Developing Angelman syndrome-specific clinician-reported and caregiver-reported measures to support holistic, patient-centered drug development.

BACKGROUND: Angelman syndrome (AS) is a rare, heterogenous neurogenetic condition, which significantly impacts the lives of people with AS and their families. Valid and reliable measures reporting key symptoms and functional impairments of AS are required to support development of patient-centered therapies. We describe the development of clinician- and caregiver-reported, AS-specific Global Impression scales for incorporation into clinical trials. Best practice US Food and Drug Administration guidance for measure development was followed with input from expert clinicians, patient advocates, and caregivers during content generation and refinement. RESULTS: Initial measurement domains for the Symptoms of AS-Clinician Global Impression (SAS-CGI) and the Caregiver-reported AS Scale (CASS) were identified from a conceptual disease model of AS symptoms and impacts, derived from interviews with caregivers and clinicians. Two rounds of cognitive debriefing (CD) interviews were performed; clinicians debriefed the SAS-CGI, with patient advocates and caregivers debriefing the CASS to ensure relevance and comprehension. Feedback was used to refine items and ensure wording was age-appropriate and captured AS-specific symptoms, as well as associated impacts and functional impairments. The SAS-CGI and CASS capture global assessments of seizures, sleep, maladaptive behaviors, expressive communication, fine and gross motor skills, cognition, and self-care, which were determined by clinicians, patient advocates, and caregivers to be the most challenging aspects of AS. Additionally, the measures include items for assessing overall AS symptoms and the meaningfulness of any change. In addition to ratings for severity, impact, and change, a notes field was included in the SAS-CGI to provide the rationale for the chosen rating. CD interviews confirmed the measures covered key concepts of AS from the perspective of clinicians and caregivers, and demonstrated that the measures' instructions, items, and response options were clear and appropriate. Interview feedback informed adjustments to the wording of the instructions and the items. CONCLUSIONS: The SAS-CGI and CASS were designed to capture multiple AS symptoms, reflecting the heterogeneity and complexity of AS in children 1 to 12 years old. These clinical outcome assessments have been incorporated into AS clinical studies, which will allow for the evaluation of their psychometric properties and inform further refinements if needed.

Summary of Research: Development and Validation of the Insomnia Daytime Symptoms and Impacts Questionnaire (IDSIQ).

This is a summary of the original article 'Development and Validation of the Insomnia Daytime Symptoms and Impacts Questionnaire (IDSIQ)'. Individuals with insomnia are best positioned to assess the impact of insomnia on their quality of life. Patient reported outcomes (PROs) are self-reported health measures created to allow people to record their experience of their disease. Chronic insomnia has a major impact on daytime functioning for patients, and on their quality of life. This summary of research provides an overview of a previously published article detailing the development and evaluation of the Insomnia Daytime Symptoms and Impacts Questionnaire (IDSIQ), as a tool to allow people with insomnia to report their experience of the impact on their daytime functioning.

Exploring Disease Remission and Bowel Urgency Severity Among Adults with Moderate to Severe Ulcerative Colitis: A Qualitative Study.

Purpose: Achieving and maintaining symptom control is a key treatment goal in ulcerative colitis (UC). Bowel urgency is an important symptom of UC, thus measurement of urgency is critical. This research explored the patient experience of UC and "remission" in UC, with a focus on urgency, and cognitively debriefed the Urgency Numeric Rating Scale (NRS), including score interpretation and examination of meaningful improvement. Patients and Methods: Semi-structured hybrid concept elicitation and cognitive debriefing interviews with adults with moderately-severely active UC were conducted to explore experiences of UC and urgency, as well as examine meaningful improvement and score interpretation of the Urgency NRS. Purposive sampling was used to identify 20 eligible adult participants with UC. Concept elicitation data were analyzed using thematic analysis, and a deductive approach was used to analyze cognitive debriefing data. Thematic analysis was also applied to meaningful change-related data. Results: Twenty participants were interviewed (average age = 42.6 years old, 50% male); 14 with moderately active (70.0%) and 6 with severely active UC (30.0%). Disease remission was not consistently defined by participants and description varied in terms of definition (absence vs not complete absence of symptoms), duration (months vs days) and key symptoms to consider. Urgency was a prominent symptom for all participants, with 8 (40.0%) identifying it as the most bothersome aspect of UC. No issues were identified with the Urgency NRS. Participants were able to define different levels of urgency severity, describe how they relate to daily life impacts, and score them differently on the Urgency NRS. Participants were also able to reflect urgency improvement on the NRS and discuss how small changes in numeric ratings of urgency can reflect meaningful change in the symptom burden of their UC. Conclusion: The Urgency NRS is a content valid and interpretable measure to assess bowel urgency severity.

Comparability of a provisioned device versus bring your own device for completion of patient-reported outcome measures by participants with chronic obstructive pulmonary disease: quantitative study findings.

OBJECTIVE: To quantitatively compare equivalence and compliance of patient-reported outcome (PRO) data collected via provisioned device (PD) versus bring your own device (BYOD). METHODS: Participants with stable chronic obstructive pulmonary disease (COPD) completed the EXAcerbations of Chronic Pulmonary Disease Tool (EXACT®) daily and COPD Assessment Test™ (CAT) and Patient Global Impression of Severity (PGIS) of COPD weekly on either PD or BYOD for 15 days, then switched device types for 15 days. EXACT was scored using the Evaluating Respiratory Symptoms in COPD (E-RS®: COPD) algorithm and equivalence assessed using intraclass correlation coefficients (ICCs) adjusting for cross-over sequence, period, and time. Two one-sided tests (TOSTs) used ICC adjusted means with 10%, 20%, and 40% of total score tested as equivalence margins. Compliance and comfort with technology were assessed. Equivalence across 3 device screen sizes was assessed following the second completion period. RESULTS: Participants (N = 64) reported high comfort with technology, with 79.7% reporting being "quite a bit" or "very" comfortable. Weekly compliance was high (BYOD = 89.7-100%; PD = 76.9-100%). CAT and E-RS: COPD scores correlated well with PGIS (r > 0.50) and demonstrated equivalence between PD and BYOD completion (ICC = 0.863-0.908). TOST equivalence was achieved within 10% of the total score (p > 0.05). PRO measure scores were equivalent across 3 different screen sizes (ICC = 0.972-0.989). CONCLUSIONS: Measure completion was high and scores equivalent between PD and BYOD, supporting use of BYOD in addition to PD for collecting PRO data in COPD studies and in demographically diverse patient populations.

Comparability of a provisioned device versus bring your own device for completion of patient-reported outcome measures by participants with chronic obstructive pulmonary disease: qualitative interview findings.

BACKGROUND: There is interest in participants using their own smartphones or tablets ("bring your own device"; BYOD) to complete patient-reported outcome (PRO) measures in clinical studies. Our study aimed to qualitatively evaluate participants' experience using a provisioned device (PD) versus their own smartphone (BYOD) for this purpose. METHODS: Participants with chronic obstructive pulmonary disease (COPD) were recruited for this observational, cross-over study and completed PRO measures daily on one device type for 15 days, then switched to the other device type to complete the same measures for another 15 days. After each 15-day period, semi-structured interviews were conducted about their experience with the device. RESULTS: Of 64 participants enrolled, the final qualitative analysis populations comprised those who participated in an interview without protocol violations. Thus, the qualitative longitudinal population (LP) included n = 57 (89%), while the qualitative cross-sectional population (CSP) included n = 60 (94%). CSP participants found both device types easy to use. Twenty CSP participants (33%) reported missing data entry on at least one day when using PD, and 24 (40%) reported missing at least one day when using BYOD. In the LP, preference for one of the device types was somewhat evenly split; 45.6% (n = 26) preferred PD and 50.9% (n = 29) preferred BYOD. The most common reason for preferring PD was that it was "dedicated" to the study; the "convenience" of carrying a single device was the main reason for preferring BYOD. CONCLUSION: The findings from the interviews demonstrated few differences in participants' experience completing PRO measures on a PD versus BYOD. Our study supports the use of BYOD as a potential addition to PD for collecting PRO data and contributes evidence that BYOD may be employed to collect PRO data in demographically diverse patient populations.

A Patient-Centered Conceptual Model of Symptoms and Their Impact in Early Parkinson's Disease: A Qualitative Study.

BACKGROUND: Individuals with Parkinson's disease (PD) develop a significant disease burden over time that contributes to a progressive decline in health-related quality of life. There is a paucity of qualitative research to understand symptoms and impacts in individuals with early-stage PD (i.e., Hoehn and Yahr stage 1-2 and ≤2 years since diagnosis). OBJECTIVE: The collection of qualitative data to inform the selection of clinical outcome assessments for clinical trials is advocated by regulators. This patient-centered, multistage study sought to create a conceptual model of symptoms and their impact for individuals with early-stage PD. METHODS: Symptoms and impacts of PD were gathered from a literature review of qualitative research, a quantitative social media listening analysis, and qualitative patient concept elicitation interviews (n = 35). Clinical experts provided input to validate and finalize the concepts. RESULTS: The final conceptual model consisted of 27 symptoms categorized into 'motor' or 'non-motor' domains, and 39 impacts divided into five domains. Most frequently reported symptoms in early-stage PD were 'tremors' (89%), 'stiffness and rigidity', and 'fatigue' (69%, both). Most frequently reported impacts included 'anxiety' (74%), 'eating and drinking' (71%), followed by 'exercise/sport' and 'relationship with family/family life' (66%, both). CONCLUSION: This study provides initial insights relating to the symptom and impact burden of early-stage PD patients. The conceptual model can be used to help researchers to develop and select optimal patient-centered outcomes to measure treatment benefit in clinical trials. These findings could inform future qualitative research and the development of outcomes specifically for early-stage PD patients.

A qualitative study to explore symptoms and impacts of pediatric and adolescent Crohn's disease from patient and caregiver perspective.

BACKGROUND: Crohn's disease (CD) is a chronic inflammatory condition of the gastrointestinal tract that affects people across the age spectrum but often starts in childhood or early adulthood. Despite this, almost all published research examining the symptomatic and health-related quality of life (HRQL) experiences of CD has been conducted in an adult population. Studies providing a comprehensive overview of the lived experience of pediatric and adolescent CD are virtually non-existent. The experiences of younger children aged 2-7 years are especially unknown. RESULTS: A total of 49 participants (31 children and 18 parents) were interviewed. This included 11 dyads (i.e., parents and children from the same family). Analyses were conducted based on reporter-type (patient self-report vs parent observer-report) and age subgroups (ages 2-4 vs 5-7 vs 8-11 vs 12-17). Key symptoms were identified across the age subgroups and reporter types. Abdominal/stomach pain, passing gas/feeling gassy, diarrhea/liquid stools, fatigue/tiredness, bowel urgency, blood in stools, stomach cramping, constipation, and incomplete evacuation were discussed most frequently. The most common HRQL impacts included impact on physical activity, school, social life, and mood (i.e., feeling sad/low), and were mostly consistent between reporter type and across age spectrum. Concept agreement between parents and children in the dyad analysis was > 60% for most symptoms and impacts. CONCLUSIONS: Qualitative interviews revealed the substantial symptom and HRQL burden of pediatric CD from the child and parent perspectives and that disease experiences were largely consistent across the age range and based on both reporter perspectives. This is an important first step towards implementing a robust measurement strategy for the assessment of symptoms and HRQL impacts in pediatric CD.

Development and Validation of the Insomnia Daytime Symptoms and Impacts Questionnaire (IDSIQ).

BACKGROUND AND OBJECTIVE: Chronic insomnia has major consequences for daytime functioning, yet no fully validated patient-reported outcome instrument for once-daily assessments is available to measure these consequences. This study describes the development and psychometric evaluation of the Insomnia Daytime Symptoms and Impacts Questionnaire (IDSIQ). METHODS: The Daytime Insomnia Symptom Scale (DISS), an existing 20-item instrument for assessing daytime functioning, was modified to give an 18-item version of the IDSIQ (IDSIQ-18) based on iterative qualitative interviews with 54 subjects with insomnia and expert input. The construct validity and other psychometric properties of the IDSIQ-18 were analyzed based on an interventional study (NCT03056053) in which subjects with insomnia received zolpidem (5 or 10 mg) daily for 2 weeks and an observational study among subjects with no diagnosis of insomnia (good sleepers). Participants in both studies completed the IDSIQ-18 daily for 2 weeks. Exit interviews were conducted with a sample of subjects who completed the interventional study to elicit concepts defining the experience of insomnia, to assess understanding of the response scales, and to determine meaningful change thresholds. Exploratory factor analysis and Rasch analysis were conducted to further assess the structure and latent model for the scoring of the final IDSIQ instrument. Further psychometric evaluation of the final IDSIQ was then conducted. RESULTS: Subjects in both the interventional study (N = 114) and observational study (N = 103) were predominantly female (65% for subjects with insomnia and 60% for good sleepers). Mean age was 51 years for subjects with insomnia and 45 years for good sleepers. Subjects in the exit interviews (N = 41) demonstrated a good understanding of the IDSIQ-18 response scales. Day 1 mean scores were higher (worse) in subjects with insomnia compared with good sleepers. Based on inter-item correlation, exploratory factor, and Rasch analyses and review of the qualitative data, four items were removed. This yielded the final IDSIQ, with 14 items comprising three domains: Alert/Cognition, Mood, and Sleepiness. The domain structure was determined in a confirmatory factor analysis. Evidence of internal consistency reliability was strong: day 1 Cronbach's alpha was 0.917 for IDSIQ total score and 0.806-0.918 for the domains. Test-retest reliability, assessed for subjects with insomnia with no change on the Patient Global Assessment of Disease Severity scale between day 1 and day 8, was also good (intra-class correlation coefficient 0.856-0.911). Meaningful change thresholds derived for this sample using anchor-based approaches were 20 for IDSIQ total score, 9 for the Alert/Cognition domain, 4 for the Mood domain, and 4 for the Sleepiness domain. CONCLUSIONS: These studies, which closely followed Food and Drug Administration Guidance for Industry on patient-reported outcome measures, support use of the IDSIQ as a fit-for-purpose measure for deriving valid and reliable endpoints in insomnia clinical research trials and real-world studies.

Qualitative research to explore the symptoms and impacts experienced by children with ulcerative colitis.

BACKGROUND: Ulcerative Colitis (UC) is a chronic gastrointestinal disease that often presents during one's most productive years and is characterized by colon inflammation. Key symptoms and impacts in adults are well-known, however, experiences among pediatric populations have not been well documented. The purpose of this study was to understand the health-related quality of life and symptomatic experience of children (2-11 years) living with UC. METHODS: Qualitative, semi-structured face-to-face interviews were conducted. Children aged 5-11 years were interviewed, as well as their parents/caregivers in matched dyads. Parents/caregivers of children aged2-4 years were interviewed within a parent/caregiver-only cohort. All participants were recruited from the United States. Interviews were coded using thematic analysis. RESULTS: Key symptoms and impacts reflecting the lived experience of UC were identified following thematic analysis, generating a conceptual model. A total of 32 participants (20 parents/caregivers and 12 children) were interviewed. Results identified a substantial burden of UC in children. All children and parents/caregivers reported that they/their child experienced stomach/abdominal pain. Other symptoms discussed by over 75% were blood in stool, diarrhea/loose stools, stool urgency, incomplete evacuation, stool frequency, and feeling gassy/passing gas. The most frequently discussed impacts by over 75% of participants were on emotional and practical aspects, seriously affecting quality of life. CONCLUSIONS: Qualitative analysis of the interviews identified a substantial burden of UC on children, with a profound impact on their lives. The symptomatic experience is reflective of adults and adolescents. A high level of agreement between parents/caregivers and children was demonstrated regarding the perception of the presence or absence of symptoms. Children aged 8-11 years showed higher levels of agreement with parents/caregivers than did younger children, indicating appropriateness of self-report of symptom data in the 8-11 years age group.

A qualitative study exploring the health-related quality of life and symptomatic experiences of adults and adolescents with ulcerative colitis.

BACKGROUND: Ulcerative colitis (UC) often first presents during adolescence and early adulthood. Primary symptoms of UC are well known, yet similarities and differences of disease experience in adults and adolescents are not well characterized. METHODS: To understand the health-related quality of life (HRQoL) and symptomatic experience of UC, in-depth interviews were conducted in the US with 21 adults (20-70 years) and 14 adolescents (12-17 years). Eligibility and medical history were confirmed by clinician report. A previously conducted literature review and resultant conceptual model informed the discussion guide to explore symptoms and HRQoL. Age appropriate creative tasks ("animal" task and collage) were employed to facilitate discussion. Transcripts and collages were subjected to thematic analysis using ATLAS.ti software. RESULTS: Clinician-reported UC severity included 24% mild, 38% moderate, 38% severe among adults; and 64% mild, 29% moderate, 7% severe among adolescents. Among adults, 52% were female, 67% were white. Among adolescents, 50% were female, 71% were white. During analysis it was noted that all participants reported stomach/abdominal pain. Other key symptoms identified were frequent bowel movements, diarrhea, blood in stools, sudden need for bowel movement, stomach cramping, bloating, and feeling gassy/passing gas (≥75% of participants). Key impacts identified were embarrassment, dietary limitations, having to plan around UC, worry/fear, anger, low mood/depression, and relationship with others, (≥75% of participants). In creative tasks, animals were chosen to represent their UC and content included in the collages reflected the most commonly discussed themes from the interviews. Only adults discussed feeling dehydrated, while only adolescents discussed the impact of UC on school life. CONCLUSIONS: Open-ended interviews highlighted the HRQoL and symptomatic experiences of UC from the patient's perspective, which were similar between adult and adolescent UC patients.

Exploring content and psychometric validity of newly developed assessment tools for itch and skin pain in atopic dermatitis.

BACKGROUND: Atopic dermatitis (AD) is a common skin disorder characterized by chronic inflammation, altered skin barrier function, and inflammatory cell skin infiltration that decreases health-related quality of life (HRQoL). The study objective was to understand the patient perspective of AD burden and determine suitable patient-reported outcome (PRO) measures. METHODS: This mixed methods study involved the collection of qualitative and quantitative information from adults (≥ 18 years old) and adolescents (12 - 17 years old) with clinician-confirmed AD regarding their experiences of AD symptoms and its impact on HRQoL. The first part of the study included three stages: in-person concept elicitation (CE) interviews, a 2-week daily electronic diary (eDiary) study, and in-person cognitive debriefing (CD) interviews. An Itch numeric rating scale (NRS) (v1.0) and a Skin Pain NRS (v1.0) evaluation during CD interviews required participants to think about their 'worst' itch and 'worst' skin pain in the past 24 h. Other PRO measures allowed for psychometric testing. The second part of the study involved telephone-depth interviews (TDIs) and qualitative feedback from participants who had not participated in the CD interviews. Qualitative data were thematically analyzed. Psychometric evaluation of NRS measures was performed using eDiary data. RESULTS: In the CE interviews, itch and/or itching and skin pain were the most prevalent symptoms consistently discussed by participants. Both NRS measures demonstrated strong psychometric reliability and were applicable across ages with suitable concurrent validity. During the CD interviews, some participants focused their answers on their 'average' itch/itching in the past 24 h, rather than their 'worst' itch. Some participants answered the Skin Pain NRS thinking about general pain or other types of pain, rather than skin pain specifically. Consequently, modifications to both measures addressed these issues and re-tested as paper-and-pen versions in subsequent TDIs. Itch NRS (v2.0) modifications helped participants focus on their worst itching. Most participants preferred Skin Pain NRS v2.0b, which included skin pain descriptors. CONCLUSIONS: Itching and skin pain are the most important and relevant AD symptoms. The Itch NRS (v2.0) and Skin Pain NRS (v2.0b) appear to be appropriate endpoints for the assessment of itching and skin pain severity for clinical trials with adults and adolescents with AD.

Implementing patient-reported outcome measures in clinical practice: a companion guide to the ISOQOL user's guide.

PURPOSE: The use of patient-reported outcome (PRO) measures in clinical practice is increasing. Following the creation of a 'User's Guide to Implementing PRO Assessment in Clinical Practice' by the International Society for Quality of Life Research (ISOQOL), volunteers from ISOQOL sought to create a Companion Guide to assist health care providers with the scientific and practical considerations involved in implementing and using PRO measures in clinical care by using information from real-world case studies. This paper summarizes the key issues presented in the Companion Guide. METHODS: Ten respondents, who were members of the ISOQOL's CP-SIG and worked in various clinical areas, participated in a survey or telephone interview. Participants were from Canada (n = 2), Denmark (n = 1), England (n = 2), Holland (n = 1), and the United States (n = 4). RESULTS: Based on the information provided by respondents, a Companion Guide was produced, organized according to the nine questions presented in the User's Guide. An additional section for key take-home messages was also provided. This guide provides examples of issues and considerations related to the implementation of PRO measures in clinical practice. CONCLUSIONS: Respondents provided insight into their experiences and emphasized that PRO initiatives were likely to be more successful if there is purposeful, designed integration into clinical practice, meaningful substantive engagement with all stakeholders and access to necessary organizational resources. The ability to leverage existing technology as well as realistic and stakeholder consensus-driven expectations for planning and timing were also key to the successful implementation of PRO measures.

Experiences of registered nurses who supervise international nursing students in the clinical and classroom setting: an integrative literature review.

AIMS AND OBJECTIVES: To examine the literature reporting the experiences and perceptions of registered nurses who supervise international nursing students in the clinical and classroom setting. BACKGROUND: Nursing education relies on clinical experts to supervise students during classroom and clinical education, and the quality of that supervision has a significant impact on student development and learning. Global migration and internationalisation of nursing education have led to increasing numbers of registered nurses supervising international nursing students. However, a paucity of relevant literature limits our understanding of these experiences. DESIGN: An integrative literature review. METHODS: Comprehensive database searches of CINAHL, Informit, PubMed, Journals@Ovid, Findit@flinders and Medline were undertaken. Screening of 179 articles resulted in 10 included for review. Appraisal and analysis using Whittemore and Knafl's (Journal of Advanced Nursing, 52, 2005, 546) five stage integrative review recommendations was undertaken. RESULTS: This review highlighted some unique challenges for registered nurses supervising international nursing students. Identified issues were, a heightened sense of responsibility, additional pastoral care challenges, considerable time investments, communication challenges and cultural differences between teaching and learning styles. CONCLUSION: It is possible that these unique challenges could be minimised by implementing role preparation programmes specific to international nursing student supervision. Further research is needed to provide an in-depth exploration of current levels of preparation and support to make recommendations for future practice, education and policy development. RELEVANCE TO CLINICAL PRACTICE: An awareness of the specific cultural learning needs of international nursing students is an important first step to the provision of culturally competent supervision for this cohort of students. There is an urgent need for education and role preparation for all registered nurses supervising international nursing students, along with adequate recognition of the additional time required to effectively supervise these students.

Cone beam CT dose reduction in prostate radiotherapy using Likert scale methods.

OBJECTIVE: To use a Likert scale method to optimize image quality (IQ) for cone beam CT (CBCT) soft-tissue matching for image-guided radiotherapy of the prostate. METHODS: 23 males with local/locally advanced prostate cancer had the CBCT IQ assessed using a 4-point Likert scale (4 = excellent, no artefacts; 3 = good, few artefacts; 2 = poor, just able to match; 1 = unsatisfactory, not able to match) at three levels of exposure. The lateral separations of the subjects were also measured. The Friedman test and Wilcoxon signed-rank tests were used to determine if the IQ was associated with the exposure level. We used the point-biserial correlation and a χ(2) test to investigate the relationship between the separation and IQ. RESULTS: The Friedman test showed that the IQ was related to exposure (p = 2 × 10(-7)) and the Wilcoxon signed-rank test demonstrated that the IQ decreased as exposure decreased (all p-values <0.005). We did not find a correlation between the IQ and the separation (correlation coefficient 0.045), but for separations <35 cm, it was possible to use the lowest exposure parameters studied. CONCLUSION: We can reduce exposure factors to 80% of those supplied with the system without hindering the matching process for all patients. For patients with lateral separations <35 cm, the exposure factors can be reduced further to 64% of the original values. ADVANCES IN KNOWLEDGE: Likert scales are a useful tool for measuring IQ in the optimization of CBCT IQ for soft-tissue matching in radiotherapy image guidance applications.

Review of Penner's criteria for proficiency testing in cytopathology: implications for the redesign of the federally mandated proficiency testing in cytopathology.

Thirty-three years ago Penner advocated six criteria for the performance of proficiency testing in cytopathology (PTC). Since that time, several further requirements have been added by other authors. The present article critically evaluates and modifies the original criteria and adds two more principles, validity and reliability, that we recognize as crucially important in the performance of PTC. The revised criteria should be taken into consideration in the planned technical redesign of the nationwide PTC.

Cytopathology proficiency testing: where do we go from here?

With the recent introduction of nationwide proficiency testing in cytopathology (PTC), reconsideration of several aspects of this controversial quality assurance method becomes justified. This paper discusses various merits and demerits of the PTC system currently prescribed by federal regulations, points out perceived deficiencies, and suggests methods for improvement.