Quality Improvement of Patient-Provider Communication For Colorectal Cancer Screening: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Quality Improvement of Patient-Provider Communication For Colorectal Cancer Screening (NCT00324753), a randomized na study. The primary outcome is Completion of Colorectal Cancer Screening Tests.

2. Clinical Question

The study’s stated immediate objective was to assess whether a multifaceted communication intervention could improve adherence to colorectal cancer screening recommendations. The proposed mechanism was not a change to the screening tests themselves, but a change in the interaction between patients and providers: helping patients initiate a discussion, organizing the information raised, and prompting providers to check how patients perceived the conversation.

The clinical question therefore concerns both communication and subsequent screening behavior. The registry describes survey questions about whether screening was discussed during the visit and patient satisfaction with provider communication, alongside record-based assessment of test ordering and completion. These measures describe different parts of the proposed pathway; a discussion or favorable communication rating is not the same outcome as a completed screening test.

The record identifies completion of screening tests as the primary outcome, but its description includes several tests and the recorded timeframe is not presented consistently: the outcome timeframe is listed as 6-12 months, while the description refers to the study period as 6 months from the clinical encounter. A clear, single outcome definition and a corresponding comparison are not reported in the registry record.

3. Trial Design

The study is identified as a randomized, single-masked, parallel-group trial. Its registry status is completed, with enrollment listed as 454. The study is associated with colorectal cancer and sponsored by the VA Office of Research and Development. The listed phase is NA, which is not a clinical drug-development phase designation.

Participants were assigned to a communication intervention or a control condition. The intervention arm is described as receiving a communication sheet; the control arm is described as receiving standard-of-care brochures. The study summary adds that the intended intervention included patient activation to initiate a colorectal cancer screening discussion, a prompt sheet to optimize discussion content, and a cue for providers to assess patient perceptions of the communication. The record does not describe the precise delivery procedures or explain how the single masking designation was implemented.

The record gives a start date of 2007-04 and a primary completion date of 2010-06. It describes a survey covering patient characteristics, family history, provider recommendations, screening discussions, and satisfaction with communication. Medical record review was used to collect information on provider ordering and patient completion of fecal occult blood testing, sigmoidoscopy, or colonoscopy.

The primary outcome timeframe is listed as 6-12 months. However, the outcome description says that the study period was 6 months from the clinical encounter. The record does not explain the difference between these timeframe descriptions. Nor does it give enough detail to determine whether the listed completion outcome was analyzed separately for each test, combined across tests, or assessed at multiple time points.

The registry lists 3 outcome measures and 1 analysis. The primary outcome has several categories or time points and is not reduced in the registry record to a single comparison. The record does not report the randomization sequence, allocation concealment, masking procedures, sample-size justification, or detailed statistical analysis plan.

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 Completion of Colorectal Cancer Screening Tests, measured over 6-12 months.

The primary outcome is titled “Completion of Colorectal Cancer Screening Tests” and is measured in participants. The registry classifies it as a count of participants with an event. In practical terms, the event is completion of a colorectal cancer screening test, with the description naming fecal occult blood testing, sigmoidoscopy, and colonoscopy. Medical record review was used to collect information about test ordering and completion during the study period.

This outcome is relevant to the study’s stated objective because it assesses screening behavior, rather than communication alone. The surveys addressed whether screening was discussed and how patients rated communication; the record review addressed ordering and completion. Those measures capture distinct stages and should not be treated as interchangeable. A screening discussion, a provider order, and a completed test represent different observations.

The outcome timeframe requires care in interpretation. The registry’s timeframe field says 6-12 months, whereas its description says the study period was 6 months from the clinical encounter. The record does not clarify how those statements relate to each other, or whether they refer to different parts of the outcome assessment.

Although the outcome is described using participant counts, the posted registry information does not provide a single set of event counts or a single intervention-versus-control estimate for test completion. It notes that the primary outcome has several categories or time points and was not reduced to one comparison. The outcome’s exact aggregation rule, event definition across the named tests, and analysis time point are not reported in the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry describes a randomized, parallel-group study. Randomization is a method for assigning participants to study conditions by chance, with the aim of making the groups comparable on average at the start of a trial. It does not ensure that every characteristic will be balanced in a particular study, and it does not remove the need to report the allocation process and the analyzed groups. Details of sequence generation and allocation concealment are not reported in the registry record.

The parallel design means the intervention and control conditions were compared across groups rather than through a planned sequence of treatments within each participant. The recorded conditions were a communication intervention, represented by a communication sheet, and standard-of-care brochures. The study is listed as single-masked. General explanation: masking is intended to limit the influence of knowledge about treatment assignment on aspects of study conduct or assessment. The record does not identify who was masked or how masking was maintained, so the practical protections cannot be assessed.

What does a participant count represent?

The primary endpoint is described as a count of participants with an event. For an outcome such as screening-test completion, an event count records the participants meeting the stated completion definition. A group count alone is not enough to compare groups: interpretation also requires the relevant denominator, a clear event definition, and a specified time period. The registry does not report the primary endpoint counts or a single comparison for the listed tests and time points.

General explanation: a binary outcome distinguishes whether an event occurred for each participant under a defined rule. Analysts may report the proportion with the event, a difference in proportions, a relative measure, or another contrast. These are different ways of expressing a comparison, and their interpretation depends on the outcome definition and analysis. No such primary-outcome contrast is reported in the registry record, so no effect measure should be inferred.

Why do the outcome definition and timeframe matter?

The outcome description names fecal occult blood testing, sigmoidoscopy, and colonoscopy. A combined endpoint would require a rule defining how completion of these tests is counted, while separate endpoints would produce test-specific comparisons. The registry does not say which approach generated the primary comparison. It also lists a timeframe of 6-12 months but describes the medical-record study period as 6 months from the clinical encounter. Because timing determines which records and events qualify, that discrepancy cannot be resolved by statistical interpretation alone.

General explanation: a confidence interval communicates uncertainty around an estimated effect, conditional on the analysis and its assumptions. Its width is affected by features such as the amount of information available and the variability of the outcome. A narrow interval is generally more precise than a wide one, but precision does not establish clinical importance or remove possible bias. The registry record does not report a primary effect estimate or interval for screening completion.

What can be learned from a p-value?

General explanation: a p-value measures how unusual data at least as incompatible with a specified null hypothesis would be under that hypothesis and the statistical model. It is not the probability that the null hypothesis is true, and it does not indicate the size or practical importance of an effect. A p-value is interpretable only in the context of the chosen outcome, comparison, and analysis. No primary-outcome p-value is reported in the registry record.

The record lists 3 outcome measures and 1 analysis, but does not explain the analysis method or whether it addressed all listed outcomes. It does not report whether the analysis adjusted for baseline characteristics, how repeated or multiple endpoint observations were handled, or whether the primary analysis followed randomized assignment. The particular statistical test, model, and uncertainty method are not reported in the registry record.

The sample-size assumptions describe a planning illustration rather than the original trial’s design justification. That illustration is described as using a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation, with the effect to detect expressed as a fraction of the observed effect. Such assumptions are planning choices; any resulting sample-size estimate is not an observed study outcome and is not “observed power.” The registry does not report the protocol’s sample-size justification. It also does not provide enough detail to evaluate any planning illustration against the original design.

General explanation: when outcomes are examined across multiple tests or time points, the chance of obtaining a seemingly notable result can depend on how many comparisons were considered and how they were selected. Multiplicity methods can address that issue, but their appropriateness depends on the prespecified analysis plan. The registry does not report whether the primary outcome’s categories or time points were prespecified, how they were analyzed, or whether any multiplicity adjustment was used.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists 3 outcome measures and 1 analysis, but does not describe the relationship between the outcomes and the analysis. In particular, the primary outcome is noted as having several categories or time points and is not reduced to a single comparison. The record does not specify which test types or time points were treated as primary, whether they were analyzed separately or combined, or how any choice among results was made.

General explanation: examining multiple outcomes or time points can increase the opportunity for apparently notable findings, especially when the analysis or reporting choice is influenced by the observed results. A prespecified analysis plan and transparent reporting help readers understand which comparisons were intended and whether adjustments for multiple comparisons were made. Whether such an adjustment is needed depends on the study question and analysis plan; the registry does not report a multiplicity strategy.

Missing-data handling is also not reported in the registry record. The record does not state how participants with unavailable survey responses or medical records were handled, whether missingness was assessed, or whether any imputation or sensitivity analysis was used. It does not report the number of participants contributing to the primary outcome analysis.

The analysis population is not specified. The registry does not say whether participants were analyzed according to randomized assignment, whether exclusions occurred after assignment, or whether the analysis used another population definition. Enrollment is listed as 454, but that figure alone does not identify the number included in any particular outcome analysis. Without an analysis population, outcome-specific denominators, and missing-data procedures, readers cannot assess how complete the endpoint data were or how the analytic sample relates to the randomized groups.

11. 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 registry records 0 serious adverse events among 190 participants at risk in the intervention group, and 0 among 264 participants at risk in the control group. The death count is 1 in the intervention group and 1 in the control group. These are the recorded counts, not rates, and no rate calculation or comparative safety estimate is reported in the registry record.

Serious adverse events and deaths are separate entries in the registry’s safety information. The record does not explain whether either death met the serious-adverse-event definition, when the deaths occurred, their causes, or whether investigators considered them related to the intervention. The counts therefore should not be combined or used to infer a causal relationship.

General explanation: a count of 0 recorded events does not demonstrate that an event is impossible, nor does it establish that two groups have equivalent safety. The strength of a safety comparison depends on the amount of follow-up, event definitions, completeness of reporting, and an analysis that accounts for the groups being compared. Those details are not reported in the registry record. The listed at-risk counts are useful context, but they do not by themselves establish the duration or completeness of safety surveillance.

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

The study addresses a practical research question: whether a structured approach to patient-provider communication can be associated with completion of colorectal cancer screening tests. Its intervention was designed to support the conversation around screening, while the control condition used standard-of-care brochures. The registry describes surveys about communication and medical record review of test ordering and completion, giving the study a focus that extends beyond patient satisfaction alone.

What the record does not establish is the direction or size of any effect on test completion. The primary outcome is not presented as a single comparison, and no event counts, effect estimate, confidence interval, or p-value for that endpoint are reported. It is therefore not possible from the registry record to determine whether screening completion differed between arms, or how precisely any difference was estimated. This is not evidence that the intervention did or did not change screening behavior.

The registry also does not support a conclusion about whether communication changed. Although the study description identifies questions about screening discussions and satisfaction with provider communication, it does not give the corresponding results. Nor does it report whether providers ordered tests differently. These intermediate measures may help explain a proposed pathway, but their results cannot be inferred from the study’s objectives.

General explanation: a trial’s intended mechanism and its measured endpoint are related but distinct. An intervention can be designed to influence communication, yet a claim about screening completion requires results for that endpoint. Likewise, observing a difference in communication would not automatically establish a difference in completed tests. Each claim needs an explicitly defined measure and a reported analysis.

The record’s safety entries report no serious adverse events in either group and 1 death in each group. They do not explain event context or provide a comparative safety analysis. These figures should be read as registry counts, not as proof of no risk or proof that the groups had the same safety experience.

Overall, the registry supports a description of the study question and design, but not a conclusion about effectiveness, lack of effect, or clinical importance. The outcome timeframe is also described in two ways, and the record does not explain how those descriptions align. A fuller report would need to define the endpoint, clarify timing, give group-specific outcome results, identify the analysis population, and quantify uncertainty.

13. Why This Trial Matters Statistically

This trial is statistically interesting because its intervention targets communication, while its primary outcome concerns completed screening tests. That distinction makes outcome definition important. Communication discussions, patient satisfaction, provider orders, and completed tests answer different questions; a clear analysis must say which of these is the primary endpoint and how it relates to the others.

The registry’s primary-outcome description includes several screening tests and a timeframe that is not internally clear: the listed timeframe is 6-12 months, while the description refers to a study period of 6 months from the encounter. The record also notes that the outcome has several categories or time points and was not reduced to a single comparison. Together, these features show why results need transparent definitions and an explicit analysis plan. Without them, readers cannot tell what contrast a reported result would represent.

General statistical explanation: a randomized design can help support a causal comparison when assignment, follow-up, outcome measurement, and analysis are adequately implemented and reported. Randomization alone does not tell readers whether the groups remained comparable in the analyzed data, whether outcomes were missing, or whether the chosen comparison was prespecified. Reporting those details is essential for judging the strength and limits of the evidence.

The record’s safety entries also illustrate the difference between counts and comparative inference. Serious adverse-event counts and death counts are useful descriptive information, but they do not by themselves quantify a difference in safety or establish why events occurred. Interpretation requires context about definitions, follow-up, and the analysis.

Finally, the record lists 3 outcome measures and 1 analysis but does not provide the detailed statistical plan or a single primary-outcome result. This makes the trial a useful example of how registry information can describe a study’s aims and structure without supplying enough results to evaluate its main effect. Transparent endpoint definitions, denominators, analysis populations, missing-data procedures, and uncertainty estimates are needed for a fuller statistical assessment.

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 trial-specific limitation for interpretation is that the registry does not report a single primary-outcome comparison. It identifies completion of colorectal cancer screening tests as the primary outcome, but notes that the outcome contains several categories or time points and is not reduced to one comparison. No group-specific completion counts, effect estimate, confidence interval, or p-value for that outcome are reported in the registry record.

The outcome timeframe is ambiguous in the record: the timeframe field lists 6-12 months, while the description refers to a study period of 6 months from the clinical encounter. The record does not explain whether these descriptions refer to different assessments or how the primary endpoint was timed. It also does not specify how completion across fecal occult blood testing, sigmoidoscopy, and colonoscopy was combined or distinguished.

Further limitations arise from missing methodological detail. The randomization sequence and allocation concealment are not reported. The record identifies single masking but does not say who was masked or how. It does not report a detailed statistical analysis plan, analysis population, outcome-specific denominators, missing-data procedures, or whether the analysis followed randomized assignment.

The registry lists 3 outcome measures and 1 analysis, but does not report how the analysis addressed the multiple outcome categories or time points, or whether multiplicity was considered. It does not give the results for communication discussions, satisfaction, or provider ordering. Consequently, the record cannot support interpretation of these related outcomes either.

Safety reporting is limited to counts of serious adverse events and deaths. Event timing, definitions, causes, relatedness, and the duration and completeness of safety follow-up are not reported in the registry record. These limitations concern what can be assessed from the registry information; they do not establish that the study did not collect additional information.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Quality Improvement of Patient-Provider Communication For Colorectal Cancer Screening — NCT00324753.
• Registry record last updated 2018-11-29; status last verified 2018-11.
• Results first posted 2018-11-29.
• 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.

18. Record Summary

NCT00324753 is a completed, randomized, single-masked, parallel-group study sponsored by the VA Office of Research and Development. The record lists enrollment as 454 and identifies colorectal cancer as the condition. The study dates are recorded as 2007-04 for start and 2010-06 for primary completion.

The intervention was a communication approach, with a communication sheet named in the arm description; the control condition was standard-of-care brochures. The study aimed to improve patient-provider communication about colorectal cancer screening and assessed completion of screening tests through medical record review. The primary outcome names fecal occult blood testing, sigmoidoscopy, and colonoscopy.

The registry lists 3 outcome measures and 1 analysis, but notes that the primary outcome has several categories or time points and is not reduced to a single comparison. A primary-outcome effect estimate and its uncertainty are not reported in the registry record. The timeframe is listed as 6-12 months, while the description refers to 6 months from the clinical encounter. Safety entries list 0 serious adverse events in each group and 1 death in each group, without further event context.