1.
Liljeroos, Maria
(författare)
Caring needs in patient-partner dyads affected by heart failure : An evaluation of the long-term effects of a dyadic psycho-educational intervention
2017
Doktorsavhandling (övrigt vetenskapligt/konstnärligt) abstract
Introduction: As medical treatment has improved, patients with heart failure (HF) now live longer and care mostly takes place at home with partners providing the main assistance. Taking care of an ill or disabled individual imposes a well-documented burden on the partner’s healthrelated quality of life. The awareness of partners’ burdensome situation is increasing, but few interventions have targeted the needs of patientpartner dyads with HF. The results have been inconclusive and give no clear guidance on how interventional programmes should be designed to improve both patient and partner outcomes.Aim: The overall aim of this thesis was to evaluate the effects of a psychoeducational intervention delivered to patient-partner dyads with HF during long-term follow-up, and to explore the dyads’ perceived caring needs.Methods: The thesis is based on four papers that used both quantitative and qualitative data. Study I and II used a randomized controlled design with a follow-up assessment after 24 months including 155 patientpartner dyads. The control group received care as usual. The intervention group received care as usual, and in addition they participated in the nurse-led psycho-educational intervention. Data was collected using questionnaires before and 24 months after the intervention, in order to determine the long-term effects on patients and partners regarding health related quality of life, perceived control, symptoms of depression and partners’ caregiver burden (I, II). A conceptual health promotion model inspired the intervention. To describe how the model was applied, a qualitative approach analysing nurses’ documentation of the sessions with 71 dyads in the intervention group (III) was used. Study IV has an explorative design. To further explore the dyads’ perceived caring needs, focus groups interviews with 19 patient-partner dyads with heart failure (IV) were performed.Results: The intervention did not have any significant effect on physical or mental health- related quality of life, depressive symptoms, or perceived control over the heart failure among the dyads (I) or caregiver burden in the partners (II) after 24 months. Furthermore, time to first event did not differ significantly between the dyads in the intervention group and the control group (I, II). As for the partners, both the intervention and control group reported decreased physical health between the baseline assessment and the 24-month follow-up (I). The intervention was composed of three components; 1) cognitive 2) supportive, and 3) behavioural component. The analysis of the nurses’ documentation confirmed the coverage of all the components and the analysis revealed a vide range of caring needs among the dyads (III). The dyads described a need to learn about HF to be able to manage everyday life. Regular outpatient clinic visits and access to telephone support were vital and both the patient and the partner need to be present at the clinic visits. Meeting others who are in the same situation and sharing the burden in nurse-led group sessions was proposed as an opportunity to support each other and others (IV).Conclusions: Over the 24-month follow-up period, the intervention had a neutral effect on health- related quality of life, depressive symptoms and perceived control over the HF among the dyads, and on partners’ caregiver burden. Considering the fact that partners serve as a critical extension of the formal healthcare system, and that both patients and partners ask for more support, it will become crucial to find new ways to support dyads affected by heart failure. This thesis may be viewed as a first step in trying to understand dyads’ perceived caring needs, and it can serve as a guide in clinical work and when designing new dyadic interventions.
2.
Khoshnood, Ardavan
(författare)
Prehospital Diagnosis and Oxygen Treatment in ST Elevation Myocardial Infarction
2017
Doktorsavhandling (övrigt vetenskapligt/konstnärligt) abstract
IntroductionPaper I: An Artificial Neural Network (ANN) was constructed to identify ST Elevation Myocardial Infarction (STEMI) and predict the need for Percutaneous Coronary Intervention (PCI). Paper II, III and IV: Studies suggest that O2 therapy may be harmful in STEMI patients. We therefore conducted the SOCCER study to evaluate the effects of O2 therapy in STEMI patients.MethodsPaper I: 560 ambulance ECGs sent to the Cardiac Care Unit (CCU), was together with the CCU physicians interpretation and decision of conducting an acute PCI or not collected, and compared with the interpretation and PCI decision of the ANN. Paper II, III, IV: Normoxic (≥94%) STEMI patients accepted for acute PCI were in the ambulance randomized to standard care with 10 L/min O2 or room air. A subset of the patients underwent echocardiography for determination of the Left Ventricular Ejection Fraction (LVEF) and the Wall Motion Score Index (WMSI). All patients had a Cardiac Magnetic Resonance Imaging (CMRI) to evaluate Myocardial area at Risk (MaR), Infarct Size (IS) and Myocardial Salvage Index (MSI).ResultsPaper I: The area under the ANN’s receiver operating characteristics curve for STEMI detection as well as predicting the need of acute PCI were very good.Paper II, III, IV: No significant differences could be shown in discussing MaR, MSI or IS between the O2 group (n=46) and the air group (n=49). Neither could any differences be shown for LVEF and WMSI at the index visit as well after six months between the O2 group (n=46) and the air group (n=41)ConclusionsPaper I: The results indicate that the number of ECGs sent to the CCU could be reduced with 2/3 as the ANN would safely identify ECGs not being STEMI.Paper II, III, IV: The results suggest that it is safe to withhold O2 therapy in normoxic, stable STEMI patients.
3.
Bergerum, Carolina, 1967-
(författare)
Patient and public involvement in hospital quality improvement interventions : the mechanisms, monitoring and management
2022
Doktorsavhandling (övrigt vetenskapligt/konstnärligt) abstract
This dissertation focuses on the mechanisms, monitoring and management of patient and public involvement in hospital quality improvement (QI) interventions. Findings from a literature review generated an initial programme theory (PT) on active patient involvement in healthcare QI interventions (Paper 1). Empirical studies were also undertaken in order to describe what was actually happening in the hospital QI teams and what patients and professionals experience influence their joint involvement (Paper 2), and to compare hospital leaders’ and managers’ experiences of managing QI interventions involving patients and the public (Paper 3). Finally, it was studied how patient-reported measures stimulate patient involvement in QI interventions in practice (Paper 4). The research had a qualitative design. The approach was descriptive and comparative, and the studies were carried out prospectively. Data were collected in two hospital organisations in Sweden and in one hospital organisation in the Netherlands. Data collection methods were a literature search (Paper 1), interviews and field observations (Paper 2 and 3) and data collection meetings (Paper 4). Altogether, 93 team meetings and meetings between the team leaders and management were attended and a total of 20 days of study visits with different forms of meetings were made. Twelve patients, 12 healthcare professionals and 17 and 8 hospital leaders and managers, respectively, participated in the interviews and data collection meetings. Realist synthesis was used to formulate the initial PT (Paper 1). Constructivist grounded theory was used to analyse and describe what was happening in the QI teams and how it was experienced by the team members (Paper 2). To compare hospital leaders’ and managers’ different, contextual meanings in Sweden and the Netherlands, the reflexive thematic analysis informed by critical realism was used (Paper 3). To order, manage and map data from 31 examples of local QI interventions associated to patient-reported measures, the framework method was used (Paper 4). The results formulate a generic PT on the mechanisms, monitoring and management perspectives of co-produced QI interventions in hospital services where patients and the public are involved. The PT provides a hypothesis on the various mechanisms at play and outcomes obtained at the different levels of hospital organisations in the process. It is argued that focus should be on experiences, interaction, relationships and dialogue, integration of context, and the matching of hospital resources to patient and public demands and needs. Subsequently, the outcome will be the resources and reasoning interplay resulting in actions and processes, experiences and knowledge, ‘product’ benefits, emotions, judgements and motivations. Monitoring constitutes an important feedback loop to enable such learnings. The PT aligns the perspectives of the clinical microsystem, improvement science and the service-dominant logic, and has a potential to explain how patient and public involvement in QI interventions might work.
4.
Ridelberg, Mikaela, 1982-
(författare)
Towards safer care in Sweden? : Studies of influences on patient safety
2016
Doktorsavhandling (övrigt vetenskapligt/konstnärligt) abstract
Patient safety has progressed in 15 years from being a relatively insignificant issue to a position high on the agenda for health care providers, managers and policymakers as well as the general public. Sweden has seen increased national, regional and local patient safety efforts since 2011 when a new patient safety law was introduced and a four-year financial incentive plan was launched to encourage county councils to carry out specified measures and meet certain patient safety related criteria. However, little is known about what structures and processes contribute to improved patient safety outcomes and how the context influences the results.The overall aim of this thesis was to generate knowledge for improved understanding and explanation of influences on patient safety in the county councils in Sweden. To address this issue, five studies were conducted: interviews with nurses and infection control practitioners, surveys to patient safety officers and a document analysis of patient safety reports. Patient safety officers are healthcare professionals who hold key positions in their county council’s patient safety work. The findings from the studies were structured through a framework based on Donabedian’s triad (with a contextual element added) and applying a learning perspective, highlight areas that are potentially important to improve the patient safety in Swedish county councils.Study I showed that the conditions for the county councils’ patient safety work could be improved. Conducting root-cause analysis and attaining an organizational culture that encourages reporting and avoids blame were perceived to be of importance for improving patient safety. Study II showed that nurses perceived facilitators and barriers for improved patient safety at several system levels. Study III revealed many different types of obstacles to effective surveillance of health care-associated infections (HAIs), the majority belonging to the early stages of the surveillance process. Many of the obstacles described by the infection control practitioners restricted the use of results in efforts to reduce HAIs. Study IV of the Patient Safety Reports identified 14 different structure elements of patient safety work, 31 process elements and 23 outcome elements. These reports were perceived by patient safety officers to be useful for providing a structure for patient safety work in the county councils, for enhancing the focus on patient safety issues and for learning from the patient safety work that is undertaken. In Study V the patient safety officers rated efforts to reduce the use of antibiotics and improved communication between health care practitioners and patients as most important for attaining current and future levels of patient safety in their county council. The patient safety officers also perceived that the most successful county councils regarding patient safety have good leadership support, a long-term commitment and a functional work organisation for patient safety work.Taken together, the five studies of this thesis demonstrate that patient safety is a multifaceted problem that requires multifaceted solutions. The findings point to an insufficient transition of assembled data and information into action and learning for improved patient safety.
5.
Hambraeus, Johan, 1959-
(författare)
Interventional pain management focused on zygapophysial joint pain : a health-economic evaluation
2023
Doktorsavhandling (övrigt vetenskapligt/konstnärligt) abstract
The pain-system is a central mechanism in our life. Chronic pain is one of the major causes of impaired health-related quality of life according to the World Health Organization’s “Global Burden of Disease”-studies. Zygapophysial joint pain has been shown to account for the pain in 30% - 50% of patients with chronic pain. There are several well-established, evidence-based methods to treat zygapophysial joint pain in the cervical and lumbar regions.This thesis originates from this and starts by exploring whether the treatment of zygapophysial joint pain can improve health-related quality of life. This thesis describes methods for the diagnosis and treatment of zygapophysial joint pain in the thoracic region that can be applied to the treatment of all pain-foci localized to the zygapophysial joints. I show that the health-related quality of life was significantly improved after treatment, and that the clinical methods used for treating thoracic pain were similar to the methods that have been established previously for cervical and lumbar pain.In order to better understand the patients’ experiences we performed qualitative interviews with patients who underwent diagnostic tests and treatments. The overall theme revealed by these interviews was that of empowerment, in which the patients were empowered by the process of diagnostic tests and treatments.The next question was whether the method was cost-effective or not. In the first cost-effectiveness analysis, the patients served as their own controls and we evaluated the results against the limits set by the Swedish national board of health and welfare. The results showed that it was cost-effective in the moderate to low range.Finally, we compared the treatment to the “gold standard” for pain management in Sweden; i.e.pain rehabilitation. We mimicked a randomized controlled trial by using propensity score weighting to compare 254 patients agains 15,357 patients registered in the Swedish National Register of Pain Rehabilitation. The results showed that interventional pain management was cost-effective in the moderate (12 months after treatment) to low (≥24 months after) range whereas pain rehabilitation was in the very high range (after 12 months) and became cost-effective in the high range after 24 months of treatment. Currently, interventional pain management accounts for just 2% of all specialized pain management procedures in Sweden. If this could be increased to 25%, it may be possible to save 106 million SEK annually, while simultaneously gain 14 quality adjusted life years of health. If an interventional pain assessment is performed early in the process, treatable patients could be directed toward interventional treatment and away from interdisciplinary pain management programs, with the potential for further reductions in costs.
6.
Engstrand, Christina
(författare)
Hand function in patients with Dupuytren’s disease : Assessment, results & patients’ perspectives
2016
Doktorsavhandling (övrigt vetenskapligt/konstnärligt) abstract
Background: Dupuytren’s Disease (DD) is a soft tissue disorder that leads to finger joint contractures affecting hand function. DD can be treated with surgery or injection and hand therapy to improve finger joint extension and thereby improve hand function. However, this does not cure the disease and recurrence is common. Previous research on DD has shown improvement in finger joint extension and in self-reported disability of the upper extremity after surgery and hand therapy for DD. However, this provides only a limited perspective on hand function, and multiple dimensions of changes in hand function (i.e. physical, psychosocial aspects and including the patients’ views of results) have not been reported as a whole.Aim: The overall aim of the thesis was to explore hand function before and after surgery and hand therapy in patients with DD, including assessment, results and patients’ perspectives.Methods: The thesis comprises three studies: Study A was a methodological study of interrater reliability in goniometry of the finger joints. Study B was a prospective cohort study with a repeated measures design. Study C was a qualitative interview study, using the model of Patient Evaluation Process and content analysis.Results: Interrater reliability was high or very high for goniometer measurement of finger joint range of motion (ROM) in patients with DD when experienced raters follow our standardized guidelines developed for the study. Changes in hand function consisted of improvement of finger joint extension while active finger flexion was significantly impaired during the first year after surgery and hand therapy. No patient reached a normal ROM, but the majority reached a functional ROM. Sensibility remained unaffected. Patients with surgery on multiple fingers had worse scar pliability than patients with surgery on a single finger. Most patients had their expectations met and were pleased or delighted with their hand function at 12 months after surgery and hand therapy. Safety issues of hand function were of greater concern than social issues. Patients reported less disability and improved health-related quality of life after surgery and hand therapy. The three variables “need to take special precautions”, “avoid using the hand in social context”, and health-related quality of life had significant importance for patients’ rating of functional recovery. Together, these variables explained 62% of the variance in functional recovery. Patients’ perspectives of undergoing a surgical intervention process were described through five categories. Previous experiences of care influenced participants’ expectations of results and the care they were about to receive. Previous experiences and expectations were used as references for appraisal of results, which concerned perceived changes in hand function, the care process, competency, and organization. Appraisal of results could also vary in relation to patient character. Appraisal of results of the intervention process influenced participants’ expectations of future hand function, health and care.Conclusions: Surgery and hand therapy for DD improve hand function and patients regain a functional ROM needed for performance of common daily activities. Despite the negative effect on finger flexion present during the first year after surgery, patients’ regards their hand function as recovered six to eight months after surgery and hand therapy. Measuring digital ROM in the finger joints with a goniometer is a reliable assessment method. However, from the patient’s perspective, it is not enough to evaluate results only in terms of digital extension or ROM. From their view, results of treatment concern consequences on daily use of the hand, what happens during the care process in terms of interaction between patient and health care provider, as well as their view of the competence and logistics of the organization providing the care.
7.
Steins, Krisjanis
(författare)
Towards Increased Use of Discrete-Event Simulation for Hospital Resource Planning
2017
Doktorsavhandling (övrigt vetenskapligt/konstnärligt) abstract
Health care systems in many countries are experiencing a growing demand while their resources remain limited. The discrepancy between demand and capacity creates many problems – long waiting times for treatment, overcrowding in hospital wards, high workload, etc. More efficient delivery of health care services can be achieved by better planning of its resources so that the mismatch between demand and capacity is minimized. Planning health care resources, including hospital resources, is difficult due to system complexity and variability in both resource availability and demand. Discrete-event simulation and other operational research methods can be used for solving planning problems in health care, and have been gaining increased attention from researchers during recent decades. Despite the growing number of academic publications, simulation appears to be less used in health care than in other application areas and only a small proportion of simulation studies is actually implemented.The aim of this thesis is to contribute to increased use of discrete-event simulation in hospital resource planning. The separate studies regarding intensive care unit capacity planning, operating room allocation strategies and the management of emergency patient flow in a radiology department highlight both the possibilities and the requirements for practical application of discrete-event simulation in hospital resource planning. The studies are described in five papers.In the first paper, the relationship between intensive care unit (ICU) occupancy and patient outcomes was investigated and the results showed that risk adjusted mortality was higher in the group of patients who were treated during high levels of occupancy. This indicates that appropriate planning of ICU resources is necessary to avoid adverse effects on patient outcomes.In the second paper, analysis of a relatively simple care chain consisting of two hospital departments – emergency and radiology – revealed a process that was not very well defined and measured. Investigation into data availability uncovered disparate information systems storing incompatible and fragmented data. It suggests that the current degree of process orientation and the current IT infrastructure does not enable efficient use of quantitative process analysis and management tools such as simulation.In the third paper, the value and possibilities of using simulation modelling in hospital resource planning were examined through the development and use of a simulation model for improved operating room time allocation and patient flow in a hospital operating department. The model was initially used for studying overcrowding in a post-anaesthesia care unit. Advanced planning logic implemented in the model enabled evaluation of several different scenarios aiming to improve the utilization of operating room resources. The results showed that it is possible to achieve slightly better and more even resource utilization, as well as provide greater flexibility in scheduling operations.In the fourth paper, a generic ICU model was developed and validated using data from four different hospital ICUs. The model was adapted and calibrated stepwise in order to identify important parameters and their values to obtain a match between model predictions and actual data. The study showed that in presence of high quality data and well defined process logic it is possible to develop a generic ICU simulation model that could provide accurate decision support for planning critical care resources.In the fifth paper, a number of factors that can contribute to successful implementation of simulation results in health care were identified. The timing of the simulation study must be right to support a critical decision, the benefit from implementation should clearly outweigh the cost of making the necessary changes and the model should be thoroughly validated to increase the credibility of the results. Staff involvement in simulation modelling activities, availability of good quality data, as well as proper incentives to improve the system contribute to implementation as well. These findings can help in establishing the conditions for successful implementation in future applications of simulation modelling in health care.
8.
Ingadóttir, Brynja
(författare)
Learning as a patient : What and how individuals want to learn when preparing for surgery, and the potential use of serious games in their education
2016
Doktorsavhandling (övrigt vetenskapligt/konstnärligt) abstract
Introduction: Surgical patients need knowledge to participate in their own care and to engage in self-care behaviour in the perioperative period which is important for their recovery. Patient education facilitates such knowledge acquisition and several methods can be used to facilitate it, for example, face-to-face education and brochures or using information technology such as website or computer games. Healthcare professionals have been slow to seize the possibilities that information technology has to offer within the field, including the use of serious games. To optimise patient education, the information is needed on the patients’ needs and preferences and what they think about the idea of using a serious game to learn about self-care.Aim: The overall aims of this thesis were to describe the knowledge expectations of surgical patients, to describe how surgical patients want to learn, and to explore the potential use of serious games in patient education.Methods: This thesis includes four studies that used both quantitative and qualitative data to describe aspects of patient learning in relation to surgery. Study I has a prospective and comparative design with survey data collected before surgery and before hospital discharge from 290 patients with osteoarthritis undergoing knee arthroplasty. Data was collected on fulfilment of knowledge expectations and related factors. Study II is a cross-‐sectional study in 104 patients with heart failure who had been scheduled for cardiac resynchronisation therapy (CRT) device implantation. Data was collected on knowledge expectations and related factors. In Study III the perceptions of 13 surgical patients towards novel and traditional methods to learn about post-operative pain management are explored in a qualitative interview study using content analysis. Study IV describes the development and evaluation of a serious game to learn about pain management with the participation of 20 persons recruited from the public. The game was developed by an interdisciplinary team following a structured approach. Data on the efficacy and usability of the game was collected in one session with questionnaires, observations and interviews.Results: Participants reported high knowledge expectations. Knowledge expectations were highest within the bio-physiological knowledge dimension on disease, treatment and complications and the functional dimension on how daily activities are affected, both of which include items on self-care. Most participants wanted to know about the possible complications related to the surgery procedure. In none of the knowledge dimensions the expectations of participants were fulfilled. Participants received most knowledge on the physical and functional issues and received least on the financial and social aspects of their illness. The main predictor of fulfilment of knowledge expectations was having access to knowledge in the hospital from doctors and nurses. Trust in the information source and own motivation to learn shaped how the participants thought about different learning methods. Although the participants were open to using novel learning methods such as websites or games they were also doubtful about their use and called for advice by healthcare professionals. To develop a serious game with the goal to learn about pain management, theories of self-care and adult learning, evidence on the educational needs of patients about pain management and principles of gamification were found useful. The game character is a surgical patient just discharged home from hospital who needs to attend to daily activities while simultaneously managing post-operative pain with different strategies. Participants who evaluated a first version of the serious game improved their knowledge and described usability of the game as high. They were positive towards this new learning method and found it suitable for learning about pain management after surgery in spite of some technical obstacles.Conclusions: Surgical patients have high knowledge expectations about all aspects of their upcoming surgery and although they prefer direct communication with healthcare professionals as a source for knowledge they might be open to try using more novel methods such as games. Preliminary short-‐term results demonstrate that a serious game can help individuals to learn about pain management, and has the potential to improve knowledge. A careful introduction, recommendation, and support from healthcare professionals is needed for implementation of such a novel method in patient education.
9.
Petersson, Jesper, 1974
(författare)
Geographies of eHealth: Studies of Healthcare at a Distance
2014
Doktorsavhandling (övrigt vetenskapligt/konstnärligt) abstract
This thesis examines the proliferation of healthcare services using information and communication technology to overcome spatial and temporal obstacles. These services are given such names as telemedicine and telecare, which are sometimes grouped together as telehealthcare under the umbrella term eHealth. My main argument is that a prevalent and overoptimistic rhetoric of how the possibilities of digitalization are expected to produce a homogenous and ubiquitous healthcare space conceals many of the spatiotemporal complexities involved in introducing telehealthcare and in the overall organizing of healthcare. To counteract such simplifications, I contend that we need a relational understanding of the technical and the geographical as always nested in the social and vice versa. With such an approach, it is arguably possible to begin to tease apart the many spatiotemporal entanglements of these innovations and to trace their political ramifications. This position is developed by integrating perspectives from science and technology studies with insights from human geography. The four constituent papers of this thesis pursue this argument in qualitatively grounded case studies of telehealthcare and its geographies. Paper I looks at various initiatives for fetal tele-ultrasonography, demonstrating that this practice cannot be reduced to a mere transparent relay for the speedy transmission of digital information across space and time. The paper investigates how its introduction could affect medical knowledge production, power hierarchies, and subject positions, for example, the status attributed to the fetal figure. Paper II traces Swedish transformations of telehealthcare. The use of telemedicine to reach those outside medicine’s range has arguably been accompanied by efforts to achieve intra-organizational streamlining via telemedicine. This process has continued with the emergence of telecare for personal use directed toward the overlapping groups of the elderly people and patients with chronic conditions. I contend that this shift can be understood through a geographical lens as attempts to save space and time by keeping as many patients as possible out of costly hospitalization and preventing them from engaging scarce specialist resources. Paper III compares four telemedicine projects in Sweden. In detailing how the purpose of practicing telemedicine differed between these projects in relation to, for example, the specifics of distance, care availability, and treated medical conditions, the paper demonstrates the existence of many versions of telemedicine. Whereas this fluidity could further the spread of telemedicine, it could also cause problems. To various actors wanting to use telemedicine in a homogenous and fixed way for national streamlining purposes, this diversity has generated confusion when they wished to align telemedicine in a preferred direction. The paper concludes that technology travels best when it can contain both fluid and fixed relationships. Paper IV argues that, whatever is claimed about creating a space- and time-independent healthcare by means of telehealthcare, the use of telecare to connect the standardized spaces of healthcare with the fluid everyday lives of elderly people and patients with chronic conditions actually works by unfolding new spaces of visibilities and establishing new temporalities as well. By investigating these spatiotemporalities, I demonstrate how these applications draw together discourses on individual freedom with medically derived algorithms and concerns about how to make best use of scarce healthcare resources.
10.
Liu, Yuanhua, 1971
(författare)
Usability Evaluation of Medical Technology: Investigating the Effect of User Background and Users' Expertise
2009
Doktorsavhandling (övrigt vetenskapligt/konstnärligt) abstract
Medical devices play a major role in diagnosis and therapeutics in the healthcare systems. The basic features of medical devices concern safety and efficient clinical performance. Nowadays, usability evaluation is an important part of the design process of medical devices. The aims of this thesis work were to investigate the effect of user profiles on usability evaluation results and to provide practical advice on choice of users as test subjects when conducting usability evaluations of medical devices. Five studies, with analytical and empirical evaluation approaches with different foci, were included in the work. In the studies, consideration was given to user background and users’ expertise as well as to user interfaces of different levels of complexity. The user background aspect was taken as the focus for the analytical evaluation approach, while users’ expertise was taken as the focus for the empirical evaluation approach. Cognitive Walkthrough was employed as an example of an analytical evaluation method to investigate user background, while usability tests were used as an example of empirical evaluation method to investigate users’ expertise. The results showed that medical device user background settings can influence the outcome of an analytical evaluation results, i.e. when more ergonomic factors were included in the user background settings, a wider range of usability problems were detected. User expertise is an important factor for the results of empirical usability tests. Users’ familiarity with tasks can be used as an important criterion for classification of user expertise. The quantitative analysis of the empirical evaluations implies that the effect of users’ expertise may be invisible when interacting with a simple user interface, but visible when interacting with a more complex user interface. Expert users outperformed novice users when interacting with a complex interface but not when interacting with a simple interface.The qualitative analysis of verbal explanations and statements, causes of errors and redesign proposals stressed the differences between novice and expert users in terms of decision-making, presentation and judgment, which implied that expert users’ use experience and novice users’ interaction experience differ in contributing to product design and development. Insufficient domain and interaction knowledge were consistently identified as typical causes of errors for novice users. The differences of information organization between previously experienced user interfaces and the interfaces interacted in the usability tests affected expert users’ task completion. Expert users made task-related errors due to terminology issues and interaction-related errors due to their ‘old’ mental model of how to interact with the user interface. Based on the results, different strategies are suggested to be used when choosing test subjects for usability evaluations in different interaction situations. A guideline and some practical advices were proposed as well to medical industrial companies about how to conduct usability evaluations on medical devices.
