (5.8%), jaundice neonatal (5.6%), premature labour (5.4%), foetal distress syndrome (3.5%), threatened labour (3.5%).

The registry lists safety figures for the CSII group, described as participants using CSII with or without CGM. It records 481 at risk for serious adverse events and 181 under serious adverse events affected. For other adverse events, it records 481 at risk and 11 affected. The record lists 1 death. These are registry counts; the record does not give enough detail to determine from these figures alone how events were defined, whether individuals could contribute to more than one category, or the timing of events.

The most frequently listed serious-event terms and their recorded percentages are Abortion spontaneous, 5.8%; Jaundice neonatal, 5.6%; Premature labour, 5.4%; Foetal distress syndrome, 3.5%; Threatened labour, 3.5%; and Caesarean section, 2.3%. The registry record does not state the denominator or method used for these percentages in the information available for these figures. They should not be treated as rates over a specified follow-up period.

These safety entries do not establish that pump use caused an event, nor do they provide a comparison with an untreated or alternative-treatment group. The record does not report attribution, event timing, severity details beyond the serious-event category, or the cause of the listed death. The figures describe what the registry records; further interpretation is limited by the absence of those details and of a comparator.

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

The study record documents an observational effort to describe insulin-pump use around pregnancy among women with type 1 diabetes in Poland. It identifies HbA1c change from baseline to after delivery as the primary outcome and names pregnancy-related outcomes as secondary measures. These details explain what the registry intended to follow, but the record does not report the outcome estimates needed to judge what was observed.

In particular, no numerical HbA1c change, standard deviation, confidence interval, or statistical test result is reported in the registry record. The record also does not report results for Large for Gestational Age or Unhealthy Babies. It is therefore not possible to say from the registry outcome information whether HbA1c increased, decreased or remained similar, or to assess the magnitude and precision of any change.

Even if a within-participant change were reported, it would describe change over time among the participants included in that analysis. It would not, by itself, establish that pump therapy caused the change. The study is observational, allocation is not stated, and no like-for-like control group is described. Changes in pregnancy, clinical care, participant characteristics or follow-up could be relevant alternative explanations. These are general cautions about causal interpretation, rather than findings reported by this study.

The primary outcome also applies only to participants with both baseline and after-delivery HbA1c measurements. The record does not report how this analysis population relates to the enrollment, how many measurements were missing, or whether missingness could affect the result. Safety figures can be read as recorded counts and listed terms, but they likewise do not establish treatment causation or comparative safety.

The record therefore supports a description of the study's purpose, population, outcome definitions and some safety entries. It does not support a conclusion about the size, precision or cause of an HbA1c change, or a comparative conclusion about pregnancy outcomes. The registry status of COMPLETED should not be confused with a reported statistical result.

14. Why This Trial Matters Statistically

Statistically, this study is notable for asking a longitudinal question in a specific clinical setting: pump use around pregnancy among women with type 1 diabetes who benefited from a pump donation program. The primary outcome is a continuous measure observed at baseline and after delivery, and the specified primary-outcome population requires both measurements. That definition makes the link between repeated observations and missing follow-up central to interpreting any estimate.

The observational design is equally important. A record describing a treatment group without a like-for-like control does not support the same treatment-effect interpretation as a randomized comparison. Statistical analysis can describe changes and explore associations, but causal claims require assumptions and information beyond a before-and-after pattern. Allocation is not stated, and the registry record does not describe an adjusted analysis or its assumptions.

The study also spans preconception, pregnancy and the period after delivery, which makes timing and measurement definitions relevant. The registry names additional pregnancy-related outcomes, but does not report their results. Readers would need the actual estimates, uncertainty measures, analysis population and missing-data details to judge how informative the findings are.

The record's safety entries are another reminder that event counts and labels need context. Without clear denominators, timing, attribution and a suitable comparison, counts describe recorded events but do not quantify a comparative treatment effect. More broadly, registry completion and enrollment are not substitutes for outcome reporting. This distinction is useful when evaluating any clinical study: a clear question and endpoint definition are valuable, but conclusions depend on transparent results and methods.

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 are specific to the information recorded for this study. It is observational, allocation is not stated, and the record describes a CSII group without a like-for-like control group. The results therefore cannot be interpreted as a randomized comparison. The registry record does not describe factors that could influence both pump use and pregnancy outcomes, or any analysis intended to account for them.

The primary outcome is limited to participants with both baseline and after-delivery HbA1c measurements. The record does not report how many participants met that requirement, the extent or reasons for missing measurements, or whether missingness was assessed. The listed enrollment cannot be assumed to equal the primary-outcome analysis population.

The record gives an endpoint timeframe and summary measure but does not report the HbA1c values, change estimate, uncertainty interval, or analysis method. It also names secondary outcomes without reporting their results. The registry record lists no analyses, so the statistical plan, model, handling of repeated measurements, covariates and multiplicity approach are not available for assessment.

The study concerns women benefiting from a donation program and using specified Paradigm pump models in Poland. The record does not provide participant characteristics or detail the recruitment process, so the extent to which the enrolled population represents other settings or populations cannot be assessed. This limits the scope of generalization from the registry description.

Safety interpretation is also constrained: event definitions, attribution, timing, percentage denominators and the cause of the listed death are not reported in the registry record. These gaps do not show that an event was or was not related to treatment; they limit what can be inferred from the recorded safety entries.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Orchestra Pregnancy Observational Study in Poland — NCT01779141.
• Registry record last updated 2020-02-05; status last verified 2020-01.
• Results first posted 2019-07-10.
• 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

NCT01779141 is a completed multi-center observational study in Poland concerning insulin-pump use before, during and after pregnancy among women with type 1 diabetes who benefited from the Orchestra donation of Paradigm pumps. The registry lists Medtronic MiniMed, Inc. as sponsor, enrollment of 481, a start date of 2013-05 and primary completion of 2017-08.

HbA1c is the primary outcome, described as change from baseline to after delivery and summarized as a mean with standard deviation. The primary-outcome population requires both measurements. Large for Gestational Age and Unhealthy Babies are named as secondary outcomes. The record lists four outcome measures and no analyses.

Outcome estimates and statistical results are not reported in the registry record. The record describes a CSII group, with or without CGM; allocation is not stated, and no like-for-like control group is described. Safety entries include serious and other adverse-event counts, a death count and listed serious-event terms, but interpretation is limited by missing detail on context, denominators and attribution.