Anticipating PTSD in severe COVID survivors: the case for screen-and-treat.

Based on research from previous pandemics, studies of critical care survivors, and emerging COVID-19 data, we estimate that up to 30% of survivors of severe COVID will develop PTSD. PTSD is frequently undetected across primary and secondary care settings and the psychological needs of survivors may be overshadowed by a focus on physical recovery. Delayed PTSD diagnosis is associated with poor outcomes. There is a clear case for survivors of severe COVID to be systematically screened for PTSD, and those that develop PTSD should receive timely access to evidence-based treatment for PTSD and other mental health problems by multidisciplinary teams.

Basados en la investigación de pandemias previas, los estudios de los sobrevivientes a cuidados críticos, y los datos emergentes de COVID-19, estimamos que hasta un 30% de los sobrevivientes del COVID grave desarrollarán TEPT. El TEPT es frecuentemente subdetectado en los servicios de salud primarios y secundarios y las necesidades psicológicas de los sobrevivientes puede verse eclipsadas por un enfoque en la recuperación física. El diagnóstico tardío de TEPT se asocia con pobres resultados. Existe un caso claro para que los sobrevivientes del COVID grave sean evaluados sistemáticamente para detectar el TEPT, y aquellos que desarrollan un TEPT deben tener acceso oportuno a tratamientos basados en la evidencia para el TEPT y para otros problemas de salud mental por equipos multidisciplinarios.

The prevalence of common and stress-related mental health disorders in healthcare workers based in pandemic-affected hospitals: a rapid systematic review and meta-analysis.

Background: Healthcare workers (HCWs) are considered at elevated risk of experiencing mental health disorders in working with patients with COVID-19. Objective: To estimate the prevalence of common mental health disorders in HCWs based in hospitals where pandemic-affected patients were treated. Method: Databases were searched for studies published before 30 March 2020. Quantitative synthesis was used to obtain estimates of the prevalence of mental health disorders in four time windows, determined a priori (the acute phase, i.e. during and up to 1.5 months post-pandemic; 1.5-5.9 months; 6-11.9 months; 12 months and later). Results: Nineteen studies met the review criteria. They predominantly addressed the acute phase of the SARS outbreak in Asia. The most studied outcomes were clinically significant post-traumatic stress symptoms (PTSS) and general psychiatric caseness. For clinically significant PTSS in the acute phase, the prevalence estimate was 23.4% (95% CI 16.3, 31.2; N = 4147; I2 = 96.2%); in the 12 months plus window, the estimate was 11.9% (8.4, 15.8; N = 1136; I2 = 74.3%). For general psychiatric caseness, prevalence estimates were acute phase, 34.1% (18.7, 51.4; N = 3971; I2 = 99.1%); 6-12 months, 17.9% (13.1, 23.2; N = 223; I2 = 0.0%); 12 months plus, 29.3% (6.0, 61.0; N = 710; I2 = 97.8%). No differences between doctors and nurses with respective to PTSS and general psychiatric caseness were apparent in the acute phase. Conclusions: Mental health disorders are particularly common in HCWs working with pandemic-afflicted patients immediately following a pandemic, but the course of disorders following this period is poorly understood. There was considerable heterogeneity between studies, likely linked to methodological differences. More extended follow up of HCWs is needed.

Antecedentes: Se considera que los trabajadores de la salud (TS) tienen un riesgo elevado de experimentar trastornos de salud mental al trabajar con pacientes con COVID-19.Objetivo: Estimar la prevalencia de trastornos de salud mental comunes en los TS de los hospitales donde se trataron a pacientes afectados por una pandemia.Método: Se realizaron búsquedas en las bases de datos para estudios publicados antes del 30 de marzo de 2020. Se utilizó una síntesis cuantitativa para obtener estimaciones de la prevalencia de trastornos de salud mental en cuatro ventanas de tiempo, determinadas a priori (la fase aguda, es decir, durante y hasta 1,5 meses después de la pandemia; 1.5-5.9 meses; 6-11.9 meses; y después de 12 meses).Resultados: Diecinueve estudios cumplieron los criterios de esta revisión. Principalmente abordaron la fase aguda del brote de SARS en Asia. Los resultados más estudiados fueron los síntomas de estrés postraumático clínicamente significativos (SEPT) y casuística psiquiátrica general. Para los SEPT clínicamente significativo en la fase aguda, la estimación de prevalencia fue del 23,4% (IC del 95%: 16,3, 31,2; N = 4147; I2 = 96,2%); en los 12 meses adicionales, la estimación fue del 11,9% (8,4, 15,8; N = 1136; I2 = 74,3%). Para los casos de psiquiatría general, las estimaciones de prevalencia fueron: fase aguda, 34.1% (18.7, 51.4; N = 3971; I2 = 99.1%); 6-12 meses, 17.9% (13.1, 23.2; N = 223; I2 = 0.0%); después de 12 meses, 29.3% (6.0, 61.0; N = 710; I2 = 97.8%). No se observaron diferencias entre los médicos y las enfermeras con SEPT y casuística psiquiátrica general en la fase aguda.Conclusiones: Los trastornos de salud mental son particularmente comunes en los TS que trabajan con pacientes afectados inmediatamente después de la pandemia, pero el curso de los trastornos después de este período es poco conocido. Hubo una considerable heterogeneidad entre los estudios, probablemente vinculada a diferencias metodológicas. Se necesita un seguimiento más extenso de los TS.

An analysis of network brokerage and geographic location in fifteenth-century AD Northern Iroquoia.

Iroquoian villagers living in present-day Jefferson County, New York, at the headwaters of the St. Lawrence River and the east shore of Lake Ontario, played important roles in regional interactions during the fifteenth century AD, as brokers linking populations on the north shore of Lake Ontario with populations in eastern New York. This study employs a social network analysis and least cost path analysis to assess the degree to which geographical location may have facilitated the brokerage positions of site clusters within pan-Iroquoian social networks. The results indicate that location was a significant factor in determining brokerage. In the sixteenth century AD, when Jefferson County was abandoned, measurable increases in social distance between other Iroquoian populations obtained. These results add to our understandings of the dynamic social landscape of fifteenth and sixteenth century AD northern Iroquoia, complementing recent analyses elsewhere of the roles played in regional interaction networks by populations located along geopolitical frontiers.

Radiocarbon re-dating of contact-era Iroquoian history in northeastern North America.

A time frame for late Iroquoian prehistory is firmly established on the basis of the presence/absence of European trade goods and other archeological indicators. However, independent dating evidence is lacking. We use 86 radiocarbon measurements to test and (re)define existing chronological understanding. Warminster, often associated with Cahiagué visited by S. de Champlain in 1615-1616 CE, yields a compatible radiocarbon-based age. However, a well-known late prehistoric site sequence in southern Ontario, Draper-Spang-Mantle, usually dated ~1450-1550, yields much later radiocarbon-based dates of ~1530-1615. The revised time frame dramatically rewrites 16th-century contact-era history in this region. Key processes of violent conflict, community coalescence, and the introduction of European goods all happened much later and more rapidly than previously assumed. Our results suggest the need to reconsider current understandings of contact-era dynamics across northeastern North America.

Effects of population dispersal on regional signaling networks: An example from northern Iroquoia.

The dispersal of Iroquoian groups from St. Lawrence River valley during the 15th and 16th centuries A.D. has been a source of archaeological inquiry for decades. Social network analysis presented here indicates that sites from Jefferson County, New York at the head of the St. Lawrence River controlled interactions within regional social signaling networks during the 15th century A.D. Measures indicate that Jefferson County sites were in brokerage liaison positions between sites in New York and Ontario. In the network for the subsequent century, to which no Jefferson County sites are assigned, no single group took the place of Jefferson County in controlling network flow. The dispersal of Jefferson County populations effectively ended this brokerage function concomitant with the emergence of the nascent Huron-Wendat and Iroquois confederacies and may have contributed to the escalation of conflict between these entities. These results add to a growing literature on the use of network analyses with archaeological data and contribute new insights into processes of population relocation and geopolitical realignment, as well as the role of borderlands and frontiers in nonstate societies.

A Systematic Review and Meta-Analysis of e-Mental Health Interventions to Treat Symptoms of Posttraumatic Stress.

BACKGROUND: Posttraumatic stress disorder (PTSD) is a stress disorder characterized by unwanted intrusive re-experiencing of an acutely distressing, often life-threatening, event, combined with symptoms of hyperarousal, avoidance, as well as negative thoughts and feelings. Evidence-based psychological interventions have been developed to treat these symptoms and reduce distress, the majority of which were designed to be delivered face-to-face with trained therapists. However, new developments in the use of technology to supplement and extend health care have led to the creation of e-Mental Health interventions. OBJECTIVE: Our aim was to assess the scope and efficacy of e-Mental Health interventions to treat symptoms of PTSD. METHODS: The following databases were systematically searched to identify randomized controlled trials of e-Mental Health interventions to treat symptoms of PTSD as measured by standardized and validated scales: the Cochrane Library, MEDLINE, EMBASE, and PsycINFO (in March 2015 and repeated in November 2016). RESULTS: A total of 39 studies were found during the systematic review, and 33 (N=3832) were eligible for meta-analysis. The results of the primary meta-analysis revealed a significant improvement in PTSD symptoms, in favor of the active intervention group (standardized mean difference=-0.35, 95% confidence interval -0.45 to -0.25, P<.001, I2=81%). Several sensitivity and subgroup analyses were performed suggesting that improvements in PTSD symptoms remained in favor of the active intervention group independent of the comparison condition, the type of cognitive behavioral therapy-based intervention, and the level of guidance provided. CONCLUSIONS: This review demonstrates an emerging evidence base supporting e-Mental Health to treat symptoms of PTSD.

Nation Building and Social Signaling in Southern Ontario: A.D. 1350-1650.

Pottery is a mainstay of archaeological analysis worldwide. Often, high proportions of the pottery recovered from a given site are decorated in some manner. In northern Iroquoia, late pre-contact pottery and early contact decoration commonly occur on collars-thick bands of clay that encircle a pot and extend several centimeters down from the lip. These decorations constitute signals that conveyed information about a pot's user(s). In southern Ontario the period A.D. 1350 to 1650 witnessed substantial changes in socio-political and settlement systems that included population movement, coalescence of formerly separate communities into large villages and towns, waxing and waning of regional strife, the formation of nations, and finally the development of three confederacies that each occupied distinct, constricted areas. Social network analysis demonstrates that signaling practices changed to reflect these regional patterns. Networks become more consolidated through time ultimately resulting in a "small world" network with small degrees of separation between sites reflecting the integration of communities within and between the three confederacies.

A rapid systematic review of what we know about alcohol use disorders and brief interventions in the criminal justice system.

PURPOSE: The purpose of this paper is to review the evidence of alcohol use disorders within the different stages of the criminal justice system in the UK. Furthermore it reviewed the worldwide evidence of alcohol brief interventions in the various stages of the criminal justice system. DESIGN/METHODOLOGY/APPROACH: A rapid systematic review of publications was conducted from the year 2000 to 2014 regarding the prevalence of alcohol use disorders in the various stages of the criminal justice system. The second part of the work was a rapid review of effectiveness studies of interventions for alcohol brief interventions. Studies were included if they had a comparison group. Worldwide evidence was included that consisted of up to three hours of face-to-face brief intervention either in one session or numerous sessions. FINDINGS: This review found that 64-88 per cent of adults in the police custody setting; 95 per cent in the magistrate court setting; 53-69 per cent in the probation setting and 5,913-863 per cent in the prison system and 64 per cent of young people in the criminal justice system in the UK scored positive for an alcohol use disorder. There is very little evidence of effectiveness of brief interventions in the various stages of the criminal justice system mainly due to the lack of follow-up data. SOCIAL IMPLICATIONS: Brief alcohol interventions have a large and robust evidence base for reducing alcohol use in risky drinkers, particularly in primary care settings. However, there is little evidence of effect upon drinking levels in criminal justice settings. Whilst the approach shows promise with some effects being shown on alcohol-related harm as well as with young people in the USA, more robust research is needed to ascertain effectiveness of alcohol brief interventions in this setting. ORIGINALITY/VALUE: This paper provides evidence of alcohol use disorders in the different stages of the criminal justice system in the UK using a validated tool as well as reviewing the worldwide evidence for short ( < three hours) alcohol brief intervention in this setting.

The Drinkers Degree: Risk Taking Behaviours amongst Undergraduate Student Drinkers.

UNLABELLED: Objective. To examine risk taking behaviours associated with alcohol consumption amongst UK undergraduate students. DESIGN AND METHODS: A cross-sectional web survey was used to assess attitudes and health behaviours. The survey included the Alcohol Use Disorders Identification Test (AUDIT). Students were also asked about why they drank alcohol; about their preferred alcoholic beverage; and if they had experienced any consequences associated with drinking alcohol as well as questions relating to sexual risk taking, drug use, and smoking. Results. 2779 (65% female; 84% White British) students completed some part of the survey. Of these, 98% (n = 2711) completed the AUDIT. Of the 92% that drank 66% (n = 1,643) were categorised as being AUDIT positive. 8% (n = 224) were categorised as probably alcohol dependent. Higher AUDIT scores were significantly associated with negative consequences such as unplanned sexual activity, physical injuries, and arguments. Other risk taking behaviours such as drug use and smoking were also found to be positively correlated with higher AUDIT scores; drug use; and smoking. Conclusions. The results from this study provide insight into students' alcohol consumption and associated risk taking. University policies need to protect students' overall health and wellbeing to ensure academic potential is maximised.

A pilot feasibility trial of alcohol screening and brief intervention in the police custody setting (ACCEPT): study protocol for a cluster randomised controlled trial.

BACKGROUND: There is evidence of an association between alcohol use and offending behaviour and around a quarter of police time is spent on alcohol-related incidents. Police custody, therefore, provides an important opportunity to intervene. This pilot trial aims to investigate whether a definitive evaluation of screening and brief interventions aimed at reducing risky drinking in arrestees is acceptable and feasible in the custody suite setting. METHODS: Screening will be carried out by trained detention officers or drug and alcohol workers in four police forces across two geographical areas (North East and South West England). Detention officers (or drug and alcohol workers) will be cluster randomised to one of three conditions: screening only (control group), screening followed immediately by 10 min of manualised brief structured advice delivered by the individual responsible for screening (intervention 1) or screening followed by 10 min of manualised brief structured advice delivered by the individual responsible for screening plus the offer of a subsequent 20-min session of behaviour change counselling delivered by a trained alcohol health worker (intervention 2). Participants will be arrestees aged 18+ who screen positive on the Alcohol Use Disorders Identification Test. Participants will be followed up at 6 and 12 months post-intervention. An embedded qualitative process evaluation will explore acceptability of alcohol screening and brief intervention to staff and arrestees as well as facilitators and barriers to the delivery of such approaches in this setting. RESULTS: Recruitment is currently underway and due to end May 2015. CONCLUSION: Results from this pilot trial will determine if a definitive evaluation is possible in the future and will provide stakeholder input to its design. TRIAL REGISTRATION: Reference number: ISRCTN89291046.

Benefits and costs of ecological restoration: Rapid assessment of changing ecosystem service values at a U.K. wetland.

Restoration of degraded land is recognized by the international community as an important way of enhancing both biodiversity and ecosystem services, but more information is needed about its costs and benefits. In Cambridgeshire, U.K., a long-term initiative to convert drained, intensively farmed arable land to a wetland habitat mosaic is driven by a desire both to prevent biodiversity loss from the nationally important Wicken Fen National Nature Reserve (Wicken Fen NNR) and to increase the provision of ecosystem services. We evaluated the changes in ecosystem service delivery resulting from this land conversion, using a new Toolkit for Ecosystem Service Site-based Assessment (TESSA) to estimate biophysical and monetary values of ecosystem services provided by the restored wetland mosaic compared with the former arable land. Overall results suggest that restoration is associated with a net gain to society as a whole of $199 ha(-1)y(-1), for a one-off investment in restoration of $2320 ha(-1). Restoration has led to an estimated loss of arable production of $2040 ha(-1)y(-1), but estimated gains of $671 ha(-1)y(-1) in nature-based recreation, $120 ha(-1)y(-1) from grazing, $48 ha(-1)y(-1) from flood protection, and a reduction in greenhouse gas (GHG) emissions worth an estimated $72 ha(-1)y(-1). Management costs have also declined by an estimated $1325 ha(-1)y(-1). Despite uncertainties associated with all measured values and the conservative assumptions used, we conclude that there was a substantial gain to society as a whole from this land-use conversion. The beneficiaries also changed from local arable farmers under arable production to graziers, countryside users from towns and villages, and the global community, under restoration. We emphasize that the values reported here are not necessarily transferable to other sites.

Occupational color vision standards: new prospects.

Occupational color vision standards in transport have been implemented for 100 years. A review of these standards has taken place early this century prompted by antidiscrimination laws in the workplace and several transport accidents. The Australian and Canadian Railways have developed new lanterns to address their occupational medical requirements. The Civil Aviation Authority in the UK has adopted the Color Assessment and Diagnosis (CAD) test as the standard for assessing color vision for professional flight crews. The methodology employed using the CAD test ensures that color deficient pilot applicants able to complete the most safety-critical task with the same accuracy as normal trichromats can be accepted for pilot training. This methodology can be extended for setting new color vision standards in other work environments.

Which extended paramedic skills are making an impact in emergency care and can be related to the UK paramedic system? A systematic review of the literature.

BACKGROUND: Increasing demand on the UK emergency services is creating interest in reviewing the structure and content of ambulance services. Only 10% of emergency calls have been seen to be life-threatening and, thus, paramedics, as many patients' first contact with the health service, have the potential to use their skills to reduce the demand on Emergency Departments. This systematic literature review aimed to identify evidence of paramedics trained with extra skills and the impact of this on patient care and interrelating services such as General Practices or Emergency Departments. METHODS: International literature from Medline, Embase, Cumulative Index of Nursing and Allied Health Literature (CINAHL), ProQuest, Scopus and grey literature from 1990 were included. Articles about any prehospital emergency care provider trained with extra skill(s) beyond their baseline competencies and evaluated in practice were included. Specific procedures for certain conditions and the extensively evaluated UK Emergency Care Practitioner role were excluded. RESULTS: 8724 articles were identified, of which 19 met the inclusion criteria. 14 articles considered paramedic patient assessment and management skills, two articles considered paramedic safeguarding skills, two health education and learning sharing and one health information. There is valuable evidence for paramedic assessing and managing patients autonomously to reduce Emergency Department conveyance which is acceptable to patients and carers. Evidence for other paramedic skills is less robust, reflecting a difficulty with rigorous research in prehospital emergency care. CONCLUSIONS: This review identifies many viable extra skills for paramedics but the evidence is not strong enough to guide policy. The findings should be used to guide future research, particularly into paramedic care for elderly people.

Worldwide prevalence of red-green color deficiency.

Literature that describes the prevalence of inherited red-green color deficiency in different populations is reviewed. Large random population surveys show that the prevalence of deficiency in European Caucasians is about 8% in men and about 0.4% in women and between 4% and 6.5% in men of Chinese and Japanese ethnicity. However, the male: female prevalence ratio is markedly different in Europeans and Asians. Recent surveys suggest that the prevalence is rising in men of African ethnicity and in geographic areas that have been settled by incoming migrants. It is proposed that founder events and genetic drift, rather than natural selection, are the cause of these differences.

Patients' awareness of postoperative adhesions: results from a multi-centre study and online survey.

PURPOSE: To analyse and to compare how female patients are informed about adhesions and their related problems by surgeons preoperatively. METHODS: Over 8 weeks 105 patients (Germany) and 82 (UK) patients admitted for laparoscopic or open abdominopelvic surgery were interviewed preoperatively in a multi-centre study in Germany and the UK. 212 responses to an online survey were also analysed. RESULTS: Less than 50% of patients are made aware of adhesions. Even fewer patients were told about complications caused by adhesions. Lack of knowledge is cited by 46% of patients as a reason for health professionals not informing them about adhesions. 41% considered adhesions as not sufficiently important. Patients who had previously heard of adhesions were most commonly informed by physicians. CONCLUSIONS: There is lack of information among patients and physicians about adhesions and their complications. Written information before surgery and computer-based applications may help raise patient's awareness.

Cost-effectiveness of dryland forest restoration evaluated by spatial analysis of ecosystem services.

Although ecological restoration is widely used to combat environmental degradation, very few studies have evaluated the cost-effectiveness of this approach. We examine the potential impact of forest restoration on the value of multiple ecosystem services across four dryland areas in Latin America, by estimating the net value of ecosystem service benefits under different reforestation scenarios. The values of selected ecosystem services were mapped under each scenario, supported by the use of a spatially explicit model of forest dynamics. We explored the economic potential of a change in land use from livestock grazing to restored native forest using different discount rates and performed a cost-benefit analysis of three restoration scenarios. Results show that passive restoration is cost-effective for all study areas on the basis of the services analyzed, whereas the benefits from active restoration are generally outweighed by the relatively high costs involved. These findings were found to be relatively insensitive to discount rate but were sensitive to the market value of carbon. Substantial variation in values was recorded between study areas, demonstrating that ecosystem service values are strongly context specific. However, spatial analysis enabled localized areas of net benefits to be identified, indicating the value of this approach for identifying the relative costs and benefits of restoration interventions across a landscape.

Identification of red-green colour deficiency: sensitivity of the Ishihara and American Optical Company (Hard, Rand and Rittler) pseudo-isochromatic plates to identify slight anomalous trichromatism.

Screening sensitivity, based on a specific number of errors, of the Ishihara plates and of the American Optical Company (Hardy, Rand and Rittler) plates (HRR plates) was determined by reviewing data obtained for 486 male anomalous trichromats identified and classified with the Nagel anomaloscope. Data were obtained for the 16 screening plates, with Transformation and Vanishing numeral designs, of the 38 plate Ishihara test, and for the four red-green screening plates (with six Vanishing designs) of the HRR test. Sensitivity of the Ishihara plates was found to be 97.7% on 4 errors and 98.4% on 3 errors. Only anomalous trichromats with slight deficiency, according to the anomaloscope matching range, made 8 errors or fewer. One screening error, a single missed figure, is normally allowed as a pass on the HRR test and 3 errors is often recommended as the fail criterion to eliminate false positive results. Twenty-three subjects made no error on the HRR screening plates and 12 subjects made a single error (35 anomalous trichromats). Screening sensitivity was therefore 92.8% using 2 errors as the fail criterion. Screening sensitivity was reduced to 87% when 3 errors was the fail criterion, and some deuteranomalous trichromats with moderate deficiency, according to the anomaloscope matching range, were not identified. Individuals who make a maximum of 2 errors on the HRR test, or on the Richmond HRR 4th Edition, should be re-examined with the Ishihara plates to determine their colour vision status. The present review confirms that the Ishihara test is a very sensitive screening test and identifies people with slight anomalous trichromatism. The HRR test is unsatisfactory for screening and should not be chosen solely for this purpose.

Occupational colour vision requirements for police officers.

Inclusion of public service professions in the UK Disability Discrimination Act in 2004 prompted a review of occupational colour vision requirements for police officers. Changes in the regulations which existed prior to 2003 were proposed. The aim of this study was to obtain the views of serving police officers in Northern Ireland on the importance of good colour discrimination in everyday police work and on the recruitment regulations for patrol constables introduced in 2003 in mainland UK. These views were obtained by means of a questionnaire and informal discussions. More than 65% of police officers who responded to the questionnaire considered that good colour vision was very important for effective policing. Fewer than 2% considered that colour vision was unimportant. Experienced police officers agreed that the employment of colour-deficient patrol constables, as permitted in the new regulations, would lead to reduced efficiency and organisational difficulties at the local level. A number of everyday activities were described which showed the need for accurate colour discrimination. The change in recruitment policy and the lack of clarity in the new regulations show inadequate appreciation of the needs of the occupation, of different types of colour vision anomalies and of the diagnostic function of colour vision tests. Failure to provide guidance on appropriate colour vision tests, examination procedures and counselling services is likely to result in inconsistent employment policies in different police forces. It is recommended that the colour vision standard in place prior to 2003 is reinstated at the recruitment stage. The Ishihara test should be used for screening, and colour-deficient applicants further examined with the Farnsworth D15 test as a replacement for the City University Test 2nd edition.

Failure of concordance of the Farnsworth D15 test and the Nagel anomaloscope matching range in anomalous trichromatism.

The Farnsworth D15 test (D15) was developed for use in occupational guidance. People with significant color deficiency, including all dichromats are expected to fail and people with slight color deficiency are expected to pass. Pass is a circular results diagram and fail an interlacing pattern with one or more red-green isochromatic errors (Farnsworth, 1947). The Nagel anomaloscope is a "gold standard" reference test for identifying and classifying red-green color deficiency. The matching range on the red/green mixture scale indicates the severity of the discrimination deficit. Pass/fail results for the D15 are presented for 107 protanomalous and 410 deuteranomalous trichromats and compared with the anomaloscope matching range. Thirty-six percent of the subjects examined failed the D15. Protanomalous trichromats are able to utilize perceived luminance contrast to obtain good results on the D15 but 42% of these subjects failed the D15 compared with 35% of deuteranomalous subjects. Failure of the D15 was clearly related to the Nagel matching range in deuteranomalous trichromatism but not in protanomalous trichromatism. For example, 84% of deuteranomalous subjects with matching ranges > 30 scale units failed the D15 but only 2% with matching ranges 15 scale units and 33% of subjects with matching ranges < 5 scale units were unsuccessful. Protanomalous trichromats with apparently minimal color deficiency are therefore shown to have poor practical hue discrimination ability as measured with this test.