Enhancing Patient-Reported Outcome Measures for Drug Hypersensitivity: A Validated 6-Item Quality-of-Life Questionnaire for Patients With Drug Hypersensitivity

BACKGROUND

Drug hypersensitivity reactions (DHRs) can significantly impair patients' health-related quality of life (HRQoL). However, tools for HRQoL assessment for patients with DHR are time-consuming and remain underutilized.

OBJECTIVE

To develop and validate an optimized version of the Drug Hypersensitivity Quality-of-Life Questionnaire (DrHy-Q) designed for everyday clinical use.

METHODS

Item response theory (IRT), a statistical framework for psychometric measurement, was used to evaluate the 15 questions from the original DrHy-Q for their respective item difficulty, discrimination, and information using prospective data from 243 patients with histories of suspected/confirmed DHR before allergy workup. Accordingly, the best-performing items were identified to develop a 6-item optimized version (DrHy-Q6), which was subsequently validated with another prospective cohort of 156 patients.

RESULTS

All 15 items of the original DrHy-Q demonstrated satisfactory parameters in IRT analysis, including very high discrimination (>1.7), appropriate difficulty (in between -1.5 and 1.5), and good information (a high and broad peak in the information curve). Six items with top-ranked IRT parameters were identified to construct an optimized version, which we named the DrHy-Q6. The DrHy-Q6 demonstrated a 1-factor structure with an improved fit compared with the original DrHy-Q (comparative fit index = 0.985, Tucker-Lewis index = 0.974), excellent convergent validity (unadjusted Pearson correlation with the full version = 0.955; adjusted = 0.894, P < .001), reliability (Cronbach's α and McDonald's ω = 0.93), divergent validity (Pearson correlation with all Short Form 12-item Health Survey Version 2 subscales <0.60, P < .001), and discriminant validity (significantly higher scores with multiple DHR labels [42.45 ± 27.26 vs 32.93 ± 26.66], P = .013).

CONCLUSIONS

From an IRT perspective, the DrHy-Q and all its constituent items are psychometrically valid for HRQoL assessment. We propose an optimized 6-item version (DrHy-Q6) as an abbreviated alternative for assessing HRQoL in patients with DHR, especially for routine use in clinical practice. Patients and physicians may benefit from its streamlined length and simpler scoring algorithm.

Severe cutaneous adverse reactions

Severe cutaneous adverse reactions (SCARs), which include Stevens-Johnson syndrome and toxic epidermal necrolysis, drug reaction with eosinophilia and systemic symptoms (also known as drug-induced hypersensitivity syndrome), acute generalized exanthematous pustulosis, and generalized bullous fixed drug eruption, are life-threatening conditions. The pathogenesis of SCARs involves T cell receptors recognizing drug antigens presented by human leukocyte antigens, triggering the activation of distinct T cell subsets. These cells interact with keratinocytes and various immune cells, orchestrating cutaneous lesions and systemic manifestations. Genetic predisposition, impaired drug metabolism, viral reactivation or infections, and heterologous immunity influence SCAR development and clinical presentation. Specific genetic associations with distinct SCAR phenotypes have been identified, leading to the implementation of genetic screening before prescription in various countries to prevent SCARs. Whilst systemic corticosteroids and conventional immunomodulators have been the primary therapeutic agents, evolving strategies, including biologics and small molecules targeting tumour necrosis factor, different cytokines, or Janus kinase signalling pathways, signify a shift towards a precision management paradigm that considers individual clinical presentations.

Drug Hypersensitivity Quality of Life Questionnaire: validation procedures and first results of the Portuguese version

BACKGROUND

Hypersensitivity reactions to drugs are unpredictable and can be very complex and severe, even life threatening. Assess its impact on patient's health related quality of life (HRQoL) is crucial. The Drug Hypersensitivity Quality of Life Questionnaire (DrHy-Q) is the only validated disease-specific HRQoL questionnaire. We aimed to translate and cross-cultural validate the DrHy-Q to the Portuguese population. It was also our purpose to determine the impact of drug hypersensitivity on patients' HRQoL.

METHODS

The translation and cross-cultural adaptation of the DrHy-Q to Portuguese was performed according to standards. Reliability of the DrHy-Q Portuguese version was assessed in terms of internal consistency and test-retest reliability. Structural validity, divergent validity (with a generic health related QoLQ-PGWBI) and discriminant validity were also evaluated. Forty patients accepted to participate in the validation phase. The Portuguese version of the DrHy-Q was applied to 260 consecutively adult patients, studied in our Department for suspected drug hypersensitivity.

RESULTS

The Portuguese DrHy-Q showed adequate internal consistency (Cronbach's ɑ = 0.938), good test-retest reliability [ICC = 0.713 (95% CI 0.488-0.850] and one-dimensional structure. No significant correlation was found between the DrHy-Q and the PGWBI total scores (r = - 0.010, p = 0.957). Two hundred of patients completed the study: 78.5% female; mean age = 44 ± 15 years. Mean DrHy-Q score was 36.8 ± 12.6. Two clinical factors significantly predict DrHy-Q total score: clinical manifestations and number of suspected drugs. Patients with anaphylaxis (β = 11.005; 95% CI 5.523; 16.487), urticaria/angioedema (β = 7.770; 95% CI 2.600; 12.940) and other manifestations (β = 7.948; 95% CI 1.933; 13.962) are more likely to have higher DrHy-Q total score than patients with maculopapular exanthema. Patients with ≥ 2 suspected drugs are also more likely to have worse QoL (β = 7.927; 95% CI 3.687; 12.166).

CONCLUSION

The Portuguese version of DrHy-Q revealed adequate validity and reliability, indicating that it is appropriate to assess the impact of drug hypersensitivity on patients' HRQoL, providing data for a better comprehension and management of our patients. Moreover, our results highlight that the severity of the drug hypersensitivity reaction and the number of suspected drugs have impact on patient's DrHy-QoL.

Reliability and validity of the Thai Drug Hypersensitivity Quality of Life Questionnaire: a multi-center study

OBJECTIVE

To adapted the Drug Hypersensitivity Quality of Life (DrHy-Q) Questionnaire from Italian into Thai and assessed its validity and reliability.

DESIGN

Prospectively recruited during January 2012-May 2017.

SETTING

Multicenter; six Thai tertiary university hospitals.

STUDY PARTICIPANTS

Total of 306 patients with physician-diagnosed drug hypersensitivity.

INTERVENTIONS

Internal consistency and test-retest reliability were evaluated among 68 participants using Cronbach's ɑ and intra-class correlation coefficient (ICC). The validity of Thai DrHy-Q was assessed among 306 participants who completed World Health Organization Quality of Life-BREF (WHOQOL-BREF-THAI). Construct and divergent validities were assessed for Thai DrHy-Q. Known-groups validity assessing discriminating ability was conducted in Thai DrHy-Q and WHOQOL-BREF-THAI.

MAIN OUTCOME MEASURES

Validity; reliability; single vs. multiple drug allergy; non-severe cutaneous adverse reactions (SCAR) vs. SCAR.

RESULTS

Thai DrHy-Q showed good reliability (Cronbach's ɑ = 0.94 and ICC = 0.8). Unidimensional factor structure was established by confirmatory factor analysis (CFI&TLI = 0.999, RMSEA = 0.02). Divergent validity was confirmed by weak correlation between Thai DrHy-Q and WHOQOL-BREF-THAI domains (Pearson's r = -0.41 to -0.19). Known-groups validity of Thai DrHy-Q was confirmed with significant difference between patients with and without life-threatening SCAR (P = 0.02) and patients with multiple implicated drug classes vs. those with one class (P < 0.01); while WHOQOL-BREF-THAI could differentiate presence of life-threatening SCAR (P < 0.01) but not multiple-drug allergy.

CONCLUSIONS

Thai DrHy-Q was reliable and valid in evaluating quality of life among patients with drug hypersensitivity. Thai DrHy-Q was able to discriminate serious drug allergy phenotypes from non-serious manifestations in clinical practice and capture more specific drug-hypersensitivity aspects than WHOQOL-BREF-THAI.