This page provides an independent statistical analysis and educational interpretation of publicly reported results. ClinicalTrials.gov provides the official trial registry record. Numerical trial results on this page are restricted to the results posted in the ClinicalTrials.gov record; calculations added by Clinical Biostats are labelled as such.
1. Trial at a Glance
This page covers the registry results for Effectiveness of Lumbar Facet Joint Nerve Blocks (NCT00355914), a randomized na study. The primary outcome is Average Numeric Rating Scale.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT00355914 |
| Phase | NA |
| Condition | Low Back Pain |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | Triple |
| Enrollment | 120 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Pain Management Center of Paducah |
| Results posted | Yes |
2. Clinical Question
Population
People with low back pain. The registry record lists this condition and an enrollment of 120. Further eligibility details, such as diagnostic criteria or required symptom duration, are not reported in the registry record.
Intervention
Lumbar facet joint nerve blocks with local anesthetic, with or without Sarapin, plus non-particulate betamethasone in Group II. The arm description specifies 0.5 mL of 0.25% Bupivacaine, with or without 0.5 mL of Sarapin, and 0.15 mg of non-particulate betamethasone for Group II.
Comparator
Group 1 received lumbar facet joint nerve blocks with local anesthetic, with or without Sarapin, and is labelled Without Steroids. The arm description does not say that every participant in either group received Sarapin.
Primary question
The registry summary asks whether facet joint nerve blocks offer therapeutic value beyond the local anesthetic effect, whether adjuvant medications add relief, and whether function improves. The primary outcome listed is Average Numeric Rating Scale pain score. Numerical comparisons of this outcome are not reported in the registry record.
The comparison therefore concerns treatment packages rather than a simple contrast between receiving a procedure and receiving no procedure. Both groups are described as receiving lumbar facet joint nerve blocks and local anesthetic. The stated group distinction is the addition of betamethasone in Group II; Sarapin is described as optional in both arm descriptions. The summary also refers to Sarapin and Depo-steroids, while the arm description names non-particulate betamethasone. The record does not explain this difference in wording.
The registry summary includes function and adverse events among the questions of interest. However, the listed primary endpoint is the pain rating, and the numerical results for that endpoint and the other outcome measure are not reported in the registry record. The specific functional measure, its scoring, and its results are not reported in the registry record. The clinical question can be described from the stated aims, but the posted record does not give enough outcome estimates to quantify the observed differences between groups.
3. Trial Design
The record describes a randomized, prospective, double-blind controlled evaluation with a parallel-group model and triple masking. It lists an enrollment of 120 and a completed status. The start is recorded as 2003-08, and primary completion as 2006-07. The listed phase is NA. The sponsor is Pain Management Center of Paducah. These registry entries describe the stated structure and administrative status; they do not, by themselves, establish how the study was conducted in practice.
Participants were allocated to Group 1 Without Steroids or Group II With Steroids. Group 1 is described as receiving a lumbar facet joint nerve block with local anesthetic, with or without Sarapin. Group II is described as receiving the same local anesthetic approach, with or without Sarapin, and 0.15 mg of non-particulate betamethasone. Each arm has 60 participants listed at risk in the adverse-event record. The record does not give further details about the random sequence, allocation concealment, or the process for maintaining masking. The identities of the three masked parties are not reported in the registry record.
The primary measure is Average Numeric Rating Scale, expressed in units on a scale, with the mean and standard error specified. Its time points are baseline and 3, 6, 12, 18, and 24 months post-treatment. The measure is described as ranging from 0 for no pain to 10 for the worst pain imaginable. The registry lists two outcome measures and two analyses, but detailed descriptions of the additional measure and the analyses are not reported in the registry record.
The registry summary states that the study also aimed to evaluate function and adverse events. It does not report the participant flow, numbers completing each follow-up, or analysis populations. It also does not report the specific statistical plan, handling of repeated measurements, or approach to missing observations. Consequently, the design can be outlined from the registry descriptions, but details needed to assess implementation and analysis are unavailable 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.
Overall Study
| Stage | Group 1 Without Steroids | Group II With Steroids |
|---|---|---|
| STARTED | 60 | 60 |
| COMPLETED | 60 | 60 |
| NOT COMPLETED | 0 | 0 |
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.
| Characteristic | Unit | Group 1 Without Steroids | Group II With Steroids | Total |
|---|---|---|---|---|
| Participants analysed | 60 | 60 | 120 | |
| Age, Categorical: <=18 years | Participants | 0 | 0 | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 51 | 53 | 104 |
| Age, Categorical: >=65 years | Participants | 9 | 7 | 16 |
| Age Continuous | years | 47 (SD 15) | 46 (SD 17) | 46.7 (SD 15.3) |
| Sex: Female, Male: Female | Participants | 39 | 33 | 72 |
| Sex: Female, Male: Male | Participants | 21 | 27 | 48 |
| Region of Enrollment: United States | participants | 60 | 60 | 120 |
6. Primary Endpoint
The registry lists the primary outcome as Average Numeric Rating Scale, measured over Baseline, 3, 6, 12, 18, and 24 months post-treatment.
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | Standard Error |
| Unit | units on a scale |
| Endpoint classification | Continuous Endpoint |
The primary endpoint is Average Numeric Rating Scale pain score. The record describes a scale on which 0 means no pain and 10 means the worst pain imaginable. Scores are listed at baseline and at 3, 6, 12, 18, and 24 months post-treatment. The summary statistic is the mean, with standard error as the stated measure of dispersion.
General: A numeric rating scale turns a person's rating of pain into an ordered set of values, making it possible to describe the distribution of scores and compare group averages. A mean provides a summary of the group's scores; it does not show how every individual rated their pain. A standard error describes the precision of an estimated mean, rather than the spread of individual participants' scores. These quantities answer different questions and should not be treated as interchangeable.
Repeated assessments can describe how average scores change over follow-up, but interpreting a group difference requires the actual estimates, their uncertainty, and a clear account of how repeated measurements were analyzed. The registry record names several assessment times but does not report numerical score estimates, confidence intervals, or tests for this endpoint. It therefore does not permit a quantitative account of the observed pain-score pattern or the precision of any between-group contrast.
The endpoint is relevant to the stated aim of assessing pain, but it does not by itself measure function or adverse events. Those are separate aspects of the study's stated questions. Their specific measures and numerical results are not reported in the registry record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record identifies Average Numeric Rating Scale as the primary outcome and names the follow-up times from baseline through 24 months post-treatment. It does not report the numerical means, standard errors, between-group contrasts, confidence intervals, or p-values for those assessments. As a result, the direction, size, and precision of any pain-score difference cannot be determined from the registry record. The study's stated aims should not be mistaken for evidence that an aim was achieved.
The record lists an enrollment of 120, with 60 participants at risk in each group in the adverse-event entries. Those values describe enrollment and safety denominators as recorded; they do not establish that every participant contributed outcome data at every scheduled assessment. Numbers analyzed at each time point, withdrawals, and completion rates are not reported in the registry record. Without these details, the number of observations contributing to each endpoint estimate is unknown.
The comparisons also need to be interpreted in light of the arm descriptions. Both arms received a lumbar facet joint nerve block and local anesthetic, and either arm could include Sarapin. Group II additionally included non-particulate betamethasone. A comparison between these groups would therefore address the contrast between the described treatment packages, not the effect of the procedure versus no procedure. The registry summary asks about adjuvant medications, but the record does not provide estimates that quantify their contribution.
General: An estimated difference is more informative when accompanied by a confidence interval, which expresses a range of values compatible with the data and analysis under stated assumptions. A p-value alone would not give the size of a difference or its clinical importance. In this record, neither the estimates nor their uncertainty are reported, so no such assessment can be made.
The adverse-event entries record zero serious events and zero other adverse events in each group, with 60 at risk in each group. These are the counts as posted, not a complete description of how events were defined, sought, or classified. Death counts are listed as null, so deaths should not be interpreted as zero. The record does not include event narratives or a broader safety analysis.
In sum, the registry entry documents a randomized design, the treatment descriptions, a pain-rating outcome, follow-up times, and limited adverse-event counts. It does not report the comparative outcome estimates needed to judge the observed differences. Conclusions about benefit, absence of benefit, or precision would go beyond the numerical results recorded.
9. Statistical Methods Explained
General: Randomization is intended to make treatment assignment independent of participants' prognostic characteristics, on average. This supports a fair comparison between assigned groups, although randomization does not guarantee that groups are identical in a particular study. The record calls the allocation randomized but does not describe sequence generation, concealment, or the implementation details. Those aspects are therefore not reported in the registry record.
What does a parallel-group design mean?
General: In a parallel-group design, participants are assigned to one group and followed in that group, rather than crossing from one treatment to another as part of the design. The registry describes this study as parallel and lists two arms. The record does not give participant-level data or a flow diagram, so it is not possible to verify how many participants remained in each assigned group through follow-up.
The record describes triple masking and also calls the study double-blind in its official title. The specific people masked, the procedures used to maintain masking, and whether masking was assessed are not reported in the registry record. These terms describe the recorded design labels; they do not establish how successful masking was during the study.
How should a mean and standard error be read?
General: The mean summarizes the average score in a group. The standard error describes the precision of that estimated mean and is influenced by both variability in the observations and the amount of information contributing to the estimate. It is not the same as the standard deviation, which describes variation among individual observations. The primary outcome is specified as a mean with standard error, but the numerical values are not reported in the registry record.
For a comparison, an effect estimate should identify the contrast being made, such as a difference in mean scores between assigned groups at a specified assessment. A confidence interval around that estimate conveys uncertainty under the analysis assumptions. A p-value addresses compatibility of the observed data with a particular null hypothesis; it does not measure the probability that the null hypothesis is true, and it does not describe the size or clinical relevance of an effect. No such comparative estimates, confidence intervals, or p-values are reported in the registry record.
Why do the scheduled assessments matter?
General: Repeated measurements can show the course of an outcome over time, but they create analytical choices. An analysis might compare groups separately at each assessment, model change over time, or use another prespecified approach. These approaches answer related but not identical questions and can handle correlations among observations differently. The record lists baseline and follow-up at 3, 6, 12, 18, and 24 months post-treatment. The chosen repeated-measures model, if any, is not reported in the registry record.
Baseline scores may be used to describe initial status or to adjust comparisons, but the record does not state whether baseline adjustment was planned or performed. Nor does it report how the study handled participants with some but not all scheduled scores. A complete-case analysis, an analysis using all available measurements, and a model-based approach can rely on different assumptions. The analysis method and its assumptions are not reported in the registry record.
What can sample-size planning illustrations show?
General: A sample-size calculation is a planning exercise. It estimates how many participants may be needed for a specified statistical design, target effect, significance level, and power, under assumptions about variability and allocation. It is not a measure of the probability that a completed study found a real effect. The planning assumptions recorded for the illustrations use a two-sided significance level of 0.05, equal allocation, a normal approximation, and an effect defined as a stated fraction of the observed effect. The record describes the figures as planning illustrations rather than the trial's own design justification.
Because numerical outcome estimates and the resulting illustration values are not reported in the registry record, those assumptions alone do not establish how large a future study would need to be. Sample-size planning also depends on the endpoint, the target effect, the variability, and any allowance for the analysis design. No protocol-based sample-size justification is reported in the registry record. These illustrations, where available in the broader presentation, should be read as conditional planning scenarios, not as observed power or as evidence about the outcome.
What role does over-dispersion play?
General: Over-dispersion occurs when observed variability is greater than a statistical model expects. If a model assumes less variability than the data contain, standard errors can be too small and confidence intervals too narrow. The relevance of over-dispersion depends on the outcome and model; it is not a universal feature of continuous outcomes. The registry identifies a continuous mean outcome but does not report a model or an assessment of over-dispersion. It would therefore be inappropriate to claim that over-dispersion was present or addressed in this study.
Overall, the registry record supplies the outcome type, summary statistic, time points, and broad design labels. It does not report enough detail to reproduce or evaluate the statistical analysis. A careful interpretation should separate the general purposes of these methods from the methods actually used, which are not reported in the registry record.
10. Multiplicity, Missing Data and Analysis Populations
The primary outcome is assessed at multiple scheduled times: baseline and 3, 6, 12, 18, and 24 months post-treatment. Considering several times can raise a multiplicity question if separate statistical tests are performed, because a collection of tests may increase the chance of at least one apparently unusual result. General: Multiplicity can be handled through a prespecified primary time point, an adjustment to testing, a model that addresses the repeated measurements, or another justified strategy. The appropriate approach depends on the scientific question and analysis plan.
The registry record does not report which time point, if any, was designated as the principal treatment comparison, whether tests were adjusted for multiplicity, or how repeated observations were modeled. It lists two outcome measures and two analyses, but the specific analyses and their relationship to the outcome measures are not reported in the registry record. No multiplicity strategy is reported in the registry record.
Missing-data information is also limited. The adverse-event entries list 60 at risk per group, but the numbers with pain scores at each assessment, reasons for missing measurements, and handling of missing values are not reported in the registry record. General: Missing observations can affect interpretation when the likelihood of missingness is related to participants' outcomes or characteristics. Different methods make different assumptions, so the approach should be stated and assessed alongside follow-up completeness.
The record does not report the analysis population, such as whether participants were analyzed according to randomized assignment, nor does it report exclusions from analyses. It is therefore not possible to determine whether the posted analyses, if any, followed an intention-to-treat principle or another population definition. These omissions limit assessment of both the multiplicity of comparisons and the consequences of missing data.
11. Safety Results
The registry reports serious adverse events as affected participants divided by participants at risk.
| Arm | Participants with serious adverse events | Participants at risk | Percentage |
|---|---|---|---|
| Group 1 Without Steroids | 0 | 60 | 0.0% |
| Group II With Steroids | 0 | 60 | 0.0% |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 0% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Group 1 Without Steroids | 0 of 60 |
| Group II With Steroids | 0 of 60 |
The adverse-event record lists 60 participants at risk in Group 1 Without Steroids and 60 in Group II With Steroids. For each group, the serious adverse-event count is 0, and the other adverse-event count is also 0. These are the posted counts and denominators; they should be read as registry entries, not as proof that no event occurred outside the recording or reporting process.
The record does not report how adverse events were defined, how actively they were collected, the duration of safety follow-up, or whether events were independently adjudicated. It lists no top serious-event terms. Death counts are marked null for both groups. Null is not a count of zero, so deaths are not reported in the registry record.
General: A zero count in a group does not establish that the underlying risk is zero. The interpretation of a safety count depends on the population observed, follow-up completeness, event definitions, and ascertainment procedures. The available entries do not include event-level details or comparative uncertainty estimates. They therefore offer only a limited account of the safety data recorded for this trial.
The two groups have the same listed at-risk count and the same recorded adverse-event counts. No further safety comparison is reported in the registry record. These entries should not be used to infer that the treatment arms have equivalent safety profiles, because the record does not provide the detailed data or analysis needed for that conclusion.
12. What the Result Does, and Does Not, Mean
The registry record establishes that this was a completed, randomized, parallel-group study of lumbar facet joint nerve blocks in people with low back pain, with an enrollment of 120. It describes a local-anesthetic block approach in both arms, with or without Sarapin, and betamethasone added in Group II. It also identifies Average Numeric Rating Scale as the primary outcome and specifies follow-up through 24 months post-treatment.
Those design details explain what the study set out to compare, but they do not convey what the primary outcome showed. Numerical group means, treatment contrasts, confidence intervals, and p-values are not reported in the registry record. The results therefore cannot establish the direction or magnitude of any difference in pain scores, nor how precisely a difference was estimated. The listed aims concerning therapeutic value, adjuvant medications, and function are questions, not outcome findings.
The registry also records zero serious and zero other adverse events in each group among 60 listed at risk. This is a narrow description of posted counts. The methods for collecting and classifying adverse events are not reported in the registry record, and death counts are null rather than zero. The safety entries do not establish equivalence or rule out events that were not captured in the record.
General: A study's design can support a structured comparison, but design labels alone do not reveal the estimates or their uncertainty. Interpretation requires outcome data, analysis methods, follow-up completeness, and a clear account of how missing observations and multiple comparisons were handled. Those details are not reported in the registry record.
Accordingly, the record supports a description of the trial's stated question, design, endpoint, and limited adverse-event entries. It does not support a conclusion that one treatment package performed better, worse, or the same as the other. It also does not establish whether either package has therapeutic value beyond local anesthetic effect or whether functional improvement occurred. Those matters cannot be resolved from the reported numerical results.
13. Why This Trial Matters Statistically
This trial is statistically notable for the gap between a clearly stated comparative aim and the limited outcome information in the registry record. The record gives the randomized, parallel-group design, enrollment, two arm descriptions, and a primary pain-rating outcome with several follow-up times. Those details identify what a reader would need to evaluate, but the numerical outcome estimates and comparative analyses are not reported in the registry record.
That distinction matters because statistical interpretation depends on more than knowing which outcome was measured. The mean and standard error are specified, but without their values there is no way to assess the size or precision of the observed scores. Without a defined treatment contrast and its uncertainty, readers cannot distinguish a potentially important difference from a small or imprecisely estimated one. A study aim does not substitute for an estimate.
The scheduled assessments also make analysis choices consequential. Repeated measurements can be analyzed in different ways, and the registry does not report the method, missing-data approach, or multiplicity strategy. These are not merely technical details: they determine what comparison is being estimated and what assumptions support its interpretation. The two arm descriptions also show that the contrast is between treatment packages, not between a procedure and no procedure.
The safety entries illustrate a separate interpretive point. Zero events are recorded in both groups, but event ascertainment and death counts are not described sufficiently to support broad safety conclusions. Statistical reporting is strongest when counts are accompanied by definitions, follow-up information, and analysis context.
The trial therefore matters as an example of why registry design information and results information must be read separately. The record describes the intended comparison and endpoints, while leaving key evidence about outcome magnitude, precision, and analysis unavailable. Recognizing that boundary is essential to a measured, evidence-based reading.
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.
A central limitation of the registry record is that it does not report numerical results for the primary pain outcome. Although the mean and standard error are specified, the score estimates at baseline or follow-up, between-group contrasts, confidence intervals, and p-values are not reported in the registry record. The direction, magnitude, and precision of the observed comparison therefore cannot be assessed.
The record lists two outcome measures and two analyses, but detailed information about the second outcome and the analyses is not reported in the registry record. The registry summary refers to improvement in function, yet the functional measure, scoring method, assessment schedule, and results are not reported in the registry record. The relation between the stated questions and the listed outcomes is consequently unclear from this record.
The number enrolled and the adverse-event denominators do not show how many participants contributed outcome measurements at each follow-up. Participant flow, withdrawals, exclusions, adherence, and reasons for missing assessments are not reported in the registry record. The analysis population and missing-data methods are also not reported, limiting assessment of how incomplete follow-up could affect the comparisons.
The registry describes randomization and triple masking, while the official title calls the study double-blind. Details about sequence generation, concealment, the masked parties, and masking procedures are not reported in the registry record. The arm text also describes Sarapin as optional in both groups and names betamethasone in Group II, whereas the summary refers to Sarapin and Depo-steroids. The record does not clarify the difference in terminology or implementation.
Finally, adverse-event definitions and ascertainment methods are not reported, and death counts are null. The record does not report a multiplicity plan, a repeated-measures analysis, or a protocol-based sample-size justification. Together, these omissions restrict reproducibility and make it impossible to judge how the stated aims were tested or what the outcome data show.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Effectiveness of Lumbar Facet Joint Nerve Blocks — NCT00355914.
- Registry record last updated 2013-11-26; status last verified 2013-09.
- Results first posted 2013-11-26.
- 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.
Continue through the Clinical Biostats statistical pathway
Use this trial's endpoint as a starting point for deeper study of effect measures, confidence intervals, and sample-size planning.
18. Record Summary
NCT00355914 is a completed randomized, prospective, parallel-group evaluation of lumbar facet joint nerve blocks, sponsored by Pain Management Center of Paducah. The record lists an enrollment of 120, a start of 2003-08, and primary completion in 2006-07. It describes triple masking and lists the phase as NA.
Both groups are described as receiving lumbar facet joint nerve blocks with local anesthetic, with or without Sarapin. Group II also received 0.15 mg of non-particulate betamethasone. The primary endpoint is Average Numeric Rating Scale, summarized as a mean with standard error at baseline and 3, 6, 12, 18, and 24 months post-treatment.
Each group has 60 participants listed at risk for adverse events; zero serious and zero other adverse events are recorded in each. Death counts are null. Numerical pain-outcome comparisons, detailed analysis methods, functional outcome results, and further safety information are not reported in the registry record.