An Observational Study on the Natural Course of Chronic Pancreatitis: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for An Observational Study on the Natural Course of Chronic Pancreatitis (NCT04574297), a registered phase not stated study. The primary outcome is the Number of Patients Developing Pancreatic Insufficiency.

2. Clinical Question

3. Trial Design

The record describes an observational study of the natural course of chronic pancreatitis and the possible contribution of genetic and environmental factors. Changhai Hospital is listed as the sponsor. The study start date is 2011-01-01, the primary completion date is 2020-05-31, and the status is active, not recruiting. Enrollment is listed as 798.

The four groups named in the registry record are G+/E+, G-/E+, G+/E-, and G-/E-. The record does not define the group labels, explain how participants were classified, or report whether people could change categories over time. It also does not give details about recruitment, the clinical setting, eligibility, or the schedule of assessments. Those details are not reported in the registry record.

Because the study is observational, the named groups should not be read as randomized treatment arms. The registry record explicitly indicates that the allocation is not stated and that the arms are not a like-for-like control comparison. Differences between groups, if estimated, could reflect differences in participant characteristics or other factors as well as the exposures of interest. The record does not report a statistical adjustment plan or any group-comparison results.

The primary endpoint concerns development of pancreatic insufficiency over 10 years. Death is listed as a secondary outcome. Although the record lists genetic sequencing and smoking and alcohol assumption as interventions, it does not describe the procedures or measurements in enough detail to establish how these were used in the study.

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

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 the Number of Patients Developing Pancreatic Insufficiency, measured over 10 years.

The primary endpoint is the number of participants developing pancreatic insufficiency during a 10-year timeframe. The registry description classifies this outcome into three categories: diabetes and steatorrhea, diabetes only, or steatorrhea only. The unit is participants, and the measure is a count of participants.

This endpoint is relevant to a study of chronic pancreatitis because it records the development of complications identified in the registry as pancreatic insufficiency. In general, counting participants who experience an outcome gives a direct description of how many people meet the outcome definition. It does not, by itself, describe when each event occurred, how long participants were followed, or how risk differs between groups.

The record does not report the number of participants in each endpoint category, the number without pancreatic insufficiency, or the analysis used to compare categories or groups. It also does not clarify whether the three categories are mutually exclusive for the full study period or how the endpoint was assessed over time. These details are not reported in the registry record. The stated 10-year timeframe identifies the endpoint’s registered observation period; it does not establish that every participant completed that duration of follow-up.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What the primary measure represents. The primary endpoint is a participant count, categorized by the registry as diabetes and steatorrhea, diabetes only, or steatorrhea only. For a count endpoint, a complete analysis would need to state the number meeting each category and the relevant denominator. The registry record does not report those outcome counts or denominators. It also does not report whether the primary analysis treated categories separately or combined them.

Association in an observational study. General statistical principle: observational studies compare outcomes among people whose exposures or characteristics were observed rather than assigned at random. Such comparisons can identify patterns, but group membership may be related to other characteristics that also affect outcomes. This is called confounding. Adjustment for measured confounders can help address some differences, but it cannot guarantee removal of bias, especially from factors not measured or not included in a model. The registry record does not report a confounder set, adjustment model, or primary analysis method.

Interpreting group comparisons. The listed G+/E+, G-/E+, G+/E-, and G-/E- labels indicate categories used in the registry record, but their definitions are not reported there. Without those definitions, it is not possible to explain what a positive or negative label denotes or whether the groups represent specific genetic and environmental exposures. The record also does not identify a reference group or report a contrast between groups. The groups should not be treated as randomized arms: allocation is not stated, and the record cautions that they are not a like-for-like control comparison.

Counts, rates, and time. General statistical principle: a count describes how many events or participants were observed, while a rate or risk requires an appropriate denominator and a defined observation period. Time-to-event methods additionally use event timing and account for differing follow-up. The primary endpoint is registered with a 10-year timeframe, but follow-up duration for individual participants, censoring, and event dates are not reported in the registry record. A count alone cannot show when pancreatic insufficiency developed or account for different observation times.

Uncertainty and precision. General statistical principle: a confidence interval describes the range of effect values compatible with the data and statistical model, and its width communicates precision. A point estimate without an interval can conceal substantial uncertainty; an interval does not remove bias or establish causality. The registry record does not report a primary effect estimate or confidence interval. It also does not report a primary hypothesis test or p-value.

Planning assumptions are not trial results. General statistical principle: sample-size planning uses assumptions about the effect to detect, the significance level, allocation, and analysis method. A planning illustration is not the same as a sample-size justification used to design a study, and it is not observed power. The registry record describes a planning illustration based on an observed effect, with a two-sided significance level of 0.05, equal allocation, and a normal approximation. The target effect is described as a stated fraction of the observed effect. These assumptions do not establish that the study itself used them for design or analysis. The registry record does not report a study-specific sample-size justification. Any planning values should be read as hypothetical illustrations, not as observed results or evidence of adequate power.

Multiplicity and categories. General statistical principle: testing several outcomes, groups, or contrasts can increase the chance of at least one apparently notable result. A prespecified testing hierarchy or multiplicity adjustment may be used to manage that issue. The registry record names a primary endpoint and Death as a secondary outcome, but does not report a testing hierarchy or multiplicity procedure. The endpoint’s three categories also make the analysis definition important; the record does not state whether they were analyzed separately, combined, or ordered.

Analyses posted. The registry record lists zero analyses. This means that the record does not provide an analysis result to interpret for the registered outcomes. It does not establish what analyses may have been conducted outside the registry record. The statistical model, covariates, missing-data approach, and analysis population are not reported in the registry record.

10. Exact Estimates for Each Arm

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

R code and output

arm    <- c("G+/E+ Group", "G-/E+ Group", "G+/E- Group", "G-/E- Group")
n      <- c(180, 263, 230, 125)
events <- c(82, 130, 55, 36)
for (i in seq_along(n)) {
  ci <- binom.test(events[i], n[i])$conf.int          # Clopper-Pearson exact interval
  cr <- qbeta(c(0.025, 0.975), 1 + events[i], 1 + n[i] - events[i])   # Bayesian, uniform Beta(1,1) prior
  wi <- (function(x, n) { p <- x / n; z <- qnorm(0.975); d <- 1 + z^2 / n
    c((p + z^2 / (2 * n) - z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d, (p + z^2 / (2 * n) + z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d) })(events[i], n[i])
  cat(sprintf("ARM|%s|%d|%d|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f\n", arm[i], n[i], events[i], 100 * events[i] / n[i],
              100 * ci[1], 100 * ci[2], 100 * wi[1], 100 * wi[2], 100 * cr[1], 100 * cr[2]))
}

ARM  G+/E+ Group  180  82  45.6  38.1  53.1  38.4  52.8  38.4  52.9
ARM  G-/E+ Group  263  130  49.4  43.2  55.6  43.4  55.4  43.4  55.4
ARM  G+/E- Group  230  55  23.9  18.6  30.0  18.9  29.8  18.9  29.8
ARM  G-/E- Group  125  36  28.8  21.1  37.6  21.6  37.3  21.6  37.3

11. Multiplicity, Missing Data and Analysis Populations

The registry record names a primary endpoint and lists Death as a secondary outcome. It does not report a statistical testing hierarchy, a multiplicity adjustment, or how the three pancreatic-insufficiency categories were handled in testing. When multiple outcomes or group comparisons are examined, general statistical practice is to define which analyses are primary and whether any adjustment is planned. Without that information, the intended control of false-positive findings is not reported in the registry record.

Missing-data methods are also not reported in the registry record. There is no description of how missing outcome assessments, incomplete follow-up, or participants lost to follow-up were handled. The 10-year timeframe does not establish that every participant had complete observation for that period. The record does not report the number with missing primary outcome data or whether any imputation was used.

The analysis population is not reported in the registry record. The listed enrollment and the group-specific counts in the adverse-event information do not, on their own, establish which participants contributed to a primary endpoint analysis. The registry record lists zero analyses, so it gives no analysis set, exclusions, or model population to assess. As a result, the completeness and representativeness of the posted outcome data cannot be evaluated from this record.

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.

The adverse-event information lists serious events and other events by group. For serious events, the number affected is 0 in each group; the corresponding numbers at risk are 180 in G+/E+, 263 in G-/E+, 230 in G+/E-, and 125 in G-/E-. For other events, the number affected is also 0 in each group, with the same group-specific counts at risk. The registry record lists no serious-event terms.

Deaths are presented separately in the group information: 6 in G+/E+, 9 in G-/E+, 4 in G+/E-, and 5 in G-/E-. Death is also named as a secondary outcome. These are descriptive counts, not comparative estimates. The record does not report causes, timing, attribution, or statistical comparisons for deaths.

Zero affected in the event fields means no events were recorded in those fields for the listed groups. It does not establish that there were no unrecorded events or that event ascertainment was complete. The record does not describe how adverse events were collected, defined, or monitored. These figures should not be used to compare safety between groups or infer a causal relationship.

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

The registry record establishes that an observational study was registered to examine genetic and environmental factors in the natural course of chronic pancreatitis. It identifies pancreatic insufficiency as the primary endpoint, categorizes it into three clinical presentations, and gives a 10-year timeframe. It also lists Death as a secondary outcome and identifies four groups in the adverse-event information.

It does not report the primary endpoint counts, an effect estimate, a confidence interval, a statistical test, or an adjusted comparison. Therefore, the record cannot quantify an association between the listed groups and development of pancreatic insufficiency. It also cannot establish whether any observed difference would be precise, statistically distinguishable from chance, or clinically important.

General statistical principle: an observational association is not the same as a causal effect. Even a difference between groups may reflect other differences among participants, measurement practices, or follow-up. The registry record does not report enough detail about exposure definitions, participant characteristics, outcome assessment, or adjustment to evaluate those issues.

The death counts and the zero affected counts in the serious and other event fields are descriptive registry entries. They do not establish why deaths occurred, whether outcomes were completely captured, or whether the groups differed in risk. They should not be interpreted as proof for or against a causal relationship.

In short, the registered question and endpoint are identifiable, but the posted record does not provide the outcome analysis needed to answer that question. A reader can describe the study’s scope and the event counts listed in the record, but cannot infer the magnitude or direction of an association from the primary endpoint because its results are not reported in the registry record.

14. Why This Trial Matters Statistically

This study raises a statistical question that is important for observational research: how to distinguish associations with disease progression from differences that arise because participants have different characteristics or exposures. The registry record frames chronic pancreatitis progression in relation to genetic and environmental factors, and identifies pancreatic insufficiency as its primary endpoint.

The endpoint definition illustrates why clarity about outcome categories matters. The registry separates diabetes and steatorrhea, diabetes only, and steatorrhea only. Analyses can answer different questions depending on whether those categories are presented individually or combined. The registry record does not report which approach was used, so the intended interpretation of the categories remains unclear.

The record also shows why event counts need context. Counts alone do not communicate timing, duration of observation, or the influence of incomplete follow-up. In general, those features matter when outcomes can occur over time and participants may have different observation periods. The registry gives a 10-year endpoint timeframe but does not report participant-level follow-up or primary outcome results.

Finally, the four named groups do not constitute a randomized comparison. Understanding an observational contrast requires clear definitions of exposure, group membership, potential confounders, and the analysis used. Those details and the primary results are not reported in the registry record. The study is therefore statistically notable for the question it set out to examine, while the record itself leaves the key comparative evidence unavailable.

15. Limitations

• The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
• Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.

Several limitations specific to this registry record constrain interpretation. The labels G and E are not defined, and the record does not describe how genetic status or environmental exposures were determined. It names genetic sequencing and smoking and alcohol assumption, but provides no measurement procedures, timing, or exposure categories. As a result, the four group labels cannot be translated into clearly defined exposures from the registry record alone.

The primary endpoint is described by three categories, but the record does not state how cases were identified, whether categories could overlap, or how the counts were analyzed. Primary outcome results are not reported in the registry record. There are no effect estimates, uncertainty intervals, or group comparisons to assess.

The 10-year timeframe does not specify individual follow-up. The record does not describe censoring, loss to follow-up, missing outcome data, or the number of participants contributing to each endpoint analysis. It also does not report participant characteristics, eligibility criteria, or the analysis population.

Because this is observational and the allocation is not stated, the groups are not a like-for-like randomized comparison. The registry record does not report a confounding-control strategy or statistical model. The posted death and adverse-event counts are descriptive and lack information about timing, cause, and ascertainment. These limitations mean the record does not support a causal conclusion or a quantitative estimate of the primary association.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: An Observational Study on the Natural Course of Chronic Pancreatitis — NCT04574297.
• Registry record last updated 2021-11-30; status last verified 2021-10.
• Results first posted 2021-11-30.
• 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

This record describes an observational study of the natural course of chronic pancreatitis, sponsored by Changhai Hospital, with enrollment of 798. The study start date is 2011-01-01, the primary completion date is 2020-05-31, and the status is active, not recruiting.

The primary endpoint is the number of participants developing pancreatic insufficiency over 10 years, categorized as diabetes and steatorrhea, diabetes only, or steatorrhea only. Death is listed as a secondary outcome. Four groups appear in adverse-event reporting, with group-specific counts at risk and deaths. Serious and other event counts are recorded as 0 in each group.

The registry record lists zero analyses and does not report primary endpoint results, effect estimates, confidence intervals, or statistical tests. It also does not report the definitions of the group labels, missing-data methods, or analysis populations. Interpretation is therefore limited to the study question, registered endpoint, and descriptive counts recorded in the registry.