Bringing Care to Patients: Patient-Centered Medical Home for Kidney Disease: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Bringing Care to Patients: Patient-Centered Medical Home for Kidney Disease (NCT02270515), a na na study. The primary outcome is Kidney Disease Quality of Life (KDQOL-36) Mean Scale Scores at Baseline, 6, 12 and 18 Months: Unadjusted.

2. Clinical Question

The central question is therefore about quality-of-life scores over time among participants exposed first to usual dialysis care and then to the expanded care model. The survey assesses general physical health, mental health, disease burden, disease symptoms, and disease effects. Its scales range from 0-100, with higher scores indicating better quality of life. Because there is no separate concurrent control group, changes over time cannot be attributed to the expanded care model alone. The record does not report a randomized or otherwise like-for-like comparison that would help separate intervention-related change from other influences.

3. Trial Design

The registry describes a completed, single-group study of a patient-centered medical home for kidney disease among people with ESRD. Enrollment was 175. The study began in 2013-11, and primary completion was recorded as 2016-08. The registry lists the study as completed. Its allocation is recorded as NA, its masking as NONE, and its model as SINGLE GROUP. These entries are consistent with the described sequence: participants were observed during an initial baseline period under usual dialysis care, after which the dialysis care team was expanded.

The expanded team included a primary care doctor, nurse coordinator, community health worker, and pharmacist. Outcomes were to be assessed at baseline and every 6 months after the PCMH-KD intervention commenced. The primary outcome listing specifies KDQOL-36 mean scale scores at baseline, 6, 12, and 18 months, with unadjusted results. The registry lists 3 outcome measures and 20 analyses. Those counts do not, by themselves, identify the full analysis plan, the specific statistical tests, or how any results were selected for reporting.

This design gives repeated observations from participants across the usual-care period and the intervention period. It is not a randomized trial with an independent control arm. Consequently, the two periods are not a like-for-like comparison: time, changes in participants’ circumstances, and other events could coincide with the intervention. The registry record does not report a protocol for controlling those influences or a statistical plan for doing so. It also does not report a sample-size justification, interim analyses, or a detailed account of the timing and duration of each participant’s exposure.

The registry identifies the intervention as a patient-centered medical home for kidney disease and the arm as PCMH-KD dialysis care. The description makes clear that participants initially received usual dialysis care before the team was expanded; it does not describe a separate group continuing usual care throughout follow-up. This distinction matters when interpreting changes in the repeated scores.

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.

Before assignment: Clinical data (six months prior to enrollment date) was collected from the electronic medical record for all participants to compare the "usual care" for enrolled patients with the care received during the PCMH-KD intervention.

Intervention Period 1: 0-6 Months

Reasons for not completing this period:

Intervention Period 2: 6-12 Months

Reasons for not completing this period:

Intervention Period 3: 12-18 Months

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: Overall number of participants analyzed are the number who completed the KDQOL at each visit. They differ slightly from the number of participants in the flow chart due to missing KDQOL data. Ns are slightly lower for some scale scores due to missing items (see below).

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 Kidney Disease Quality of Life (KDQOL-36) Mean Scale Scores at Baseline, 6, 12 and 18 Months: Unadjusted, measured over Baseline (0) to 18 months.

The primary endpoint is the mean score on the Kidney Disease Quality of Life-36 survey, or KDQOL-36, at baseline and at 6, 12, and 18 months. The registry describes the results as unadjusted means with standard deviations. The survey is a kidney-disease-specific quality-of-life instrument covering five domains: general physical health, mental health, disease burden, disease symptoms, and disease effects. Each domain scale can range from 0-100, and a higher score indicates better quality of life.

Quality of life is relevant to a care model because it captures participants’ reported experience across physical, mental, and disease-related aspects of living with kidney disease. The different domains should be considered separately: a mean for one domain does not stand in for the other domains, and a domain score does not represent every aspect of health or care. The registry record identifies the instrument and domains but does not report numerical mean scores, standard deviations, or the visit-specific participant counts in the outcome results described in the record.

A mean gives a measure of the group’s average score at a visit, while the standard deviation describes the spread of individual scores around that mean. Neither statistic alone indicates how much each individual participant changed. Repeated group means can describe how the observed group scores varied over time, but without a reported comparison group or adjusted analysis they do not establish why any change occurred. No threshold for a clinically important difference is reported in the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The primary outcome is a continuous measure: KDQOL-36 domain scores expressed in units on a scale. The registry lists a mean and standard deviation at each of four visits: baseline, 6, 12, and 18 months. General explanation: a mean describes the average observed score among the participants included in that visit’s analysis. The standard deviation describes how dispersed those observed scores are around the mean. The standard deviation is not a measure of how precisely the mean has been estimated; a confidence interval would address uncertainty in the mean estimate, but confidence intervals are not reported in the registry record.

What does an unadjusted mean describe?

An unadjusted mean is calculated without statistical adjustment for other variables. In general, this makes the summary straightforward to interpret as the average observed score in the analysis group at a visit. It does not account for differences in participant characteristics, changes in the mix of participants contributing data, or other factors that could relate to the outcome. The record labels the KDQOL-36 results unadjusted. It does not report adjusted estimates or identify covariates used in a model.

Repeated measures from one group have a particular structure: scores at different visits come from observations over time in the same study population, and observations from the same participant may be related. General explanation: an analysis that compares repeated measurements can account for this within-participant relationship, whereas treating every measurement as independent may misrepresent uncertainty. The registry outcome description does not state whether the analyses used a repeated-measures model, paired comparisons, or another method. That method is not reported in the registry record, so it should not be inferred from the fact that scores were collected over time.

How should change over time be understood?

Comparing means across visits describes differences between the observed group averages. General explanation: a causal estimate requires a design and analysis that make the intervention contrast credible, including consideration of what would have happened over the same period without the intervention. In a single-group before-and-after sequence, the intervention period is also later in calendar time. Without a concurrent comparison group, a change may reflect the intervention, time-related trends, other events, or a combination of influences. The registry record does not report an approach that separates these possibilities.

A confidence interval, in general, gives a range of values compatible with the data under the assumptions of the statistical method used. It conveys uncertainty around an estimate; it is not a guarantee that the true value lies in that range. The registry record does not report confidence intervals for the primary endpoint. It also does not report p-values or a formal test of change in the outcome description. No conclusion about statistical significance or the precision of a change can be drawn from the mean-and-standard-deviation description alone.

Why do missing observations matter?

The record says that the number analyzed for the quality-of-life outcome is based on the number completing the KDQOL at each visit. It also says those numbers differ slightly from the flow-chart count because of missing KDQOL data, and that some scale-score counts are slightly lower because of missing items. General explanation: when observations are missing, the analyzed participants at one visit may not be exactly the same set as those at another. If participants with missing scores differ systematically from participants with observed scores, the observed means may not represent the full enrolled group in the same way. The pattern and reasons for missingness, any imputation, and sensitivity analyses are not reported in the registry record.

Scale scores can also be missing because a participant completed some, but not all, items needed for a domain score. The record notes this issue but does not describe the scoring rules used when items were missing or the threshold for calculating each scale. Without those details, the exact handling of incomplete questionnaires cannot be assessed.

What does the listed analysis count establish?

The registry lists 3 outcome measures and 20 analyses. General explanation: multiple outcomes or analyses can involve multiple questions and comparisons, and the chance of at least one apparently unusual result can increase when many tests are considered. Researchers may address multiplicity by defining a primary comparison in advance or using an adjustment procedure. The record does not report whether any such approach was used, which comparisons were prespecified, or whether the 20 analyses include all planned or reported tests. The counts alone do not establish the statistical plan.

The study’s design is recorded as single group, with allocation listed as NA and masking as NONE. These details mean the posted design does not describe random assignment or masking. The registry record does not report a sample-size justification or a power calculation for the primary quality-of-life outcome. Any planning illustration based on an observed effect would not be a record of the trial’s original design justification and would not represent observed power. Specific numerical planning estimates are not reported in the registry record.

10. Multiplicity, Missing Data and Analysis Populations

The registry record lists 3 outcome measures and 20 analyses, but does not describe which outcomes or comparisons were designated as primary for statistical testing beyond identifying the KDQOL-36 mean scale scores as the primary outcome. It does not report a multiplicity adjustment, a hierarchy for testing outcomes, or whether the listed analyses reflect prespecified or exploratory questions. General explanation: when several outcomes or comparisons are examined, interpreting each result as though it were the only test can make chance findings more likely. Without a stated strategy, the extent to which multiplicity was addressed is not reported in the registry record.

Missing outcome data are directly noted. The number analyzed at each visit is based on the participants who completed the KDQOL survey, and those counts differ slightly from the flow-chart count because of missing KDQOL data. Counts are slightly lower for some scale scores because of missing items. The registry record does not report the visit-specific analysis counts in the outcome description, reasons for missingness, whether missingness differed across visits, or how incomplete scale items were handled.

General explanation: missingness can affect both precision and interpretation. If people with missing scores have different quality-of-life scores from those with observed scores, the observed mean may not reflect the full group. Methods such as imputation or sensitivity analyses can examine the consequences of missing data, but neither their use nor their assumptions are reported in the registry record.

The population analyzed is described as participants completing the questionnaire at each visit, rather than a single fixed analysis count across all visits. The registry record does not state whether analyses followed an intention-to-treat principle, how participants who discontinued or missed visits were handled, or whether any analysis population was defined in a protocol. Those details are not reported in the registry record.

11. Safety Results

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

Other (non-serious) adverse events

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

The safety entry lists the PCMH-KD dialysis care group with 175 participants at risk for serious adverse events and 0 affected. It also lists 175 at risk for other adverse events and 0 affected. These figures are registry entries for the reported group; they do not describe a comparison with a separate control group.

The record does not list any serious adverse event terms among the top serious terms. The deaths field is null, which is not the same as a reported count of zero deaths. The registry record therefore does not establish a death count from that field. It also does not report the safety observation window, event definitions, how events were collected, or whether events were assessed as related to the intervention.

General explanation: an adverse-event count is a summary of events recorded under the study’s reporting procedures. A zero in a posted count means no affected participants were entered in that category in the registry result; it does not, on its own, establish that no events occurred outside the reporting window or that all possible events were captured. The figures should be read as registry reporting, not as a comparison of safety between interventions.

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

The registry record establishes that this completed study enrolled 175 participants and evaluated a patient-centered medical home for kidney disease in a single-group sequence. Participants were initially observed under usual dialysis care, after which the team was expanded to include a primary care doctor, nurse coordinator, community health worker, and pharmacist. The primary outcome was KDQOL-36 mean scale scores at baseline, 6, 12, and 18 months, described as unadjusted means with standard deviations.

The record does not report the numerical primary outcome results. As a result, the direction and magnitude of score changes, the variability in observed scores, and the precision of any differences cannot be characterized from the outcome information in the registry record. The measure’s interpretation is stated: scores range from 0-100 and higher scores indicate better quality of life. That scoring direction does not supply the missing observed scores or determine whether any change was clinically important.

Even if a difference between visit means is available elsewhere, the design described in the registry does not support treating that difference alone as an effect caused by PCMH-KD. There is no separate concurrent control group in the record, and the intervention follows the baseline period. General explanation: in a before-and-after design, changes over time can be associated with the intervention period without demonstrating that the intervention caused them.

The posted safety entries report 0 affected participants for serious adverse events and 0 for other adverse events among 175 at risk in each category. The death field is null rather than a reported zero. These entries should be interpreted as registry reporting and do not provide a detailed account of event definitions, observation time, or ascertainment.

In short, the record describes the study structure, the measure, and the assessment schedule. It does not report the primary numerical results or enough statistical detail to judge the size, uncertainty, or cause of changes over time.

13. Why This Trial Matters Statistically

This study is statistically notable as an evaluation of a care model using repeated quality-of-life measurements in a single group. The baseline period followed by an expanded care team creates a useful description of how measured scores were intended to be tracked over time. It also illustrates why the design behind an outcome matters: repeated observations can show patterns, but a before-and-after sequence without a concurrent control group cannot by itself isolate the intervention’s contribution to those patterns.

The KDQOL-36 covers several distinct domains rather than reducing quality of life to a single general measure. Reporting domain means can help distinguish which aspects of participants’ reported experience are being measured. At the same time, each domain requires its own result and interpretation. A broad description of quality of life should not be substituted for the specific scores, their uncertainty, or the number of participants contributing data at each visit.

The record also notes that questionnaire completion and missing items affect analysis counts. This is a practical statistical issue for longitudinal studies: different observed samples at different visits can complicate comparisons of group averages. Transparent reporting of visit-specific counts, missing-data handling, and uncertainty would help readers judge how robust those comparisons are.

Finally, the registry lists multiple outcome measures and analyses but does not report the associated multiplicity strategy or detailed analysis plan. This makes the distinction between descriptive monitoring and confirmatory testing important. The study record supplies meaningful design context, but the primary numerical results and key analysis details are not reported in the registry record. That limits the statistical conclusions that can be drawn from the record.

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 interpretation is that the registry describes a single-group before-and-after design. Participants were observed under usual dialysis care first and then received the expanded PCMH-KD team. There is no separate concurrent control group in the record, so temporal changes cannot be separated from intervention-associated changes using the design description alone. The registry does not report an adjustment strategy intended to address this limitation.

The primary outcome results themselves are not reported in the registry record. Although the endpoint, scale range, direction of scoring, and assessment visits are described, no visit-specific means, standard deviations, or analysis counts are given in the outcome information. Therefore, the observed pattern and its precision cannot be assessed.

Outcome completion varied by visit, and some scale scores had lower counts because of missing items. The record does not report reasons for missing surveys or items, how incomplete scales were scored, whether missingness was related to participant characteristics or outcomes, or whether sensitivity analyses were performed. This leaves uncertainty about the representativeness of the observed scores at each visit.

The registry lists 20 analyses but does not describe the statistical methods, prespecified comparisons, multiplicity handling, or analysis populations. A sample-size justification, interim analyses, and detailed protocol information are not reported in the registry record. Safety reporting is also limited: the record does not specify event definitions, ascertainment, or the observation window, and its deaths field is null rather than a reported count.

These limitations concern what can be concluded from the registry record; they do not establish that unreported procedures were or were not performed. The record’s completed status and enrollment figure do not resolve the absent outcome and analysis details.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Bringing Care to Patients: Patient-Centered Medical Home for Kidney Disease — NCT02270515.
• Registry record last updated 2017-04-07; status last verified 2017-03.
• Results first posted 2017-03-01.
• 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

The registry record describes NCT02270515, a completed, single-group study of a patient-centered medical home for kidney disease among people with ESRD. Enrollment was 175. The study began in 2013-11, with primary completion recorded in 2016-08. Participants received usual dialysis care during an initial baseline period, followed by an expanded team that included a primary care doctor, nurse coordinator, community health worker, and pharmacist.

The primary outcome was unadjusted mean KDQOL-36 scale scores at baseline, 6, 12, and 18 months. The instrument assesses five quality-of-life domains, with scores from 0-100 and higher scores indicating better quality of life. The registry record does not report numerical results for these scores or the detailed statistical analysis plan. It notes missing survey data and missing items that affected analysis counts.

The safety entry reports 0 participants affected by serious adverse events and 0 affected by other adverse events among 175 at risk in each category. The deaths field is null. The single-group design does not provide a concurrent control comparison.