Patient-Reported Acne Assessment Tool Effective, Reliable in Evaluating Severity

The Acne Core Outcomes Research Network patient global assessment (ACORN PtGA) is both reliable and valid as an evaluation tool for patient-reported acne severity, according to recent findings, with potential as a disease severity assessment option when a clinician is not accessible.1

These data were the result of new research authored in part by Delaney Griffiths, BS, from the department of dermatology at Brigham and Women’s Hospital. Griffiths et al. highlighted that while patient-reported outcomes can often function as a useful addition to clinician-reported acne severity assessments, such tools are often underused within acne clinical research.

The investigators noted that there are validated investigator global assessments for acne severity that exist, though they added that there is a lack of an analogous and fully-validated patient global assessment.2

“This study evaluates the measurement properties of a novel acne severity PtGA for potential use in clinical studies,” Griffiths and colleagues wrote.1

Acne Assessment Tool Survey

The investigators conducted a survey of patients using a single centered design, conducting their research from July 2022 - November 2023. Among those included as subjects would be individuals who were English-speaking patients, aged 18 years or older, and those being provided with outpatient treatment for their acne.

Patients would, at each clinical interaction, fill out self-administered questionnaires that were hosted on the REDCap platform at Vanderbilt University. Using these inquiries, the research team would gather demographic data for the purposes of generalizability, such as participants’ sex, age, ethnicity, race, as well as the subjects’ responses to the ACORN PtGA.

In addition, the team carried out assessments such as the Comprehensive Acne Quality of Life (CompAQ), DermSat-7 scales, the Skindex-16, and the Comprehensive Acne Severity Scale (CASS) for the purposes of evaluating participants’ maximum acne severity in the chest, face, and back regions of the body.

Convergent validity was evaluated by the investigators by comparing the ACORN PtGA to subjects’ Skindex-16, CASS, and CompAQ scores to determine construct validity. The researchers implemented Spearman’s correlation coefficient (ρ).

They classified correlation strengths as being on the weaker side (<0.4), as moderate (0.4–0.7), or as stronger (>0.7). The team analyzed responsiveness by assessing the link between PtGA score shifts from the initial to the most recent clinical visit and corresponding shifts in subjects’ Skindex-16, CASS, and CompAQ scores.

Overall, the research team analyzed data from 154 subjects, with the assessment occurring over 238 visits. The subjects had a mean age 24.4 years, with 77.3% being reported to be female and 21.4% being reported as male.

Findings on ACORN PtGA for Acne Assessment

The research team found that construct validity was supported by a strong correlation they were able to identify between the ACORN PtGA and subjects’ CASS scores (ρ = 0.704; 95% CI, 0.624–0.784). They also found that there had been moderate correlations with subjects’ scores on Skindex-16 and CompAQ, adding that these had been generally stronger than those observed for CASS.1

The team concluded that participants’ CASS and PtGA scores had weak-to-moderate correlations with participants’ Skindex symptoms (ρ = 0.460 [95% CI, 0.322–0.598] and ρ = 0.373 [95% CI, 0.225–0.522], respectively) and with their emotions (ρ = 0.546 [95% CI, 0.420–0.672] and ρ = 0.371 [95% CI, 0.222–0.520], respectively).1

In a similar vein, the investigators reported that weak-to-moderate correlations were also seen with subjects’ CompAQ symptoms (ρ = 0.526 [95% CI, 0.388–0.664] and ρ = 0.385 [95% CI, 0.229–0.541]) and their emotions (ρ = 0.378 [95% CI, 0.238–0.517] and ρ = 0.247 [95% CI, 0.088–0.405]).1

They found that participants’ ACORN PtGA and CASS scores showed higher standardized response means (0.913 [95% CI, 0.550–1.276] and 0.935 [95% CI, 0.572–1.298], respectively). This, they reported, demonstrated a stronger level of sensitivity to changes over time.1

Additionally, the researchers found that the PtGA tool had a higher standardized response mean as opposed to Skindex-16 in terms of subjects’ symptoms (0.429; 95% CI, 0.070–0.788) and emotions (0.594; 95% CI, 0.234–0.954). This was also observed for CompAQ emotions (0.787; 95% CI, 0.425–1.149), though they added that there was a lower standardized response mean compared to CompAQ symptoms (1.079; 95% CI, 0.714–1.444).1

Overall, the investigators’ findings demonstrated the robust construct validity and responsiveness of the PtGA assessment tool in its evaluation of patients’ acne severity.

“The single-center design and low representation of Black and Hispanic participants are study limitations,” they wrote. “While further studies are needed to evaluate the generalizability of these findings and other measurement properties, such as test-retest reliability, the ACORN PtGA could efficiently measure patient-reported disease activity for acne.”1

References

1. Griffiths D, Shields A, Choe J, et al. Validation of the Acne Core Outcomes Research Network Patient Global Assessment for Acne. JAMA Dermatol. Published online January 22, 2025. doi:10.1001/jamadermatol.2024.5679.
2. Tan JKL, Tang J, Fung K, et al. Development and validation of a comprehensive acne severity scale. J Cutan Med Surg. 2007;11(6):211-216. doi:10.2310/7750.2007.00037.