Somatosensory Profiling in Radicular Pain Patients And it's Correlation With Treatment Outcome: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Somatosensory Profiling in Radicular Pain Patients And it's Correlation With Treatment Outcome (NCT02130258), a non-randomized na study. The primary outcome is Pre-epidural Warm Sensation Quantitative Sensory Testing (QST) Results.

2. Clinical Question

The investigators’ hypothesis was that quantitative sensory profiles might differ between participants who respond and those who do not respond to standard ESI therapy. The primary measure focuses on a warm-sensation threshold: a thermode is placed on the arm and then on the leg with radicular pain, and the temperature at which the participant first perceives warmth is recorded. The difference between the arm and leg temperatures is analyzed.

This is a question about whether a sensory measure recorded before treatment is associated with later pain-relief grouping. It is not a randomized test of ESI, and the groups do not establish that a difference in sensory testing caused a difference in pain relief. The registry record does not report how pain relief was assessed, when post-injection relief was categorized, or whether the primary question was adjusted for other participant characteristics.

3. Trial Design

The registry record describes a completed, non-randomized, parallel-group study sponsored by Massachusetts General Hospital. Enrollment was 23. The phase is listed as NA, and masking is listed as none. The study concerns radiculopathy and lower extremity radicular pain.

Participants were scheduled to receive an epidural steroid injection as treatment. Their clinical physician conducted the injection, and it was not part of the research procedures. Quantitative Sensory Testing was the research assessment and was conducted before the injection. The recorded primary endpoint is the difference between warm-sensation temperatures measured on the arm and the leg with radicular pain.

The groups are labeled >30% Pain Relief and <30% Pain Relief. Because allocation was non-randomized, these labels describe outcome-based groups rather than assigned interventions. The study therefore asks whether a pre-treatment sensory measure varies by subsequent pain-relief category; it does not provide a randomized comparison of injection against no injection or another treatment. The registry record does not describe the method used to assign participants to these categories, and the two labels do not specify how a participant with exactly 30% pain relief would be categorized.

The registry record lists a start date of 2012-05 and primary completion in 2016-12, with status completed. It lists three outcome measures and three analyses, but the details of the other outcome measures and how analyses correspond to outcomes are not reported in the registry record. The sample-size justification, recruitment approach, and any protocol deviations are also not reported in the registry record.

The registry record’s arm descriptions are incomplete: they state that QST would be conducted before treatment but do not provide the remainder of the description. Further procedural details, including any post-injection assessment schedule, are not reported in the registry record.

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: 23 subjects were initially enrolled. 3 subjects were withdrawn before assignment to groups for the following reasons: 1. sensory deficits at the site of QST and inability to complete questionnaires on own 2. did not receive ESI which is a requirement for the study

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 Pre-epidural Warm Sensation Quantitative Sensory Testing (QST) Results, measured over Baseline measurement before the epidural injection.

The primary endpoint is the pre-epidural warm-sensation QST result, expressed as the difference between the temperature recorded at the arm and the temperature recorded at the leg with radicular pain. The registry record specifies degrees Celsius and reports the outcome parameter as a mean with standard deviation. The measurement is taken before the epidural injection.

For the test, a small metal plate called a thermode is placed on the participant’s arm. Its temperature rises gradually, and the participant stops the test when the plate feels warm. The procedure is repeated on the painful leg. The temperature at the point when warmth is perceived can range from 32-53 degrees Celsius. The arm-leg temperature difference is the quantity analyzed, rather than either temperature alone.

As a sensory measure, this endpoint offers a way to describe variation in thermal perception across two body sites in a participant with radicular pain. Comparing the pre-injection measure across later pain-relief groups addresses the investigators’ hypothesis about sensory profiles and treatment outcome. The registry record does not report the group means, standard deviations, or the estimated difference between groups. It also does not explain why the arm-leg difference was selected over other QST measurements or provide a threshold for interpreting a difference as clinically meaningful.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry record describes a continuous primary outcome summarized by a mean and standard deviation. The measured quantity is the difference between warm-sensation temperatures at the arm and the painful leg. The record does not report the underlying observations, group summaries, or a statistical test of the difference between pain-relief groups. It also does not report a model or adjustment strategy.

What a mean describes

General statistical explanation: a mean is a measure of the center of a set of numeric observations. In this study, it would describe the average arm-leg temperature difference for a defined group of participants, if calculated from their recorded measurements. A group mean alone does not show how varied the individual measurements were, how many observations contributed, or whether a small number of unusual observations influenced the average. Those details matter when interpreting a continuous endpoint.

What a standard deviation describes

General statistical explanation: a standard deviation describes how dispersed observations are around their mean. A larger standard deviation indicates more variability in the measurements, while a smaller one indicates that observations are more concentrated around the mean. A standard deviation is not the same as a confidence interval: it describes variation among observations, whereas a confidence interval describes uncertainty about an estimated quantity. The registry record names standard deviation as the dispersion measure but does not report a value for either group.

How a group comparison might be interpreted

General statistical explanation: a comparison of group means would estimate how far apart the average endpoint values are. The estimate should be considered with its uncertainty, often expressed as a confidence interval, and with the assumptions of the chosen analysis. The registry record does not identify the statistical test, model, confidence level, or any adjustment for other variables. It is therefore not possible to attribute a particular analysis method or set of assumptions to this study.

Because allocation was non-randomized and the groups are defined by pain-relief outcome, a descriptive difference would not automatically represent a causal effect. Group membership may be related to other participant or clinical features. General statistical explanation: adjustment can sometimes account for measured factors in an analysis, but it cannot guarantee that all relevant sources of bias have been addressed. The registry record does not report whether adjusted analyses were conducted or which variables, if any, were considered.

Why measurement and timing matter

The QST assessment took place before ESI, so the recorded sensory measurement precedes the treatment described in the study. That timing is relevant to the hypothesis that baseline sensory profiles might be associated with later pain-relief categories. The endpoint itself is a difference between two sites within a participant; it is not a direct report of pain relief. The registry record does not report the timing or method used to measure post-injection pain relief, so the temporal definition of the outcome grouping cannot be fully assessed.

The endpoint is reported in degrees Celsius and is described as a mean with standard deviation. The thermode temperature at which warmth is perceived can range from 32-53 degrees Celsius. That range describes the recorded temperature scale in the registry description; it does not give the observed distribution of the arm-leg difference. The record does not report whether any QST values were missing, repeated, excluded, or deemed invalid.

Planning illustrations and study power

The registry record’s sample-size assumptions describe planning illustrations based on the observed effect, not the original design of the trial. They assume a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation; the effect to detect is a stated fraction of the observed effect. These illustrations are not observed power and should not be read as proof that the study was adequately powered or as a report of its original sample-size justification. The original sample-size justification is not reported in the registry record.

General statistical explanation: sample-size planning asks how many participants may be needed for a specified analysis to detect an effect of a chosen size under stated assumptions. The answer depends on those assumptions, including variability and the effect size being targeted. A planning calculation does not change the number enrolled, demonstrate that an effect exists, or establish that a completed study has a particular probability of a statistically significant result. The registry record does not report an original planned enrollment or an a priori effect-size target.

Overall, the available methodological description identifies the outcome, its scale, its summary measure, and the non-randomized grouping. It does not identify the inferential methods or report the outcome estimates needed to assess statistical evidence.

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(">30% Pain Relief", "<30% Pain Relief")
n   <- c(9, 11)
m   <- c(2.68, 5.67)
sp  <- c(2.92, 3.22)
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  >30% Pain Relief  9  2.680  2.920  0.435  4.925
CARM  <30% Pain Relief  11  5.670  3.220  3.507  7.833

11. Multiplicity, Missing Data and Analysis Populations

The registry record lists three outcome measures and three analyses. It does not report how those analyses map to the outcomes, which outcomes were prespecified as primary or secondary beyond the primary endpoint described, or whether any multiplicity adjustment was used. The family of hypotheses considered and the statistical plan are not reported in the registry record.

General statistical explanation: when several outcomes or analyses are examined, the chance of obtaining at least one apparently notable result can increase if each is assessed separately. A prespecified analysis plan and a suitable approach to multiplicity can help readers understand how evidence across multiple comparisons was handled. Without a reported plan, it is not possible to determine whether or how this concern was addressed in this study.

Handling of missing data is not reported in the registry record. The record does not state how many participants had usable pre-injection QST measurements, whether any measurements were missing, or how missing observations were treated. It also does not report whether the analysis included all enrolled participants or a defined subset. Therefore, the analysis population and the completeness of the primary endpoint cannot be assessed.

General statistical explanation: missingness can affect interpretation if participants with recorded measurements differ systematically from those without them. The appropriate approach depends on why measurements are missing and on the analysis question. No particular missing-data mechanism or method can be attributed to this study from the registry record.

The registry record also does not report whether there were interim analyses, a stopping rule, or a prespecified statistical analysis plan. These details should not be inferred from the completed status or from planning illustrations.

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 registry record lists serious adverse events for the two pain-relief groups. In the >30% Pain Relief group, 0 serious adverse events were reported among 9 participants at risk. In the <30% Pain Relief group, 0 serious adverse events were reported among 11 participants at risk. The registry record also lists 0 other adverse events and 0 deaths in each group. No top serious adverse-event terms are listed.

These figures describe the counts recorded for the stated groups and denominators. They are not a comparison of randomized treatment arms: the groups were formed by pain-relief category, and ESI was administered by participants’ clinical physicians rather than as a research procedure. The recorded counts therefore should not be interpreted as an estimate of a causal safety difference between treatments.

Zero recorded events does not establish that an event is impossible or that the risk is zero. The counts are limited to the participants and event information in the registry record. The record does not provide further detail about adverse-event definitions, monitoring procedures, reporting windows, or whether safety information was complete for all enrolled participants. Those details are not reported in the registry record.

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

The study addresses a focused statistical question: whether a pre-injection arm-leg difference in warm-sensation testing varies between participants placed in different pain-relief groups after ESI. The registry record gives the measurement procedure and identifies the groups, but it does not report the primary outcome values or the group comparison. As a result, it does not establish whether the recorded sensory measure was higher in either group, how large any difference was, or how precisely it was estimated.

The design also limits the kinds of conclusions that could follow from a group difference. Participants were not randomized to different treatments, and the groups are defined by pain relief rather than assigned study arms. Even if an association were reported, it would not by itself show that the QST measure caused the outcome or that it can accurately predict outcomes for future participants. The registry record does not report validation or predictive-performance analyses.

Nor does this record establish an effect of ESI compared with an alternative, since it does not describe a randomized treatment comparison. The injection was part of clinical care and was not given as a research procedure. The scientific question is about sensory profiles and outcome categories, not a controlled estimate of treatment efficacy.

General statistical explanation: an estimate, its uncertainty, and the design that produced it all matter. A small p-value, if one were reported, would not by itself establish clinical importance; a non-significant result would not by itself establish that groups are equivalent. Here, the primary numerical estimate and its uncertainty are not reported in the registry record, so neither conclusion is warranted.

The appropriate reading is therefore bounded: the registry record documents a completed, non-randomized study designed to examine a baseline sensory measure in relation to post-injection pain-relief groups. It describes how the main measure was obtained and reports limited safety counts. It does not report the primary results needed to judge the hypothesized association.

14. Why This Trial Matters Statistically

This study illustrates the distinction between measuring a potential baseline marker and evaluating a treatment. The QST measure was collected before ESI, while groups were labeled according to pain relief. That structure can address whether a baseline sensory characteristic is associated with later outcome categories, but it is different from randomizing participants to treatments and estimating a treatment effect.

The endpoint is also a derived within-participant quantity: the difference between temperature thresholds measured at the arm and painful leg. Interpreting such a measure requires attention to its definition, its scale, the variation among participants, and the statistical uncertainty around any group estimate. The registry record specifies the measure and its summary format, but does not report the numerical results needed to assess those features.

Statistically, the record highlights the importance of complete reporting. Without group estimates, uncertainty intervals, analysis details, and information about missing measurements, readers cannot distinguish a precise result from an imprecise one or assess how the analysis was conducted. The listed count of outcomes and analyses makes the absence of a reported multiplicity approach relevant as well; it does not establish that any adjustment was or was not performed.

The study also shows why outcome-based grouping should not be mistaken for randomized allocation. A difference between categories could reflect factors associated with group membership, not necessarily a distinct sensory profile that independently predicts outcome. The record does not report adjusted analyses or predictive validation that would help address those questions.

Its statistical importance lies in the question and measurement framework, and in the limits of what a registry description without numerical endpoint results can support. The study cannot be evaluated as evidence for or against its stated hypothesis from the primary outcome information recorded.

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 principal limitation for interpretation is that the registry record describes the primary endpoint but does not report its observed group results. There are no reported means, standard deviations, between-group estimates, confidence intervals, or p-values for the primary outcome. Without these, the direction, magnitude, and precision of the comparison cannot be assessed.

The study is non-randomized, and its groups are based on pain-relief categories. This does not support a randomized treatment-effect interpretation. The registry record does not describe the method or timing for determining pain relief, and its arm descriptions are incomplete. The categories >30% Pain Relief and <30% Pain Relief do not explain how exactly 30% relief would be classified.

The registry record does not report demographic or clinical characteristics of the analyzed population, the number of participants with complete QST data, missing-data handling, or an analysis-population definition. It also does not report a statistical analysis plan, model, adjustment variables, multiplicity approach, or interim analyses. These omissions prevent assessment of important aspects of the analysis and its potential sources of bias.

The enrollment is 23, while the safety record lists 9 and 11 participants at risk in the two pain-relief groups. The registry record does not explain the relationship between these counts and total enrollment. The primary outcome population and its group denominators are not reported.

The endpoint focuses on an arm-leg warm-sensation difference. The record does not report a clinical-meaning threshold for that measure or explain whether the selected QST assessment represents other sensory features. The additional outcome measures and analyses are not described in detail. These limitations restrict interpretation to the recorded study question and procedures, without supporting broader conclusions about prediction or treatment effects.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Somatosensory Profiling in Radicular Pain Patients And it's Correlation With Treatment Outcome — NCT02130258.
• Registry record last updated 2018-02-08; status last verified 2018-02.
• Results first posted 2018-02-08.
• 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

NCT02130258 is a completed, non-randomized, parallel-group study sponsored by Massachusetts General Hospital, with enrollment of 23. Participants with radicular pain were scheduled to receive ESI through their clinical physician. QST was conducted before the injection.

The primary outcome is the pre-injection difference in warm-sensation temperature between the arm and the painful leg, reported as a mean with standard deviation in degrees Celsius. Participants were grouped as >30% Pain Relief or <30% Pain Relief. The registry record does not report the primary group results or their statistical comparison.

The record lists 0 serious adverse events, 0 other adverse events, and 0 deaths in the >30% group among 9 at risk, and the same event counts in the <30% group among 11 at risk. Further details on the analysis plan, missing data, and the additional outcomes are not reported in the registry record.