Validation of the Hospital Asthma Severity Score (HASS): Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Validation of the Hospital Asthma Severity Score (HASS) (NCT02782065), a registered phase not stated study. The primary outcome is Inter-rater Reliability for the Hospital Asthma Severity Score (HASS).

2. Clinical Question

The research question has two related parts. One concerns reliability: whether different clinicians give sufficiently consistent HASS scores when assessing the same patient. The other concerns validity: whether HASS scores correspond to an external measure. The brief summary describes spirometry as the gold standard for the older age group and says that comparison with spirometry in the younger age group would occur if possible, alongside PRAM, a validated tool described as most similar.

These parts answer different questions. Agreement between raters addresses consistency of scoring; it does not by itself establish that a score reflects asthma severity accurately. Comparison with spirometry or another validated tool can provide evidence about validity, but the registry record does not describe the planned validity statistics or report their results. It also does not say how the age-specific comparisons were to be combined or interpreted.

3. Trial Design

The registry identifies NCT02782065, titled “Validation of the Hospital Asthma Severity Score (HASS),” as a completed study sponsored by Boston Children's Hospital. The recorded start date is 2016-09-29, and primary completion is listed as 2020-01. Enrollment is recorded as 58. The intervention is classified as “Not an interventional study,” so this record describes an evaluation of a scoring tool rather than a randomized treatment comparison.

The brief summary says the study was intended to evaluate HASS reliability and validity in patients ages 7 to18 years old against spirometry, and in ages 2 to 6 against spirometry, if possible, and PRAM. The arm description, however, lists 165 patients aged 7 to 18 years and 30 patients aged 2 to 6 years. Those figures do not match the recorded enrollment of 58. The registry record does not explain this inconsistency, so the arm-description figures should not be treated as a reconciled account of actual enrollment.

The primary outcome is inter-rater reliability, defined as the percent agreement between a clinician serving as Rater 1 and a second clinician serving as Rater 2, regardless of which clinician served as Rater 2. Its stated timeframe is 4 years and 9 months. The record lists 5 outcome measures but 0 analyses. It does not provide an allocation method, a randomized comparison, details of the assessment schedule, or a statistical analysis plan. The record therefore supports a description of the intended tool-validation question, but not a full reconstruction of how observations were collected or analyzed.

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 Inter-rater Reliability for the Hospital Asthma Severity Score (HASS), measured over 4 years and 9 months.

The primary endpoint is inter-rater reliability for HASS, expressed as the percentage of agreement between raters. The description focuses on a patient scored by a clinician designated Rater 1 and a second clinician designated Rater 2. It says the agreement is considered regardless of which clinician served as Rater 2. The stated timeframe is 4 years and 9 months.

Agreement is used to assess whether the scoring tool produces consistent ratings across clinicians. A high level of agreement would indicate that raters tend to assign the same scores under the study's assessment conditions; lower agreement would indicate that scores vary between raters. This is a general interpretation of an agreement measure, not a finding from this registry record. The registry record does not report the numerical percentage of agreement, its uncertainty, or the number of assessments contributing to it.

Agreement should be distinguished from validity. Raters can agree with one another even if their shared ratings do not correspond closely to an external measure of asthma severity. The brief summary separately identifies planned comparisons with spirometry and PRAM for age groups, but the primary endpoint itself is defined as inter-rater agreement. The record does not report results for the planned validity comparisons or specify how they were quantified.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The primary outcome is described as the percentage of agreement between raters. In general, an agreement percentage summarizes how often raters give matching ratings under the assessment conditions. It is intuitive, but its interpretation depends on what counts as a match, how scores are categorized, and which assessments are included. The registry record does not report those operational details or a numerical result.

What does inter-rater agreement measure?

Inter-rater agreement concerns consistency across assessors. In this study, the description identifies a single clinician as Rater 1 and a second clinician as Rater 2, while allowing different clinicians to serve as Rater 2. The measure is intended to characterize how often those raters agree on HASS scoring. In general, agreement can be influenced by how clearly scoring rules distinguish categories, by the range of patient presentations assessed, and by whether raters assess the same clinical information. Those design details are not reported in the registry record, so the percentage cannot be interpreted beyond its stated definition.

Agreement is not identical to reliability under every statistical definition. A simple percentage agreement treats matching ratings as agreement, while some other reliability statistics account for the possibility that some agreement could occur by chance or account for the ordered nature of categories. This is general statistical context. The registry record names percentage agreement and does not report another agreement statistic, a chance-correction method, or the scale structure used in analysis. No alternative statistic should be assumed.

Why is agreement not the same as validity?

Reliability asks whether measurement is consistent; validity asks whether it measures the intended construct. As a general example, two raters could consistently apply the same scoring rule, yet the resulting score might not correspond closely to an external measure. Conversely, a tool's relation to an external measure does not by itself establish that different raters apply the tool consistently.

The brief summary describes spirometry as the gold standard for the ages 7 to 18 years group. It describes spirometry as a possible comparator for ages 2 to 6, along with PRAM, the most similar validated tool. The registry record does not specify a correlation, agreement, diagnostic accuracy, or other statistical method for these comparisons. It also does not report any estimates. Thus, these are stated comparison aims, not reported findings.

What does a confidence interval add?

In general, a confidence interval expresses the uncertainty around an estimate by giving a range of values compatible with the data under the method's assumptions. A narrower interval usually indicates greater precision than a wider interval, although precision does not establish that a measure is valid or that a result is important. No confidence interval for the primary endpoint is reported in the registry record. The absence of an interval means that the precision of the intended agreement estimate cannot be assessed from this record.

Precision depends on the amount and structure of usable data, not just the recorded enrollment. For a rater-agreement analysis, the relevant information includes the assessments that were actually paired and the pattern of scores. The record does not report the number of paired ratings, the number excluded, or whether all enrolled participants contributed. The enrollment count alone therefore cannot establish the precision of an agreement estimate.

How should the age groups be considered?

The stated validation aims differ by age. For ages 7 to 18 years, the brief summary names spirometry. For ages 2 to 6, it describes spirometry if possible and PRAM. In general, results for age-defined groups may not be interchangeable if measurement feasibility or clinical presentation differs. The registry record does not report age-specific estimates, group definitions beyond the stated ages, or a method for combining results. It would be inappropriate to infer a single pooled validity conclusion from the aims alone.

The participant counts also require caution: enrollment is listed as 58, whereas the arm description lists 165 patients aged 7 to 18 years and 30 patients aged 2 to 6 years. The record does not explain the mismatch. These counts cannot be used to infer how many observations entered an analysis or whether they refer to the same study population.

Finally, the record lists 0 analyses and does not report an analysis plan. It is therefore not possible to identify adjustment methods, handling of repeated assessments, missing-data procedures, or the precise statistical criteria used for reliability and validity. General statistical explanations can clarify what such methods would address, but they cannot fill in the study's unreported methods or substitute for numerical results.

10. Multiplicity, Missing Data and Analysis Populations

The registry record lists 5 outcome measures and 0 analyses. It does not identify how the outcomes were prioritized beyond naming inter-rater reliability as the primary outcome, nor does it report a statistical analysis plan. It is therefore not reported in the registry record whether any adjustment for multiple statistical tests was planned or used. Multiplicity matters in general when several outcomes or comparisons are tested, because interpreting many results can increase the chance of emphasizing a chance finding. Without the planned tests and results, the role of multiplicity cannot be assessed.

The record does not describe missing-data handling, exclusions, or analysis populations. It does not say how many participants had complete paired ratings, how missing HASS scores were handled, or whether the validity comparisons included every participant. These details are important because the usable data for an agreement analysis may differ from the overall enrollment. The recorded enrollment of 58 does not establish the number included in any analysis, especially given the separate, unreconciled figures in the arm description.

The record also does not state whether analyses were conducted by age group, whether any participants were excluded from a particular comparison, or how feasibility of spirometry in the younger group would be addressed. Such choices could affect which observations contribute to each estimate. They are not reported in the registry record, so no assumptions about the analysis population or missingness mechanism are warranted.

11. Safety Results

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

Deaths

Other (non-serious) adverse events

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

The registry lists one group, Pediatric Patients With Asthma. For that group, 58 are recorded as at risk for serious adverse events and 0 as affected; 58 are recorded as at risk for other adverse events and 0 as affected. Deaths are recorded as 0. No top serious adverse-event terms are listed.

These are registry counts, not a comparison between randomized treatment groups. The study is classified as not interventional, and the record does not describe a treatment assignment. The figures therefore should not be read as evidence comparing the safety of treatments. They also do not provide event rates, since the record does not report exposure time or further information about how adverse events were collected and monitored.

A recorded count of 0 means that no affected participants are listed in this adverse-event entry; it does not, by itself, establish that no events occurred outside the reported collection and recording process. The registry record does not report event definitions, surveillance procedures, or detailed follow-up for these safety data. The at-risk count of 58 matches the enrollment figure, but the record does not explain the relationship between these counts and the larger figures in the arm description. These data should be read narrowly as the adverse-event counts recorded for the listed group.

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

The record documents an intended evaluation of HASS in children with asthma. It identifies inter-rater percentage agreement as the primary outcome and describes planned validity comparisons involving spirometry and PRAM. The study status is COMPLETED. These registry entries describe the scope and status of the registry entry, not the size or direction of any validation result.

The record does not report the numerical primary-outcome agreement percentage, a confidence interval, or analysis results. It also does not report numerical results for comparisons with spirometry or PRAM. Consequently, the record cannot establish how consistently clinicians scored HASS, how closely HASS scores corresponded to the reference measures, or how precise any such estimates were. This is an absence of reported results in this registry record, not evidence that the tool performed well or poorly.

The age-specific aims are described in the brief summary, but the record does not provide results by age group or a method for combining groups. Enrollment is listed as 58, while the arm description lists 165 patients aged 7 to 18 years and 30 patients aged 2 to 6 years. The inconsistency is not explained, and the record does not establish which figures correspond to the participants analyzed.

The adverse-event entry records 0 serious adverse events, 0 other adverse events, and 0 deaths among the listed group, with 58 at risk in each adverse-event category. Those counts are not a treatment comparison and do not provide details about event monitoring or exposure. Overall, the record supports a description of a completed validation study and its stated questions, but not a quantitative conclusion about HASS reliability, validity, or clinical consequences.

13. Why This Trial Matters Statistically

Tool-validation studies raise statistical questions that differ from the usual treatment-effect question. For a score such as HASS, consistency across raters is important because measurements that vary substantially by assessor may be difficult to compare. The primary outcome in this record, percentage agreement, makes that reliability question explicit. Separately, comparison with spirometry or PRAM concerns whether scores relate to external measures. Keeping these concepts distinct helps prevent agreement from being mistaken for validation.

The age-specific aims also make the scope of inference important. The brief summary distinguishes ages 7 to 18 years from ages 2 to 6 years and describes different reference measures for those groups. In general, a validation conclusion depends on the population and comparison actually studied. Because the record does not report subgroup results or analysis methods, it does not support a conclusion about whether performance is consistent across ages.

Another statistical issue is transparent reporting. An outcome definition is useful, but interpreting an estimate also requires the estimate, its precision, and information about the observations included. Those results and details are not reported in the registry record. The mismatch between the enrollment figure of 58 and the arm-description counts further limits interpretation of the study population as recorded. Stating this uncertainty is more informative than treating the figures as if they were reconciled.

The registry entry therefore illustrates why validation evidence should be read in terms of both the measurement question and the reporting available. It identifies the intended reliability and validity aims, but does not provide results needed to judge their magnitude or precision. That distinction is central to statistical interpretation: a study's purpose is not itself evidence that the stated measurement properties were demonstrated.

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 of this registry entry for statistical interpretation is that it does not report results for the primary endpoint. There is no numerical percentage of agreement, uncertainty interval, or analysis result. Although the study is marked COMPLETED and the record lists 5 outcome measures, it lists 0 analyses. The registry record does not explain whether results were unavailable, not entered, or reported elsewhere.

The stated age groups and participant counts are not fully reconciled. The official title describes ages 2-18 years old, the brief summary separates ages 7 to18 years and 2 to 6 years, and the arm description lists 165 patients in the older age range and 30 in the younger age range. Enrollment is recorded as 58. The record does not explain the discrepancy or establish which participants contributed to the primary outcome.

Methodological details needed to evaluate an agreement estimate are not reported in the registry record. These include the score categories and matching rule, the number of paired assessments, the assignment or rotation of raters, and any handling of repeated ratings. The record also does not describe the statistical methods for the validity comparisons, missing data, or analysis populations.

The primary outcome timeframe is listed as 4 years and 9 months, but the record does not explain the assessment schedule within that period. It also does not report whether spirometry was feasible for the younger age group or how that condition affected comparisons. These gaps prevent a detailed assessment of precision, potential selection, or generalizability from the registry entry alone.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Validation of the Hospital Asthma Severity Score (HASS) — NCT02782065.
• Registry record last updated 2021-03-23; status last verified 2021-03.
• Results first posted 2021-02-16.
• 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

NCT02782065 is a completed, noninterventional study titled “Validation of the Hospital Asthma Severity Score (HASS),” sponsored by Boston Children's Hospital. The recorded start date is 2016-09-29, primary completion is 2020-01, and enrollment is 58. The stated purpose is to evaluate HASS reliability and validity in children with asthma.

The primary outcome is percentage agreement between two raters scoring HASS, with a stated timeframe of 4 years and 9 months. The brief summary describes comparison with spirometry for ages 7 to 18 years and comparison with spirometry, if possible, and PRAM for ages 2 to 6 years. The record lists 5 outcome measures and 0 analyses.

No numerical primary-outcome result or validity analysis is reported in the registry record. Enrollment of 58 is inconsistent with the arm description's counts of 165 patients aged 7 to 18 years and 30 patients aged 2 to 6 years; the record does not reconcile them. The listed adverse-event counts are 0 serious events, 0 other events, and 0 deaths.