Developing the National Usability-Focused Health Information System Scale for Physicians: Validation Study

BACKGROUND: Problems in the usability of health information systems (HISs) are well acknowledged, but research still lacks a validated questionnaire for measuring and monitoring different dimensions of usability of HISs. Such questionnaires are needed not only for research but also for developing usability of HISs from the viewpoint of end-user experiences. OBJECTIVE: This study aimed to develop and test the validity of the questionnaire measuring the National Usability-Focused HIS-Scale (NuHISS) among a nationally representative sample of Finnish physicians. METHODS: We utilized 2 cross-sectional data collected from a random sample of Finnish physicians in 2014 (N=3781; of which 2340 [61.9%] were women) and 2017 (N=4018; of which 2604 [64.8%] were women). Exploratory and confirmatory factor analyses (structural equation modeling [SEM]) were applied to test the structural validity of the NuHISS. As the concurrent validity measure, we used the self-reported overall quality of the electronic health record system (school grade) provided by the participants using marginal structural models. RESULTS: The exploratory factor analyses with Varimax rotation suggested that the 7-factor solution did offer a good fit to the data in both samples (C(2)=2136.14 in 2014 and C(2)=2109.83 in 2017, both P<.001). Moreover, structural equation modelling analyses, using comparative fit index (CFI), Tucker-Lewis Index (TLI), Normed Fit Index (NFI), root mean squared error of approximation (RMSEA), and Standardized Root Mean square Residual (SRMR), showed that the 7-factor solution provided an acceptable fit in both samples (CFI=0.92/0.91, TLI=0.92/0.91, NFI=0.92/0.91, RMSEA=0.048/0.049, and SRMR=0.040/0.039). In addition, concurrent validity of this solution was shown to be acceptable. Ease of use, but also all other dimensions, was especially associated with overall quality reports independent of measured confounders. The 7-factor solution included dimensions of technical quality, information quality, feedback, ease of use, benefits, internal collaboration, and cross-organizational collaboration. CONCLUSIONS: NuHISS provides a useful tool for measuring usability of HISs among physicians and offers a valid measure for monitoring the long-term development of HISs on a large scale. The relative importance of items needs to be assessed against national electronic health policy goals and complemented with items that have remained outside the NuHISS from the questionnaire when appropriate.