Evaluation of Long-term Effect of Resonator Therapy on Parkinson's Disease (PD): Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Evaluation of Long-term Effect of Resonator Therapy on Parkinson's Disease (PD) (NCT00862537), a registered phase not stated study. The primary outcome is Change in Parkinson's Disease Questionnaire-39 Single Index Score (PDQ-39SI)From Baseline to Study Endpoint of 11 Months.

2. Clinical Question

The clinical question concerns change in Parkinson’s disease-related quality of life during an extension study of Resonator magnetic field therapy. The registry record describes an open-label study of people who had previously participated in Pilot I or Pilot II studies. It lists one active therapy group and does not describe a like-for-like control comparison. The primary outcome was change in the PDQ-39 Single Index score from baseline to the study endpoint of 11 months.

This framing is descriptive rather than a causal comparison. A change between baseline and follow-up can reflect events during the study period, but without a documented concurrent control group it cannot isolate the effect of the device from other explanations. The record also does not report whether all enrolled participants contributed endpoint data.

3. Trial Design

This was an open-label extension study for subjects previously treated in Pilot I or Pilot II studies of the application of magnetic fields using the Resonator. The registry record describes low level magnetic fields intended to treat some symptoms of idiopathic Parkinson’s disease. The listed intervention is the Resonator Device, and the arm description specifies administration of active magnetic fields with that device.

The registry lists enrollment of 18 and a status of completed. The recorded study start is 2008-04, and primary completion is recorded as 2011-04. These dates describe the study record and do not establish when each participant began or completed follow-up. The primary endpoint timeframe is baseline and 11 months.

The record does not describe a randomized comparison. Allocation is not stated, and the listed arm information does not establish a concurrent control group. The extension design therefore does not support a direct treatment-versus-control estimate from the registry information. Prior participation in earlier studies is part of the eligibility context, but the record does not provide the earlier studies’ treatment histories or individual-level results.

Open-label means the study is not described as masking participants or study personnel to the intervention. The registry does not report masking procedures, whether outcome assessment was independent, or how participant expectations were addressed. These design details matter particularly for a patient-reported quality-of-life measure. The record lists one outcome measure and no analyses. It does not report the protocol, recruitment flow, withdrawals, adherence, or a detailed statistical 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 Change in Parkinson's Disease Questionnaire-39 Single Index Score (PDQ-39SI)From Baseline to Study Endpoint of 11 Months, measured over baseline and 11 months.

The primary endpoint is change in the Parkinson’s Disease Questionnaire-39 Single Index score (PDQ-39SI) from baseline to the study endpoint of 11 months. The PDQ-39 is a 39-item quality-of-life questionnaire for people with Parkinson’s disease. The description says it evaluates eight dimensions: mobility, activities of daily living, emotional well-being, stigma, social support, cognition, and communication. The record says eight dimensions, although its written list names fewer than eight.

The Single Index score is described as a weighted addition of scores across the dimensions. It ranges from 0, indicating no disease impact, to 100, indicating severe disease impact. As a patient-reported measure, it captures perceived effects on daily life and well-being rather than a direct measurement of a biological process. A change score compares the participant’s score at follow-up with their baseline score, making the endpoint relevant to change over time.

The registry specifies the mean and standard deviation as the summary approach, with scores measured on a scale. It does not report a mean change, standard deviation, participant-level observations, or a confidence interval. The outcome’s use in the study does not by itself show whether scores improved, worsened, or stayed similar; those numerical results are not reported in the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry identifies the primary outcome as a continuous score summarized by a mean and standard deviation. These are different kinds of summaries. The mean describes the average score or average change across participants, while the standard deviation describes how spread out participant values are around that average. Neither summary is reported numerically for the primary outcome in the registry record.

What does a change score represent?

For a baseline-to-follow-up endpoint, an individual change score is formed by comparing that person’s follow-up score with their baseline score. The group mean change then summarizes those individual changes. This approach can account for the fact that each person has their own starting score. It does not, by itself, remove changes due to time, other care, natural variation, or expectations. Those are general properties of within-person before-and-after comparisons.

The record names baseline and 11 months as the measurement time points. It does not report the actual paired observations, the number with scores at both time points, or the mean and standard deviation of the change. It also does not say how partially completed questionnaires were scored. These omissions prevent an independent evaluation of how the endpoint was calculated.

How should variability and precision be understood?

In general, the standard deviation describes variation among participants, not the precision of the estimated group mean. Precision is commonly conveyed with a confidence interval around an estimate. A confidence interval gives a range of values compatible with the data under the method used, and its width depends on factors such as sample size and variation. No confidence interval for the PDQ-39SI result is reported in the registry record, so its precision cannot be assessed.

A small standard deviation would indicate that participants’ values were relatively similar to one another, while a large standard deviation would indicate more spread. Neither pattern alone determines whether an estimated average change is precise or clinically important. In general, the standard error of an estimate relates variation to the amount of information available, but the necessary outcome data and analysis details are not reported.

What does an unadjusted recalculation mean?

In general, a recalculation from posted summary statistics is a simple, unadjusted calculation based on the values that are available. It is not a substitute for the sponsor’s own analysis when a discrepancy is present, and it may not reproduce an analysis that accounts for design features or participant-level data. No outcome summary statistics or recalculated primary result are reported in the registry record for this study. There is therefore no recalculated estimate to interpret.

What can a planning calculation show?

Sample-size illustrations are planning exercises, not observed trial results and not observed power. The stated assumptions for a planning illustration are a two-sided significance level of 0.05, equal allocation between two arms, a normal approximation, and an effect defined as a stated fraction of the observed effect. For continuous outcomes, the illustration expresses the needed number of participants per arm. These assumptions describe a hypothetical design calculation; they do not establish that this extension used that design or that a comparison between two arms occurred.

The documented study lists active Resonator therapy and does not describe a like-for-like control group. A two-arm planning assumption therefore should not be mistaken for the actual structure of this extension. The observed effect required as the basis for such an illustration is not numerically reported in the registry record, and there is no reported primary outcome analysis from which to evaluate it.

Why do design and analysis details matter?

In general, random allocation can make treatment groups more comparable at the start of a study, while masking can reduce the influence of treatment awareness on care and assessment. Neither feature is documented as part of a randomized comparison in this record. A paired analysis of baseline and follow-up scores would address within-person measurements, but the record does not specify the statistical test or model used. It also does not report adjustment for other factors, handling of outliers, assumptions checks, or sensitivity analyses.

Over-dispersion is a concept most relevant to count outcomes: it means the observed spread exceeds what a simple count model assumes and can lead to overly narrow uncertainty estimates if ignored. The primary endpoint is described as a continuous score, not a count outcome, and no over-dispersion assessment is reported. More generally, the statistical method must match the outcome type and the study design; the registry’s limited analysis information does not permit a full appraisal.

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("Active Resontaor Device Therapy")
n   <- c(18)
m   <- c(4.96)
sp  <- c(1.1)
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  Active Resontaor Device Therapy  18  4.960  1.100  4.413  5.507

11. Multiplicity, Missing Data and Analysis Populations

The registry lists one outcome measure and no analyses. That record does not report how many statistical tests were planned or conducted, whether other outcomes were assessed outside the listed entry, or whether the primary endpoint was selected before results were examined. The statistical plan is not reported in the registry record.

Multiplicity arises when several outcomes, time points, subgroups, or statistical tests are examined. In general, the more analyses considered, the greater the chance that at least one result may appear notable by chance if no adjustment or prespecified hierarchy is used. Whether that issue applies and how it was handled in this study are not reported. A single listed outcome does not establish that only one analysis was performed.

The record does not state how missing questionnaire responses or missed follow-up visits were handled. It does not report imputation, complete-case analysis, a sensitivity analysis, or reasons for missingness. Nor does it define an analysis population, such as all enrolled participants or only participants with endpoint data. These details affect the interpretation of a mean change because the participants represented in that mean may differ from the full enrolled group.

Without participant flow and endpoint completion information, the relationship between enrollment of 18 and the number analyzed cannot be determined. The registry record also does not report whether the primary endpoint analysis included only complete questionnaires or allowed partial scores. No assumptions about missing data or analysis populations can therefore be attributed to this study from the available record.

12. 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 5% reporting threshold.

The registry lists an active Resonator device therapy group with 18 participants at risk for serious adverse events and zero affected. It also lists 18 at risk for other adverse events and zero affected. These are the posted counts for the recorded group; they are not estimates of risk in a comparator group, because no like-for-like control group is described.

A count of zero affected means that the registry entry records no affected participants for the specified category. It does not prove that an event is impossible or that the intervention is free from risk. General interpretation of safety counts depends on the number observed, the duration and completeness of follow-up, and how events were collected and classified. The registry does not provide detailed event definitions, monitoring procedures, or a list of serious event terms.

Deaths are not reported in the registry record. The absence of serious adverse event terms in the entry should not be read as a complete account of all possible safety outcomes. The record also does not provide event-level narratives or information about whether events were judged related to the device. The posted counts are therefore descriptive and limited to the categories and information entered in the registry.

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

The record establishes that an open-label extension study evaluated active Resonator magnetic field therapy in people with Parkinson’s disease who had participated in earlier pilot studies. It also identifies a patient-reported quality-of-life endpoint: change in PDQ-39SI from baseline to 11 months. These details clarify the intended question and the outcome selected to address it.

The registry entry does not report a numerical result for that endpoint. It therefore cannot show whether scores changed, in which direction they changed, how large any change was, or how precise an estimate might be. No conclusion about the effect of the intervention on PDQ-39SI can be drawn from an endpoint title alone.

Even with a numerical before-and-after result, an uncontrolled extension would not establish that the intervention caused the observed change. In general, a concurrent comparison group helps distinguish treatment effects from other changes over time. The registry does not describe such a comparator. The open-label design also means that participant and assessor awareness may be relevant when interpreting a self-reported outcome, although the record does not establish that awareness altered responses.

The safety entry records zero participants affected by serious adverse events among 18 at risk, and zero affected by other adverse events among 18 at risk. Those counts are limited to the registry entry and do not establish that no unrecorded events occurred or that risk is absent. Deaths are not reported in the registry record.

Thus, the record is useful for understanding the extension design, intervention, planned quality-of-life measure, and recorded adverse-event counts. It does not provide the outcome analysis needed to assess the observed change or its uncertainty, and it does not support a causal treatment comparison.

14. Why This Trial Matters Statistically

This trial is statistically notable because its clinical question is framed around change within participants rather than a documented comparison between independently assigned groups. Baseline and follow-up measurements can describe how scores evolve among participants, but a change over time is not the same quantity as a treatment effect against a control. That distinction is central when interpreting extensions of earlier studies.

The endpoint is a patient-reported quality-of-life score. Such outcomes can capture aspects of disease impact that are meaningful to participants, while also being sensitive to expectations and how questions are understood. In an open-label study, these measurement considerations deserve attention. The registry record does not report the steps used to address them.

The entry also illustrates why outcome definitions and outcome results must be distinguished. The PDQ-39SI scale and its timeframe are described, but no numerical change or uncertainty estimate is posted. Without those values, statistical significance, precision, and practical importance cannot be evaluated. The registry lists enrollment of 18, but the number with usable endpoint data is not reported.

Finally, a sample-size planning illustration is not evidence of statistical power achieved in the study. The stated illustration assumptions use two arms, while the listed study information describes active therapy without a like-for-like comparator. Treating planning assumptions as a description of the actual study would confuse design calculations with observed evidence. These distinctions help keep descriptive registry information separate from claims that require outcome results and an appropriate comparison.

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.

The primary limitation for interpretation is that the registry record does not report the numerical PDQ-39SI change, its standard deviation, a confidence interval, or a statistical test. The stated primary outcome can be identified, but its observed result and precision cannot be assessed. The record lists no analyses.

The extension is described as open-label and does not provide a like-for-like control comparison. This limits causal interpretation of any change between baseline and 11 months. The record does not state allocation, masking procedures, or whether outcome assessment was independent. It also does not provide enough information to judge the influence of expectations on the patient-reported endpoint.

Enrollment is listed as 18, but the registry does not report participant flow, endpoint completion, withdrawals, adherence, or the number included in an outcome analysis. Missing-data handling and the analysis population are not reported. Consequently, the representativeness of any potential endpoint estimate cannot be assessed.

The study is an extension involving participants from prior pilot studies. The registry does not describe the earlier studies’ results or treatment histories in sufficient detail to assess how prior participation may relate to the extension findings. Other participant characteristics, eligibility details, outcome collection procedures, and a full statistical plan are not reported in the registry record. Safety counts are also limited: serious and other adverse event counts are listed, but deaths and detailed event terms are not reported.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Evaluation of Long-term Effect of Resonator Therapy on Parkinson's Disease (PD) — NCT00862537.
• Registry record last updated 2011-07-08; status last verified 2011-06.
• Results first posted 2011-07-08.
• 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

The registry record describes a completed open-label extension study titled Evaluation of Long-term Effect of Resonator Therapy on Parkinson’s Disease. It concerns people with Parkinson’s disease who previously participated in Pilot I or Pilot II studies. The listed intervention is active magnetic field therapy with the Resonator Device, and enrollment is 18. The recorded study start is 2008-04 and primary completion is 2011-04.

The primary endpoint is change in PDQ-39 Single Index score from baseline to 11 months. The record specifies a mean and standard deviation but does not report numerical outcome results or analyses. It does not describe a like-for-like control group. The adverse-event entry lists 18 at risk and zero affected for serious events, and 18 at risk and zero affected for other events. Deaths are not reported in the registry record.