Health Economics and Decision Science (HEDS), School of Health and Related Research (ScHARR), University of Sheffield, West Court, 1 Mappin Street, Sheffield, S1 4DT, UK.
Centre for Health Economics Research and Evaluation, University of Technology Sydney, Sydney, NSW, Australia.
Patient. 2019 Aug;12(4):405-417. doi: 10.1007/s40271-019-00358-x.
Various self-reported or clinician-reported (as a proxy) measures exist to quantify the burden of schizophrenia on patients. Evidence of the psychometric relationship between these measures to inform their practical use is limited.
Our objective was to conduct an exploratory analysis of the construct validity of patient-reported (EQ-5D, SF-6D, WEMWBS, SQLS subscales of Psychosocial, Motivation, Symptoms) versus clinician-reported measures (PANSS, CGI-SCH, NSA-4, HoNOS-PbR) to inform future use of patient-reported measures for burden-of-illness assessment and/or economic evaluation.
In an adult patient population with schizophrenia, construct validity was assessed in relation to convergent and known-group validity. Convergent validity was assessed using Spearman's rank absolute correlation strength (ACS: weak ≤ 0.3, moderate = 0.3 < 0.5, strong ≥ 0.5) and graphically using locally weighted scatterplot smoothing (LOWESS) techniques. Known-group validity was assessed using Cohen's d absolute effect size (AES: small ≤ 0.5, moderate = 0.5 < 0.8, large ≥ 0.8). Floor and ceiling effects were assessed as a proxy of sensitivity in this cross-sectional study. Statistical significance was assessed at the 5% threshold level (p < 0.05). Across head-to-head assessments, the frequency of producing the strongest ACS, largest AES, and statistically significant results determined the best overall construct validity.
Overall, 304 patients consented to the study. In relation to statistically significant results, the SF-6D most frequently exhibited the strongest ACS and largest AES against the clinician-reported measure scores (ACS range 0.084-0.436; AES range 0.043-0.746), and the SQLS Motivation subscale most frequently exhibited the weakest/smallest values (ACS range 0.009-0.157; AES range 0.002-0.397), although these results were mixed according to the clinician-reported measure used for comparative analysis (ACS range 0.009-0.529; AES range 0.002-0.934).
The SF-6D indicated the best (mostly moderate) construct validity but still missed the negative symptoms of the condition. Although further evidence is required to confirm or refute these exploratory results, compared with the EQ-5D, the SF-6D can be self-reported to better capture generic health-related quality-of-life aspects of schizophrenia for the purpose of economic evaluation. The lack of construct validity for SQLS Motivation and Symptoms subscales were hypothesized post-hoc to be representative of the complementary information elicited by the subscales not captured by the clinician-reported measures. Therefore, the SQLS can be self-reported to capture complementary (i.e., additional) information relative to clinician-reported measures.
有多种自我报告或临床医生报告（作为代理）的措施可用于量化精神分裂症患者的负担。这些措施在实际使用中的心理测量关系的证据有限。
我们的目的是对患者报告的（EQ-5D、SF-6D、WEMWBS、心理社会、动机、症状的 SQLS 子量表）与临床医生报告的（PANSS、CGI-SCH、NSA-4、HoNOS-PbR）措施进行探索性分析，以了解患者报告的措施在疾病负担评估和/或经济评估中的实际应用。
在成年精神分裂症患者人群中，评估了与收敛和已知组有效性相关的结构有效性。使用 Spearman 秩绝对相关强度（ACS：弱≤0.3、中=0.3<0.5、强≥0.5）和局部加权散点平滑（LOWESS）技术进行收敛有效性的评估。使用 Cohen 的 d 绝对效应量（AES：小≤0.5、中=0.5<0.8、大≥0.8）进行已知组有效性的评估。在这项横断面研究中，地板和天花板效应被用作敏感性的替代指标。在 5%的阈值水平评估统计学显著性（p<0.05）。在头对头评估中，产生最强 ACS 和最大 AES 的频率以及统计学显著结果的频率决定了最佳的整体结构有效性。
总体而言，304 名患者同意参与研究。关于统计学显著结果，SF-6D 相对于临床医生报告的措施得分，最频繁地表现出最强的 ACS 和最大的 AES（ACS 范围 0.084-0.436；AES 范围 0.043-0.746），而 SQLS 动机子量表最频繁地表现出最弱/最小的值（ACS 范围 0.009-0.157；AES 范围 0.002-0.397），尽管根据用于比较分析的临床医生报告的措施，这些结果存在差异（ACS 范围 0.009-0.529；AES 范围 0.002-0.934）。
SF-6D 表明具有最佳（主要是中等）结构有效性，但仍未涵盖病情的阴性症状。尽管需要进一步的证据来证实或反驳这些探索性结果，但与 EQ-5D 相比，SF-6D 可以进行自我报告，以更好地捕捉精神分裂症的一般健康相关生活质量方面，用于经济评估。SQLS 动机和症状子量表的结构有效性不足被假设为是子量表所获取的补充信息无法被临床医生报告的措施所代表的结果。因此，SQLS 可以进行自我报告，以捕捉相对于临床医生报告的措施的补充（即附加）信息。
