2.5. Questionnaires

The workload questionnaire, NASA-TLX [54,55], is a subjective, multidimensional assessment tool that rates the perceived workload in order to evaluate the performance. It provides a general workload score based on the weighted average of six sub-scales: psychological demands, physical demands, temporal demands, performance, effort and frustration. The criteria for the composition of the subscales and their relative weight on the overall workload are detailed in the NASA manual [56]. Initially, the meaning of each of these dimensions is explained to the subject who is asked to evaluate in which position, on a twenty-point scale, the performed task is located. High scores indicate heavy requests and low scores the negligible ones. Subsequently, all possible pairs of scales are presented to the subject, who has to indicate for each pair which dimension is most relevant in determining the workload. Based on these comparisons, the authors determined some weights which are then used to calculate, starting from the initial evaluations, a general workload score ranging from 0 to 100.

The Warr’s Job Satisfaction Scale [57,58] is a questionnaire assessing job satisfaction. It is a scale composed of 15 questions, plus a 16th one that asks what level of satisfaction derives from all the factors covered in the previous questions. Each question is answered on a seven-point Likert scale, from “extremely dissatisfied” (=1) to “extremely satisfied” (=7). The total score of the 15 questions ranges from 15 to 105. The authors recommend to distinguish the intrinsic professional satisfaction, given by the seven even questions, from the extrinsic satisfaction, corresponding to the seven odd questions.

The PedsQL (Pediatric Quality of Life Inventory) Measurement Model is a modular approach to measure health-related quality of life in healthy children and adolescents and those with acute and chronic health conditions [59,60,61]. We used the questionnaire PedsQL TM 4.0 SF15 Generic Core Scales for children between 4 and 16 years of age. It is made up of 23 items spread over 4 areas of pediatric health suggested by WHO: physical, emotional, social and scholastic. Subjects have to state their degree of agreement on a five-point Likert scale from 0 (never) to 4 (almost always). The score obtained is converted into a scale from 0 to 100, where the highest score represents the highest level of functioning. The reference scores of the questionnaire are the physical health summary score (PhyHSS), psychological health summary score (PsyHSS) and total score (TS).

The Net Promoter Score (NPS) [62,63] is a measure of customer experience. It measures the proportion of “promoters” of a product, compared to its “detractors”. The number can range from −100 (all are detractors) to +100 (all are promoters). NPS is based on a single question to be asked to those who have used the product: “How likely you are to recommend this product to a friend or colleague”? Parental satisfaction, measured through the NPS questionnaire, was investigated with reference to six dimensions: therapeutic path, operator, quality of the information received, quality of assistance, technological innovation and achievement of goals. The level of parental expectations was measured by means of a questionnaire developed ad hoc and expressed as the difference between the two therapies—robotic and traditional—as two questionnaires that were administered to the parents of those patients undergoing mixed therapy, one for each of the two therapies.

The questionnaires were self-completed after a suitable explanation by trained personnel and offered to the patient, parents and physiotherapists during the time provided for by the protocol in the expected times with respect to the cycle of therapy. A complete description of the population, dimension explored, type of questionnaire and timing of administration is summarized in Table 3.

Framework of ergonomic dimensions explored, questionnaires and time of administration.