Development and Preliminary Validation of an Instrument to Measure Symptoms and Impacts in Patients with Proliferative Diabetic Retinopathy.

INTRODUCTION: Following a review of patient-reported outcome (PRO) instruments in the literature, existing PRO instruments may not adequately capture the experience of receiving treatment for proliferative diabetic retinopathy (PDR). Therefore, this study aimed to develop a de novo instrument to comprehensively assess the patient experience of PDR. METHODS: This qualitative, mixed-methods study comprised item generation for the Diabetic Retinopathy-Patient Experience Questionnaire (DR-PEQ), content validation in patients with PDR, and preliminary Rasch measurement theory (RMT) analyses. Adult patients with diabetes mellitus and PDR who received aflibercept and/or panretinal photocoagulation within 6 months of study initiation were eligible for participation. The preliminary DR-PEQ comprised four scales: Daily Activities, Emotional Impact, Social Impact, and Vision Problems. DR-PEQ items were generated using existing knowledge of patient experiences in PDR and conceptual gaps identified from existing PRO instruments. Patients indicated the level of difficulty conducting daily activities and frequency experiencing emotional impacts, social impacts, and vision problems attributed to diabetic retinopathy and its treatment in the past 7 days. Content validity was evaluated in two rounds of in-depth, semi-structured patient interviews. Measurement properties were investigated via RMT analyses. RESULTS: The preliminary DR-PEQ comprised 72 items. Overall, mean (SD) patient age was 53.7 (14.7) years. Forty patients completed the first interview; of these, 30 completed the second interview. Patients reported that the DR-PEQ was easily understood and relevant to their experience. Minor revisions, including removal of the Social Impact scale and addition of a Treatment Experience scale, were implemented to generate 85 items spanning four scales: Daily Activities, Emotional Impact, Vision Problems, and Treatment Experience. RMT analyses provided preliminary evidence that the DR-PEQ performed as intended. CONCLUSION: The DR-PEQ evaluated a broad spectrum of symptoms, functional impacts, and treatment experiences relevant to patients with PDR. Additional analyses are warranted to evaluate psychometric properties in a larger patient population.

The Patient Experience with Diabetic Retinopathy: Qualitative Analysis of Patients with Proliferative Diabetic Retinopathy.

INTRODUCTION: Few qualitative studies have explored the patient experience of daily life with proliferative diabetic retinopathy (PDR) and associated treatments. Herein, a conceptual model was developed to comprehensively examine symptoms, functional impacts, and treatment experiences in PDR. METHODS: A qualitative, mixed-methods study comprising a literature search and semi-structured interviews with clinicians and patients was conducted. Published literature and online patient resources were searched to identify concepts relevant to patients, including symptoms, functional impacts, and treatment experiences of PDR. Semi-structured interviews with experienced clinicians were conducted to identify symptoms and impacts reported by patients with PDR and to receive feedback regarding concepts identified from the literature search. A preliminary conceptual model was then developed based on findings from the literature search and clinician interviews. Patients with PDR participated in two rounds of semi-structured interviews to identify additional concepts relevant to the patient experience in PDR and associated treatments, which informed revisions to the conceptual model. Saturation of patient interviews was assessed. RESULTS: Findings from the literature search and clinician interviews yielded 109 concepts that were included in a preliminary conceptual model with three overarching domains: symptoms, impacts, and managing the disease. Clinicians confirmed concepts identified from the literature search. During interviews, patients reported a broad spectrum of symptoms (e.g., red vision); functional impacts relating to activities of daily living (e.g., reading), emotional functioning (e.g., loss of independence), and social functioning (e.g., problems recognizing faces); and treatment experiences (e.g., improves eye problems, no change) associated with PDR. Additional concepts elicited in patient interviews informed revisions to the conceptual model. Saturation was achieved in the patient sample. CONCLUSIONS: A wide variety of symptoms, functional impacts, and treatment experiences that significantly affect health-related quality of life were identified in patients with PDR. These insights are critical for understanding PDR symptomology and assessing treatment response.

Experience of Daily Life with Generalized Myasthenia Gravis: A Qualitative Investigation and Assessment of Instrument Content Validity.

INTRODUCTION: Generalized myasthenia gravis (gMG) is a rare autoimmune disease. Symptoms of gMG are diverse, and understanding of their impact on patients is limited. This qualitative study aimed to provide an in-depth exploration of patients' daily experiences of gMG. METHODS: Published qualitative studies were reviewed to identify the most important signs, symptoms, and functional impacts related to the patient experience in gMG. Semi-structured hybrid concept elicitation interviews (allowing spontaneous generation of disease concepts) and cognitive debriefing interviews (assessing the validity of existing disease assessments) were conducted with clinicians and adult patients with gMG. Signs, symptoms, and impacts were reviewed to understand which were most salient (i.e., reported by at least 50% of patients, with disturbance rating 5 or higher [10-point numeric scale]); concept saturation was also assessed. The disease conceptual model was updated. Existing clinical outcomes assessments (COAs) that capture how patients feel, function, and survive were assessed. RESULTS: Interviews with patients (n = 24) identified seven new signs and symptoms and 37 new impacts compared with the literature. Concept saturation was reached. Signs and symptoms identified by patients as most important (salient) were shortness of breath, general fatigue, muscle weakness of arms, legs, and neck, dysphonia, dysarthria, trouble swallowing liquids, choking, and heat sensitivity. Patient-identified salient impacts were work life, depression, difficulty walking, grooming hair, showering, and brushing teeth, eating, personal relationships, family life, and participating in social activities. Clinicians considered ocular, respiratory, swallowing, speech/talking, and extremity function as key clinical manifestations of gMG. Patients and clinicians found clinical outcome assessments (COAs) to be conceptually relevant and comprehensive. CONCLUSION: This research provides a holistic understanding of gMG signs, symptoms, and impacts experienced by patients, as observed by patients and clinicians. The conceptual model of gMG highlights the range of signs, symptoms, and impacts that adult patients with gMG experience in their everyday lives, emphasizing the humanistic impact and unmet needs.