Cost-effectiveness analysis of a multiplex lateral flow rapid diagnostic test for acute non-malarial febrile illness in rural Cambodia and Bangladesh

Background

Multiplex lateral flow rapid diagnostic tests (LF-RDTs) may aid management of patients with acute non-malarial febrile illness (NMFI) in rural south and southeast Asia. We aimed to evaluate the cost-effectiveness in Cambodia and Bangladesh of a putative, as-yet-undeveloped LF-RDT capable of diagnosing enteric fever and dengue, as well as measuring C-reactive protein (CRP) to guide antibiotic prescription, in primary care patients with acute NMFI.

Methods

A country-specific decision tree model-based cost-effectiveness analysis was conducted from a health system plus limited societal perspective considering the cost of antimicrobial resistance. Parameters were based on data from a large observational study on the regional epidemiology of acute febrile illness, published studies, and procurement price lists. Costs were expressed in US$ (value in 2022), and cost-effectiveness evaluated by comparing incremental cost-effectiveness ratios with conservative opportunity cost-based willingness-to-pay thresholds and the more widely used threshold of per capita gross domestic product (GDP).

Findings

Compared to standard of care, LF-RDT-augmented clinical assessment was dominant in Cambodia, being more effective and cost-saving. The cost per disability-adjusted life year (DALY) averted in Bangladesh was US$482, slightly above the conservative opportunity cost-based willingness-to-pay threshold of US$388 and considerably lower than the GDP-based threshold of US$2687. The intervention remained dominant in Cambodia and well below the GDP-based threshold in Bangladesh when antimicrobial resistance costs were disregarded.

Interpretation

These findings provide guidance for academic, industry, and policymaker stakeholders involved in acute NMFI diagnostics. While definitive conclusions cannot be made in the absence of established thresholds, our results suggest that similar results are highly likely in some target settings and possible in others.

Funding

Wellcome Trust, UK Government, Royal Australasian College of Physicians, and Rotary Foundation.

A systematic literature review of economic evaluation studies of interventions impacting antimicrobial resistance

BACKGROUND

Antimicrobial resistance (AMR) is accelerated by widespread and inappropriate use of antimicrobials. Many countries, including those in low- and middle- income contexts, have started implementing interventions to tackle AMR. However, for many interventions there is little or no economic evidence with respect to their cost-effectiveness. To help better understand the scale of this evidence gap, we conducted a systematic literature review to provide a comprehensive summary on the value for money of different interventions affecting AMR.

METHODS

A systematic literature review was conducted of economic evaluations on interventions addressing AMR. a narrative synthesis of findings was produced. Systematic searches for relevant studies were performed across relevant databases and grey literature sources such as unpublished studies, reports, and other relevant documents. All identified economic evaluation studies were included provided that they reported an economic outcome and stated that the analysed intervention aimed to affect AMR or antimicrobial use in the abstract. Studies that reported clinical endpoints alone were excluded. Selection for final inclusion and data extraction was performed by two independent reviewers. A quality assessment of the evidence used in the included studies was also conducted.

RESULTS

28,597 articles were screened and 35 articles were identified that satisfied the inclusion criteria. The review attempted to answer the following questions: (1) What interventions to address AMR have been the subject of an economic evaluation? (2) In what types of setting (e.g. high-income, low-income, regions etc.) have these economic evaluations been focused? (3) Which interventions have been estimated to be cost-effective, and has this result been replicated in other settings/contexts? (4) What economic evaluation methods or techniques have been used to evaluate these interventions? (5) What kind and quality of data has been used in conducting economic evaluations for these interventions?

DISCUSSION

The review is one of the first of its kind, and the most recent, to systematically review the literature on the cost-effectiveness of AMR interventions. This review addresses an important evidence gap in the economics of AMR and can assist AMR researchers' understanding of the state of the economic evaluation literature, and therefore inform future research. Systematic review registration PROSPERO (CRD42020190310).

How to model the impact of vaccines for policymaking when the characteristics are uncertain: A case study in Thailand prior to the vaccine rollout during the COVID-19 pandemic

Thailand faced a dilemma of which groups to prioritise with a limited first tranche of COVID-19 vaccinations in early 2021, at a time when there was low incidence and low mortality in the country. A mathematical modelling analysis was performed to compare the potential short-term impact of allocating the available doses to either the high severity group (over 65-year-olds) or the high transmission group (aged 20-39). At the time of the analysis, there was uncertainty about the precise characteristics of the vaccines available, in terms of their potential impact on transmission and reductions to the severity of infection. As such, a range of vaccine characteristic scenarios, with differing levels of severity and transmission reductions were explored. Using the evidence available at the time regarding severity reduction of infection due to the vaccines, the model suggested that vaccinating high severity group should be the priority if reductions in deaths is the priority. Vaccinating this group was found to have a direct impact on reducing the number of deaths, while the incidence and hospitalisations remained unchanged. However, the model found that vaccinating the high transmission group with a vaccine with sufficiently high protection against infection (more than 70%) could provide enough herd effects to delay the expected epidemic peak, resulting in both case and death reductions in both target groups. The model explored a 12-month time horizon. These analyses helped to inform the vaccination strategy in Thailand throughout 2021 and can inform future modelling studies for policymaking when the characteristics of vaccines are uncertain.

Avoiding health technology assessment: a global survey of reasons for not using health technology assessment in decision making

INTRODUCTION

Despite the documented benefits of using health technology assessments (HTA) to inform resource allocation in health care systems, HTA remains underused, especially in low- and middle-income countries. A survey of global health practitioners was conducted to reveal the top reasons ("excuses") that they had heard from colleagues, policymakers or other stakeholders for not using HTA in their settings.

METHODS

There were 193 respondents to the survey. Most responses were from individuals in research organisations (37%), ministries of health (27%) and other government agencies (14%). Participants came from Southeast Asia (40%), the Western Pacific (30%), Africa (15%), Europe (7%), the Americas (7%) and the Eastern Mediterranean region (2%).

RESULTS

The top five reasons encountered by respondents related to lack of data, lack of technical skills for HTA, the technocratic nature of the work, the lack of explicit decision rules and the perception that HTA puts a "price on life".

CONCLUSIONS

This study aimed to understand and address the top reasons for not using HTA. They fall into three categories: (1) misconceptions about HTA; (2) feasibility issues; and (3) values, attitudes and politics. Previous literature has shown that these reasons can be addressed when identified, and even imperfect HTA analyses can provide useful information to a decision-maker.

A protocol for a systematic literature review of economic evaluation studies of interventions to address antimicrobial resistance

BACKGROUND

Antimicrobial resistance (AMR) is accelerated by the widespread and often indiscriminate use of antimicrobials in humans, animals, and the environment. In 2015, the World Health Organization recognised AMR as one of the top ten global health threats, due to its potential to neutralise humanity's advancements in western medicine by enabling the emergence of new strains of existing pathogens, many of which have no available treatments. Over the past decade, several countries, including those in low- and middle-income contexts, have started implementing interventions to tackle AMR. However, economic evidence regarding the cost-effectiveness of these interventions remains weak. To address this evidence gap, we will conduct a systematic literature review to provide a comprehensive summary on the value for money of different AMR interventions.

METHODS

We aim to conduct a systematic literature review of all available economic evaluations on interventions addressing AMR and will provide a narrative synthesis of our findings. Systematic searches for relevant studies will be performed across all suitable databases as well as in grey literature sources such as unpublished studies, reports, and other relevant documents. All economic evaluation studies will be included as long as they report an economic outcome and have stated that the analysed intervention will reduce antimicrobial resistance or antimicrobial use in the abstract. Those studies reporting clinical endpoints alone will be excluded. Selection for final inclusion and data extraction will be performed by two independent reviewers.

DISCUSSION

The review will be one of the first of its kind, and the most recent, to systematically review literature on the cost-effectiveness of AMR interventions, an important evidence gap in the economics of AMR. The findings will enable policy and decision-makers, particularly in resource-constrained settings, to better use available resources when selecting interventions to address AMR burdens, SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42020190310.

Avoiding Trouble Ahead: Lessons Learned and Suggestions for Economic Evaluations of COVID-19 Vaccines

With vaccines for coronavirus disease 2019 (COVID-19) being introduced in countries across the world, policy makers are facing many practical considerations about how best to implement a vaccination programme. The supply of vaccines is insufficient for the global population, so decisions must be made as to which groups are prioritised for any vaccination and when. Furthermore, the aims of vaccination programmes will differ between countries, with some prioritising economic benefits that could stem from the relaxation of non-pharmaceutical interventions and others seeking simply to reduce the number of COVID-19 cases or deaths. This paper aims to share the experiences and lessons learned from conducting economic evaluations in Singapore and Thailand on hypothetical COVID-19 vaccines to provide a basis for other countries to develop their own contextualised economic evaluations, with particular focus on the key uncertainties, technical challenges, and characteristics that modellers should consider in partnership with key stakeholders. Which vaccines, vaccination strategies, and policy responses are most economically beneficial remains uncertain. It is therefore important for all governments to conduct their own analyses to inform local policy responses to COVID-19, including the implementation of COVID-19 vaccines in both the short and the long run. It is essential that such studies are designed, and ideally conducted, before vaccines are introduced so that policy decisions and implementation procedures are not delayed.

Hepatitis C prevalences in the psychiatric setting: Cost-effectiveness of scaling-up screening and direct-acting antiviral therapy

BACKGROUND & AIMS

Patients hospitalised because of mental illness often have risk factors for contracting HCV. Scaling-up HCV screening for all psychiatric inpatients as a case-detection strategy for viral elimination is underexplored. This study aimed to evaluate the cost-effectiveness of scaling-up HCV screening and treatment for psychiatry hospital admissions in Switzerland vs. the current standard-of-care risk-based approach, where only those with a history of substance misuse disorder are offered testing.

METHODS

HCV prevalence by history of substance misuse disorder was analysed in medical records from inpatient admissions to a Swiss psychiatry department. Cost-effectiveness was analysed from a healthcare provider perspective through a decision-tree screening model, using these HCV prevalence data. Model and parameter uncertainty were assessed using deterministic and probabilistic sensitivity analyses.

RESULTS

Prevalence of HCV in psychiatry inpatients with a history of substance misuse disorder (n = 1,013) was 25.7%, compared with 3.5% among the remaining inpatients (n = 3,535). Scaling up HCV screening and treatment for all psychiatry admissions was cost-effective vs. the risk-based approach, with an incremental cost-effectiveness ratio of US$9,188 per quality-adjusted life-year gained. The incremental cost-effectiveness ratio remained cost-effective considering a HCV prevalence as low as 0.07%. The population-level net monetary benefit of the generalised screening approach was US$435,156,348, with 917 additional patients per year detected and treated at a cost of US$3,294 per person (vs. US$2,122 under risk-based screening).

CONCLUSIONS

Scaling up HCV screening and treatment at diagnosis with all-oral, interferon-free regimens as a generalised approach for psychiatric admissions was cost-effective and could support reaching World Health Organization targets for HCV elimination by 2030.

LAY SUMMARY

Patients hospitalised because of mental illness often have risk factors for HCV. We found that testing all psychiatry patients in hospital for HCV was cost-effective compared with testing only patients who have a history of substance misuse. Scaling up HCV testing and treatment could help to wipe out HCV.

Abstract PD9-03: The genomic landscape of de novo metastatic breast cancer (MBC)

Background: Approximately 5-10% of newly diagnosed breast cancers (BC) are de novo MBC, which means that metastatic disease was identified at the time of initial diagnosis. Patients with de novo MBC are underrepresented in currently available genomic studies. In The Cancer Genome Atlas (TCGA) dataset, only 15 out of ˜980 BC patients can be classified as having de novo MBC. The objective of this study is to analyze the genomic landscape of de novo MBC and to study the genomic differences of this cohort with early stage BC. To enhance our ability to study de novo MBC, we utilized data from the Metastatic Breast Cancer Project (MBCproject), a patient-partnered research project that aims to generate a large public database of clinical, genomic, and patient reported data (PRD) from patients with MBC.

Methods: We defined de novo MBC as patients diagnosed with metastatic disease less than 4 months after their initial diagnosis with BC.Out of 127 patients in the MBCproject with publicly released whole exome sequencing (WES) data, we identified 33 patients with de novo MBC. We combined this data with 15 de novo MBC patients in TCGA. For patients with de novo MBC with multiple tumor biopsies available, we used WES from breast biopsies to enable appropriate comparison to the early stage biopsies. Somatic mutations were evaluated and significantly recurring genes were identified using MutSig2CV. We compared the mutations found in the de novo cohort with early stage tumors. 10 patients in the de novo MBC cohort had paired simultaneous primary and metastatic biopsies; genomic alterations in these samples were compared. Finally, we used RNA sequencing data to compare cytolytic signatures among the de novo and early stage biopsies.

Results: Among the 48 patients analyzed the receptor subtype distribution was: HR+/HER2-(23), HR+/HER2+(13), HR-/HER2+(2), HR-/HER2-(3), HR+/HER2 unknown(5), and HR-/HER2 unknown(2). Histology subtype distribution was as follows: IDC(39), MDLC(6), ILC(2) and Other (1). Significantly recurrent genes in the de novo MBC cohort (q<0.1) included TP53(27%), PIK3CA(30%), CDH1(8%) and MAP3K1(11%). Mutations in PTEN, EGFR, and MDM4 were significantly enriched (p <0.05) in the de novo cohort when compared to early stage BC Evolutionary analysis of paired primary and metastatic biopsies for de novo MBC patients demonstrated the presence of shared clonal mutations, indicating that these were highly evolutionarily related. RNA-seq immune cytolytic signature was downregulated in de novo MBC as compared to early stage BC (p <0.2).

Gene% Mutation Rate in De Novo MBC (N=48)% Mutation rate in Early Stage BC (N= 997)p-valuePTEN10.403.510.0324EGFR6.250.500.00435MDM44.170.300.0189

Conclusions: Our initial results highlight genomic differences between de novo MBC and early stage BC, including increased frequency of PTEN, EGFR, and MDM4 mutations. Enrichment of PTEN mutations (implicated in tumor immune surveillance), and downregulation of cytolytic signature potentially suggests that de novo MBC may have immunosuppressive tumor microenvironment. To date, ˜1200 patients with self-reported de novo MBC have registered for the MBCproject. We anticipate that additional study of genomic and clinical data from these patients will greatly improve our understanding of de novo MBC.

Citation Format: Jain E, Kim D, Buendia JB, Cohen O, Sousa RB, Anastasio E, Dunphy M, McGillicuddy M, Stoddard R, Balch S, Thomas B, Di Lascio S, Tomson BN, Nguyen C, Painter C, Wagle N. The genomic landscape of de novo metastatic breast cancer (MBC) [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr PD9-03.

Student Research Award 1999: comparative contrast of voice measurements

Currently, a variety of objective and subjective measures are available to describe voice and voice function. Despite these various tools, there is no standard measure of voice function that incorporates both objective and subjective measures. The goal of this research was to study the relationship between objective, subjective, and patient-based measures of voice function. Objective voice function was measured with 4 laboratory-based parameters (subglottic pressure, airflow at the lips, maximum phonation time, and vocal efficiency), subjective function with the GRBAS (grade, rough, breathy, asthenic, strained) scale, and patient-based function according to an overall global rating of quality. The objective and subjective measures were significantly related to each other (P < 0.05); the objective and patient-based measures were also related (P = 0.019), but the subjective and patient-based measures were not related. We demonstrate a significant relationship between some but not all measures of voice function. We believe that subjective measures provide additional valuable information not obtained from objective measures alone.

Assessment of two objective voice function indices

In the care of patients with voice disorders, physicians, speech pathologists, and other health care professionals routinely make diagnoses, recommend treatment, and evaluate outcomes. Although objective and subjective measures exist, unfortunately, there is no widely accepted, valid method for classifying voice disorders and assessing outcome after voice treatment. In the present research, the relationship between two previously created multivariate objective voice function indices, the weighted odds ratio index and the multivariate logistic regression index, and subjective assessment of voice function was evaluated. Twenty-three adult patients presenting to a speech science laboratory for evaluation of voice disorders were studied in this prospective observational study together with 12 normal volunteers as controls. Vocal function was measured on 14 different parameters with a protocol that included a multichannel input for simultaneous assessment of acoustic and physiological parameters. Each patient was recorded reading the standard passage "The North Wind and the Sun," and recordings were then evaluated by the GRBAS scale. Overall, there was a statistically significant relationship between the weighted odds ratio index and multivariate logistic regression index and mean GRBAS scores. This research demonstrates that the voice function values calculated from two different multivariate objective voice function indices are significantly associated with subjective voice assessments. These multivariate objective voice indices may be appropriate for use in clinical trials and outcomes research on treatment effectiveness for voice disorders.

Multivariate analysis of objective vocal function

No standard and valid multidimensional index of objective voice function has been developed that integrates the information generated from the multiple objective parameters of voice function. The goals of this research were 1) to identify important objective voice parameters and 2) to create a multidimensional voice function index by combining relevant parameters. We evaluated 97 dysphonic patients and 35 normal volunteers on 14 objective voice parameters. Three multidimensional voice indices were created and evaluated: 1) nonweighted univariate index, 2) weighted odds ratio index, and 3) weighted multivariate regression index. The univariate index required all 14 parameters, while the odds ratio and logistic regression models required only 4 parameters (frequency range, airflow at lips, maximum phonation time, and subglottic pressure). The chi2 values for the 3 models were 37.8, 37.6, and 46.0, respectively. All 3 indices were able to satisfactorily classify voice function as normal or abnormal. However, the regression index performed best.

Characterization and chromosomal localization of PTPRO, a novel receptor protein tyrosine phosphatase, expressed in hematopoietic stem cells

Hematopoietic stem cells (HSCs) support blood cells throughout life by utilizing their self-renewing and multilineage differentiating capabilities. Hematopoietic growth factors mediate their effects on stem cells by the tyrosine phosphorylation of proteins. Regulation of tyrosine phosphorylation is partially mediated by protein tyrosine phosphatases (PTPases). A possible mechanism by which hematopoietic stem cells maintain their self-renewing capacity and undifferentiated state is by controlling the balanced and opposing actions of protein tyrosine kinases (PTKs), receptors for growth factors, and PTPases. We have characterized the expression of PTPases in 5-fluorouracil (5-FU)-treated murine bone marrow cells, which represent a very primitive population of progenitors enriched for reconstituting stem cells, by using a consensus polymerase chain reaction (PCR) method. Several PTPases were expressed abundantly in the 5-FU-treated bone marrow stem cells. A novel PTP, termed protein tyrosine phosphatase receptor omicron (PTPRO), which is related to the homotypically adhering kappa, mu and PCP-2 receptor-type tyrosine phosphatases, was identified and characterized. We have cloned the murine and full-length human PTPRO cDNAs which share 89% homology, indicating that PTPRO is highly conserved between these species. The human PTPRO cDNA clone encodes a polypeptide of 1439 amino acids (aa) and has a calculated molecular mass of approximately 162 kDa. PTPRO consists of an extracellular segment containing a MAM domain, an immunoglobulin (Ig) domain, four fibronectin-type III (FN-III) repeats, a transmembrane segment, and two tandem intracellular PTP domains. The human PTPRO gene was assigned to human chromosome 1p35-pter using Southern blot analyses of genomic DNAs from rodent/human somatic hybrid cell lines containing human chromosome 1 or the p35-pter region of the chromosome. The mouse Ptpro gene was mapped to chromosome 4, closely linked to D4Mit16 and Elp1 (elliptocytosis-1), by using genomic DNAs from a (C57BL/6J x Mus spretus)F1 x Mus spretus backcross. In fetal tissues, PTPRO expression was observed in the brain and lung, whereas lower levels were observed in the kidney. In adult tissues, PTPRO was less restricted and was observed in the lung, heart, skeletal muscle, prostate, testis, and in various areas of the brain, indicating that PTPRO expression is developmentally regulated. Expression of PTPRO was also observed in human CD34+ bone marrow cells and 5-FU-treated murine primitive stem cells. These results suggest a potential role for PTPRO in stem cell adhesion and in mediating homophilic cell-cell interactions in other cell types.

Semi-automated voice evaluation

This report describes a voice evaluation procedure that in some way parallels the audiologic tests used for hearing and has multiple uses both clinically and in research. It uses a simultaneous eight-channel input, is not difficult to use, requiring between 12 and 25 minutes to administer, and provides the physician with a printout in standardized form before the patient leaves the room. This three-page report includes 15 abstracted or calculated values, normal ranges by sex for each value, notes that draw attention to deviations from the normal, a summary profile, a graphic representation of the evaluation, and raw data waveforms.

Laryngeal configuration of 99 dysphonic patients

The aim of this investigation was to study a wide range of dysphonic patients and determine the best matches among the laryngeal configurations on phonation for each patient and those previously established for control data, which were obtained from a professional voice user producing the whole range of voice qualities. Ninety-nine patients were selected and laryngeal photographs were produced for each patient. Fifteen laryngeal parameters were quantified and normalized. The data were sorted, scalar values assigned and a measure of similarity between configurations applied. The best, second-best, third-best and worst matches between each patient separately and the control data were then examined. Although 41% of the patients did not have particularly unusual configurations, 59% exhibited a narrowing of the laryngeal vestibule caused by epiglottic retraction, cuneiform fronting and/or false fold adduction. This suggests that clinical reports for patients with dysphonia should contain information not only on any lesions present but also on laryngeal configurations and, in particular, vestibular narrowing.

The laryngeal vestibule, voice quality and paralinguistic markers

The laryngeal component of voice quality markers has been quantified in the present study, suggesting that the laryngeal vestibule and lower pharynx play an important role in voice quality. Findings also show that voice quality can be partly described in terms of laryngeal configurations and that a knowledge of these configurations may be useful to the laryngologist, speech pathologist and singer. Twenty-five voice qualities were videorecorded, using a nasal fiberscope. Still photographs were taken for each voice quality and distance measurements made on each one for 15 laryngeal parameters. The raw data were normalized, sorted from high to low, turned into scalar values and processed to establish which parameters exhibited similar functions, which photographs were essentially identical, and in what respect any two photographs were different. Each voice quality was seen to be associated with a different, describable and quantifiable laryngeal configuration.

Electroglottogram waveform types of untrained speakers

Electroglottography is a useful, non-invasive technique that can assist in the assessment of vocal fold dysfunction. However, if it is to become a useful clinical tool, there is a need for normative studies of the electroglottogram waveform types that characterize different groups of speakers. This report compares the electroglottogram waveform types characterizing one trained professional voice user phonating in 15 experimental sessions under various fundamental frequencies, intensities and voice qualities with those obtained from 52 untrained non-professional speakers.

The incidence of voice disorders

This report summarizes the log book for patients with voice disorders treated at Washington University in St. Louis between 1984 and 1988. Our experience with these 764 patients is expressed as the number of visits for each problem type.

Clinical and histopathological considerations for the diagnosis and treatment of verrucous carcinoma of the larynx

Verrucous carcinoma of the larynx is quite distinct from well-differentiated squamous cell carcinoma has a characteristic morphology and specific clinical behavior. It accounts for approximately 1%-2% of all laryngeal carcinomas. However, difficulties are encountered clinically in separating verrucous carcinomas from keratoses, verruca vulgaris and squamous cell carcinomas with a verrucous appearance. Between 1962 and 1982, 1504 patients with squamous cell carcinomas of the larynx were diagnosed and treated by staff physicians in the Department of Otolaryngology--Head and Neck Surgery, Washington University in St. Louis. Fifteen of these patients (1%) had verrucous carcinomas. These cases were studied in order to clarify any diagnostic problems, trace the biologic behavior of the tumors and report the results of the treatment used. Of these 15 patients, we were able to follow up 8. The latter had been treated only with surgery and none of them had received radiotherapy. One death occurred, but the patient died of other causes and remained free of cancer. Reports in the literature describe a high rate of recurrence of verrucous carcinomas following radiotherapy with occasional anaplastic transformation of tumors. No patients in our series developed a metastasis in the neck, indicating that neck dissection is not justified for patients with these neoplasms even though clinically enlarged neck nodes may be present.

The transformation of laryngeal keratosis into invasive carcinoma

Although 93.0% to 97.0% of all laryngeal carcinomas are diagnosed on the first biopsy, 3.0% to 6.7% of them occur in patients who have what is initially diagnosed as "laryngeal keratosis." To study this phenomenon, we examined data from 1,019 patients with laryngeal keratosis seen between 1962 and 1981. Eleven patients with keratosis and initially undetected cancer at different laryngeal sites were excluded, as were 87 outside referrals for whom no records were available beyond the histologic report. The remaining 921 patients were classified on the basis of the initial histologic findings into groups comprising 604 patients with keratosis without atypia (group 1), 204 patients with mild atypia (group 2), 23 patients with moderate atypia (group 3), and 90 patients with severe atypia (group 4). All 921 were followed for from 5 to 25 years. Invasive carcinoma of the larynx developed in 18 patients from group 1 (3.0%), 15 from group 2 (7.4%), four from group 3 (17.4%), and 25 from group 4 (27.8%). Fifty-seven patients (91.9%) developed invasive carcinoma after less than 10 years but only five (8.1%) did so after 10 years or more.

Electroglottogram waveform types

Electroglottography is a useful, non-invasive technique that can assist in the assessment of vocal fold dysfunction. However, if it is to become a useful clinical tool, there is a need for normative studies of the electroglottogram waveform types that characterize trained professional voice users, untrained non-professional speakers and patients with voice disorders and for a way of quantifying and objectively comparing similarities and differences. This report describes our methodology and an investigation into the waveform types characterizing one trained professional voice user phonating in 15 experimental sessions under various fundamental frequency, intensity and voice quality conditions. A number of strong tendencies were noted. In normal voice the lower frequencies and intensities represent one pole of a scale of a mode of phonation, while the higher frequencies and intensities depict the other pole. In these studies breathy voice data overlapped the lower end of the scale and tense voice data overlapped the upper end.

Human speech development for an implantable artificial larynx

An electromagnetic artificial larynx was implanted in two volunteer laryngectomees. Both patients were able to communicate well, but the voice quality still needed improving. Therefore, in this investigation, listener judgments were obtained of 22 different sound sources with a view to incorporating the preferred speech sound in a new version of the device. Electroglottograms were used as sound sources in a speech synthesizer and sentences were produced with different voice qualities for judgmental tests. The results of the listening tests showed a distinct preference for waveforms corresponding to a long completely open phase, a very brief completely closed phase, and an abrupt closing gesture. The optimum acoustic characteristics for the device will be used by electrical engineers to manufacture a new version of the artificial larynx with an improved voice quality.

On buying a telescope for videolaryngoscopy

The purpose of this article is to compare aspects of the performance of three widely-used rigid laryngoscopy telescopes. The Nagashima SFT-I, Wolf 4450.57, and Karl Storz 8702 D were used with a JVC GX-N8U camera and Panasonic PV 8600 VCR to make recordings of a one-tenth-inch grid at various distances between the lens and the grid and at two telescope holding angles. Measurements were made of the anteroposterior and mediolateral viewing fields at all distances and holding angles on maximum and minimum zoom. The telescopes were compared for viewing field, lens angle effects, holding angle effects, plane distortion effects, effects due to lens distance, color, edge definition, focus control, light source compatibility, stroboscopic use, cross-sectional diameter, fogging, and cost. An overview enables laryngologists to assess their needs before buying.

The laryngeal vestibule and voice quality

Most of the literature on voice quality focuses on the vocal folds while six other gestures involving the laryngeal entry and epilaryngeal structures are largely ignored. Whole organ tracer series histograms of the larynx are examined and suggestions are made as to which muscles and/or forces might cause these gestures. An examination of photographs of the larynx indicates that the latter must be described in three dimensions: medio-lateral, antero-posterior, and vestibule cross-sectional area. The article is aimed at laryngologists in general, not surgeons in particular, and has implications for laryngology (being a putative model of diagnostic procedures), physiology (what forces create epilaryngeal configurations?), neuroscience (does the motor cortex control single muscles or whole gestures?), speech pathology (what is the ragbag called "hypertenseness"?), linguistics (how is one to describe lower pharynx phenomena?) and paralinguistics (what is the extrasystemic laryngeal component of voice quality?).

Shared idiotypes and restricted immunoglobulin variable region heavy chain genes characterize murine autoantibodies of various specificities

The study of the Ig variable region heavy chain (VH) genes used to encode antibodies specific for self-epitopes from murine hybridomas showed that three VH families are primarily utilized: VH J558, the largest family, and VH QPC52 and VH 7183, the families most proximal to the Ig joining region heavy chain genes. These monoclonal autoantibodies express cross-reactive idiotopes shared by rheumatoid factors and antibodies specific for Sm. The expression of these idiotypes is independent of major histocompatibility complex and Ig constant region heavy chain haplotypes, self-antigen specificity, and even the VH gene family utilized. Though the experiments described here are limited to murine autoantibodies, similarities exist between murine and human autoimmune diseases. Studies that aim to investigate the relationship between VH gene expression and the presence of cross-reactive idiotypes among human autoantibodies should enable us to better understand the mechanisms of autoimmunity and self-tolerance.