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Nudge-based misinformation interventions are presented as cheap and effective ways to reduce the spread of misinformation online. However, despite online information environments typically containing relatively low volumes of misinformation, most studies testing the effectiveness of nudge interventions present equal proportions of true and false information. As the effectiveness of nudges can be highly context-dependent, it is imperative to validate the effectiveness of nudge-based interventions in environments with more realistic proportions of misinformation. The current study (N = 1387) assessed the effectiveness of a combined accuracy and social-norm nudge in simulated social-media environments with varying proportions of misinformation (50%, 20%, and 12.5%) relative to true and non-news-based (i.e., "social") information. The nudge intervention was effective at improving sharing discernment in conditions with lower proportions of misinformation, providing ecologically valid support for the use of nudge-based interventions to counter misinformation propagation on social media., (© 2024. The Author(s).)

Misinformation on social media is a pervasive challenge. In this study (N = 415) a social-media simulation was used to test two potential interventions for countering misinformation: a credibility badge and a social norm. The credibility badge was implemented by associating accounts, including participants', with a credibility score. Participants' credibility score was dynamically updated depending on their engagement with true and false posts. To implement the social-norm intervention, participants were provided with both a descriptive norm (i.e., most people do not share misinformation) and an injunctive norm (i.e., sharing misinformation is the wrong thing to do). Both interventions were effective. The social-norm intervention led to reduced belief in false claims and improved discrimination between true and false claims. It also had some positive impact on social-media engagement, although some effects were not robust to alternative analysis specifications. The presence of credibility badges led to greater belief in true claims, lower belief in false claims, and improved discrimination. The credibility-badge intervention also had robust positive impacts on social-media engagement, leading to increased flagging and decreased liking and sharing of false posts. Cumulatively, the results suggest that both interventions have potential to combat misinformation and improve the social-media information landscape., (© 2024. The Author(s).)

Given the potential negative impact reliance on misinformation can have, substantial effort has gone into understanding the factors that influence misinformation belief and propagation. However, despite the rise of social media often being cited as a fundamental driver of misinformation exposure and false beliefs, how people process misinformation on social media platforms has been under-investigated. This is partially due to a lack of adaptable and ecologically valid social media testing paradigms, resulting in an over-reliance on survey software and questionnaire-based measures. To provide researchers with a flexible tool to investigate the processing and sharing of misinformation on social media, this paper presents The Misinformation Game-an easily adaptable, open-source online testing platform that simulates key characteristics of social media. Researchers can customize posts (e.g., headlines, images), source information (e.g., handles, avatars, credibility), and engagement information (e.g., a post's number of likes and dislikes). The platform allows a range of response options for participants (like, share, dislike, flag) and supports comments. The simulator can also present posts on individual pages or in a scrollable feed, and can provide customized dynamic feedback to participants via changes to their follower count and credibility score, based on how they interact with each post. Notably, no specific programming skills are required to create studies using the simulator. Here, we outline the key features of the simulator and provide a non-technical guide for use by researchers. We also present results from two validation studies. All the source code and instructions are freely available online at https://misinfogame.com ., (© 2023. The Author(s).)

Given that being misinformed can have negative ramifications, finding optimal corrective techniques has become a key focus of research. In recent years, several divergent correction formats have been proposed as superior based on distinct theoretical frameworks. However, these correction formats have not been compared in controlled settings, so the suggested superiority of each format remains speculative. Across four experiments, the current paper investigated how altering the format of corrections influences people's subsequent reliance on misinformation. We examined whether myth-first, fact-first, fact-only, or myth-only correction formats were most effective, using a range of different materials and participant pools. Experiments 1 and 2 focused on climate change misconceptions; participants were Qualtrics online panel members and students taking part in a massive open online course, respectively. Experiments 3 and 4 used misconceptions from a diverse set of topics, with Amazon Mechanical Turk crowdworkers and university student participants. We found that the impact of a correction on beliefs and inferential reasoning was largely independent of the specific format used. The clearest evidence for any potential relative superiority emerged in Experiment 4, which found that the myth-first format was more effective at myth correction than the fact-first format after a delayed retention interval. However, in general it appeared that as long as the key ingredients of a correction were presented, format did not make a considerable difference. This suggests that simply providing corrective information, regardless of format, is far more important than how the correction is presented., (© 2021. The Author(s).)

Misinformation often has an ongoing effect on people's memory and inferential reasoning even after clear corrections are provided; this is known as the continued influence effect. In pursuit of more effective corrections, one factor that has not yet been investigated systematically is the narrative versus non-narrative format of the correction. Some scholars have suggested that a narrative format facilitates comprehension and retention of complex information and may serve to overcome resistance to worldview-dissonant corrections. It is, therefore, a possibility that misinformation corrections are more effective if they are presented in a narrative format versus a non-narrative format. The present study tests this possibility. We designed corrections that are either narrative or non-narrative, while minimizing differences in informativeness. We compared narrative and non-narrative corrections in three preregistered experiments (total N = 2279). Experiment 1 targeted misinformation contained in fictional event reports; Experiment 2 used false claims commonly encountered in the real world; Experiment 3 used real-world false claims that are controversial, in order to test the notion that a narrative format may facilitate corrective updating primarily when it serves to reduce resistance to correction. In all experiments, we also manipulated test delay (immediate vs. 2 days), as any potential benefit of the narrative format may only arise in the short term (if the story format aids primarily with initial comprehension and updating of the relevant mental model) or after a delay (if the story format aids primarily with later correction retrieval). In all three experiments, it was found that narrative corrections are no more effective than non-narrative corrections. Therefore, while stories and anecdotes can be powerful, there is no fundamental benefit of using a narrative format when debunking misinformation.

The COVID-19 pandemic has understandably dominated public discourse, crowding out other important issues such as climate change. Currently, if climate change enters the arena of public debate, it primarily does so in direct relation to the pandemic. In two experiments, we investigated (1) whether portraying the response to the COVID-19 threat as a "trial run" for future climate action would increase climate-change concern and mitigation support, and (2) whether portraying climate change as a concern that needs to take a "back seat" while focus lies on economic recovery would decrease climate-change concern and mitigation support. We found no support for the effectiveness of a trial-run frame in either experiment. In Experiment 1, we found that a back-seat frame reduced participants' support for mitigative action. In Experiment 2, the back-seat framing reduced both climate-change concern and mitigation support; a combined inoculation and refutation was able to offset the drop in climate concern but not the reduction in mitigation support., Competing Interests: Ullrich Ecker receives funding from the Australian Research Council (ARC); Stephan Lewandowsky consults for, and collaborates with, the Joint Research Center of the European Commission. He receives funding from the ARC, the ESRC (via CREST), and the Volkswagen Foundation. All other authors declare no competing interests., (© 2020 Elsevier Ltd. All rights reserved.)

The multiple choice procedure (MCP) is used to assess the relative reinforcing value of concurrently available stimuli. The MCP was originally developed to assess the reinforcing value of drugs; the current within-subjects study employed the MCP to assess the reinforcing value of gambling behavior. Participants (N = 323) completed six versions of the MCP that presented hypothetical choices between money to be used while gambling ($10 or $25) versus escalating amounts of guaranteed money available immediately or after delays of either 1 week or 1 month. Results suggest that choices on the MCP are correlated with other measures of gambling behavior, thus providing concurrent validity data for using the MCP to quantify the relative reinforcing value of gambling. The MCP for gambling also displayed sensitivity to reinforcer magnitude and delay effects, which provides evidence of criterion validity. The results are consistent with a behavioral economic model of addiction and suggest that the MCP could be a valid tool for future research on gambling behavior.

Previous research suggests that personalized feedback interventions (PFI) can be an effective tool in reducing risky alcohol use among college students; however, little is known about how students perceive the individual components that are typically used during PFIs. In the current study, participants (N = 219, 63.5% female, 84% Caucasian, undergraduates enrolled in introductory psychology courses) reported their drinking behavior in the past month, and then immediately received a computerized PFI based on their self-reported alcohol use. The PFI was modeled from the Brief Alcohol Screening and Intervention for College Students (BASICS) approach and included 10 separate feedback components presented in random order. Participants provided acceptability ratings on each of the 10 components. Overall, participants found the PFI generally acceptable, with females rating the PFI as more acceptable than males, and binge drinkers (defined as 5 or more drinks on an occasion for males and 4 or more drinks for females) rating the PFI more acceptable than nonbinge drinkers. Differences in acceptability emerged across the 10 components, as participants rated the practical cost components (e.g., money spent on alcohol, calories consumed) as more acceptable than didactic information (e.g., impact of blood alcohol levels) and personal negative consequences. The results are similar to a previous study that examines student reactions to PFIs (Miller & Leffingwell, 2013). Overall, the findings suggest that college students prefer certain feedback components to others. Moreover, the findings indicate that future research is needed to examine the relationship between preferred components and treatment outcomes to determine which components are most effective for reducing risky drinking.

Anecdotal reports suggest that the currently approved dosing interval of agalsidase alfa (0.2 mg/kg/2 weeks) for Fabry disease treatment is too long. This randomised, double-blind, placebo-controlled, crossover study investigated three altered dosing intervals. 18 Fabry patients received three agalsidase alfa dosing schedules, each for four weeks (A: 0.2 mg/kg∗2 weeks, B: 0.1 mg/kg/week, C: 0.2 mg/kg/week). Health state, pain levels, sweat volume and latency and plasma and urinary globotriaosylceramide levels were recorded throughout the study. No significant differences were found among the schedules for the primary efficacy outcome of self-assessed health state, or for pain scores. A trend toward increased sweat volume on QSART testing, and reduced urine globotriaosylceramide concentration were seen with treatment schedule C. Agalsidase alfa was safe and well tolerated with all schedules. In conclusion, the primary analyses did not find weekly infusions of agalsidase alfa to be statistically better than the approved dosing schedule however the data indicates that further studies with more patients over a longer period are required to more accurately determine the optimum dose and schedule., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Background and Aims: Using two parental clones of outcrossing Trifolium ambiguum as a potential model system, we examined how during seed development the maternal parent, number of seeds per pod, seed position within the pod, and pod position within the inflorescence influenced individual seed fresh weight, dry weight, water content, germinability, desiccation tolerance, hardseededness, and subsequent longevity of individual seeds., Methods: Near simultaneous, manual reciprocal crosses were carried out between clonal lines for two experiments. Infructescences were harvested at intervals during seed development. Each individual seed was weighed and then used to determine dry weight or one of the physiological behaviour traits., Key Results: Whilst population mass maturity was reached at 33-36 days after pollination (DAP), seed-to-seed variation in maximum seed dry weight, when it was achieved, and when maturation drying commenced, was considerable. Individual seeds acquired germinability between 14 and 44 DAP, desiccation tolerance between 30 and 40 DAP, and the capability to become hardseeded between 30 and 47 DAP. The time for viability to fall to 50 % (p(50)) at 60 % relative humidity and 45 degrees C increased between 36 and 56 DAP, when the seed coats of most individuals had become dark orange, but declined thereafter. Individual seed f. wt at harvest did not correlate with air-dry storage survival period. Analysing survival data for cohorts of seeds reduced the standard deviation of the normal distribution of seed deaths in time, but no sub-population showed complete uniformity of survival period., Conclusions: Variation in individual seed behaviours within a developing population is inherent and inevitable. In this outbreeder, there is significant variation in seed longevity which appears dependent on embryo genotype with little effect of maternal genotype or architectural factors.

Background and Aims: Most priming studies have been conducted on commercial seed lots of unspecified uniformity and maturity, and subsequent seed longevity has been reported to both increase and decrease. Here a seed lot of Digitalis purpurea L. with relatively uniform maturity and known history was used to analyse the effects of priming on seed longevity in air-dry storage., Methods: Seeds collected close to natural dispersal and dried at 15% relative humidity (RH), 15 degrees C, were placed into experimental storage (60% RH, 45 degrees C) for 14 or 28 d, primed for 48 h at 0, -1, -2, -5, -10 or -15 MPa, re-equilibrated (47% RH, 20 degrees C) and then returned to storage. Further seed samples were primed for 2 or 48 h at -1 MPa and either dried at 15% RH, 15 degrees C or immediately re-equilibrated for experimental storage. Finally, some seeds were given up to three cycles of experimental storage and priming (48 h at -1 MPa)., Key Results: Priming at -1 MPa had a variable effect on subsequent survival during experimental storage. The shortest lived seeds in the control population showed slightly increased life spans; the longer lived seeds showed reduced life spans. In contrast, seeds first stored for 14 or 28 d before priming had substantially increased life spans. The increase tended to be greatest in the shortest lived fraction of the seed population. Both the period of rehydration and the subsequent drying conditions had significant effects on longevity. Interrupting air-dry storage with additional cycles of priming also increased longevity., Conclusions: The extent of prior deterioration and the post-priming desiccation environment affect the benefits of priming to the subsequent survival of mature seeds. Rehydration-dehydration treatments may have potential as an adjunct or alternative to the regeneration of seed accessions maintained in gene banks for plant biodiversity conservation or plant breeding.

Background and Aims: Seed quality may be compromised if seeds are harvested before natural dispersal (shedding). It has been shown previously that slow or delayed drying can increase potential quality compared with immediate rapid drying. This study set out to investigate whether or not there is a critical moisture content, below which drying terminates maturation events for seeds harvested after mass maturity but before dispersal., Methods: Seeds of foxglove (Digitalis purpurea) in the post-abscission pre-dispersal phase were held at between 15 and 95 % RH for 4 or 8 d, with or without re-hydration to 95 % RH for a further 4 d, before drying to equilibrium at 15 % RH. In addition, dry seeds were primed for 48 h at -1 MPa. Subsequent seed longevity was assessed at 60 % RH and 45 degrees C., Key Results: Rate of germination and longevity were improved by holding seeds at a wide range of humidities after harvest. Longevity was further improved by re-hydration at 95 % RH. Priming improved the longevity of the seeds dried immediately after harvest, but not of those first held at 95 % RH for 8 d prior to drying., Conclusions: Maturation continued ex planta in these post-abscission, pre-dispersal seeds of D. purpurea dried at 15-80 % RH at a rate correlated positively with RH (cf. ageing of mature seeds). Subsequent re-hydration at 95 % RH enabled a further improvement in quality. Priming seeds initially stored air-dry for 3 months also allowed maturation events to resume. However, once individual seeds within the population had reached maximum longevity, priming had a negative impact on their subsequent survival.

Research has demonstrated that brief interventions featuring personalized feedback can be used to decrease alcohol use among heavy-drinking college students. The current study investigated the efficacy of face-to-face and computer delivered interventions relative to an assessment-only control condition. The content of the personalized feedback was identical across the face-to-face and computerized conditions. There were 84 at-risk students assessed before, and 4 weeks after, the delivery of the interventions. The results suggest that both face-to-face and computerized interventions were equally successful in reducing the quantity and frequency of alcohol consumption, and that both interventions were more effective than the control condition. Participants also rated both interventions as acceptable, although the face-to-face intervention was given a more favorable rating. These initial results suggest that computerized interventions can be used to efficiently reduce alcohol use among college students. (PsycINFO Database Record (c) 2009 APA, all rights reserved).

The novel sialomucin, CD164, functions as both an adhesion receptor on human CD34+ cell subsets in bone marrow and as a potent negative regulator of CD34+ hemopoietic progenitor cell proliferation. These diverse effects are mediated by at least two functional epitopes defined by the mAbs, 103B2/9E10 and 105A5. We report here the precise epitope mapping of these mAbs together with that of two other CD164 mAbs, N6B6 and 67D2. Using newly defined CD164 splice variants and a set of soluble recombinant chimeric proteins encoded by exons 1-6 of the CD164 gene, we demonstrate that the 105A5 and 103B2/9E10 functional epitopes map to distinct glycosylated regions within the first mucin domain of CD164. The N6B6 and 67D2 mAbs, in contrast, recognize closely associated and complex epitopes that rely on the conformational integrity of the CD164 molecule and encompass the cysteine-rich regions encoded by exons 2 and 3. On the basis of their sensitivities to reducing agents and to sialidase, O-sialoglycoprotease, and N-glycanase treatments, we have characterized CD164 epitopes and grouped them into three classes by analogy with CD34 epitope classification. The class I 105A5 epitope is sialidase, O-glycosidase, and O-sialoglycoprotease sensitive; the class II 103B2/9E10 epitope is N-glycanase, O-glycosidase, and O-sialoglycoprotease sensitive; and the class III N6B6 and 67D2 epitopes are not removed by such enzyme treatments. Collectively, this study indicates that the previously observed differential expression of CD164 epitopes in adult tissues is linked with cell type specific post-translational modifications and suggests a role for epitope-associated carbohydrate structures in CD164 function.

Three distinct classes of epitopes on human CD164 have been identified. Two of these, recognized by the monoclonal antibodies 105A5 and 103B2/9E10, are the CD164 class I and class II functionally defined epitopes, which cooperate to regulate adhesion and proliferation of CD34(+) cell subsets. In this article, we demonstrate that these 2 CD164 epitopes are expressed on CD34(+) cells throughout ontogeny, in particular on CD34(+ )cell clusters associated with the ventral floor of the dorsal aorta in the developing embryo and on CD34(+) hematopoietic precursor cells in fetal liver, cord blood, and adult bone marrow. While higher levels of expression of these CD164 epitopes occur on the more primitive AC133(hi)CD34(hi)CD38(lo/-) cell population, they also occur on most cord blood Lin(-)CD34(lo/-)CD38(lo/- )cells, which are potential precursors for the AC133(hi)CD34(hi)CD38(lo/-) subset. In direct contrast to these common patterns of expression on hematopoietic precursor cells, notable differences in expression of the CD164 epitopes were observed in postnatal lymphoid and nonhematopoietic tissues, with the class I and class II CD164 epitopes generally exhibiting differential and often reciprocal cellular distribution patterns. This is particularly striking in the colon, where infiltrating lymphoid cells are CD164 class I-positive but class II-negative, while epithelia are weakly CD164 class II-positive. Similarly, in certain lymphoid tissues, high endothelial venules and basal and subcapsular epithelia are CD164 class II-positive, while lymphoid cells are CD164 class I-positive. It therefore seems highly likely that these CD164 class I and II epitopes will mediate reciprocal homing functions in these tissue types.

CD164 is a novel 80- to 90-kD mucin-like molecule expressed by human CD34(+) hematopoietic progenitor cells. Our previous results suggest that this receptor may play a key role in hematopoiesis by facilitating the adhesion of CD34(+) cells to bone marrow stroma and by negatively regulating CD34(+) hematopoietic progenitor cell growth. These functional effects are mediated by at least two spatially distinct epitopes, defined by the monoclonal antibodies (MoAbs), 103B2/9E10 and 105A5. In this report, we show that these MoAbs, together with two other CD164 MoAbs, N6B6 and 67D2, show distinct patterns of reactivity when analyzed on hematopoietic cells from normal human bone marrow, umbilical cord blood, and peripheral blood. Flow cytometric analyses revealed that, on average, 63% to 82% of human bone marrow and 55% to 93% of cord blood CD34(+) cells are CD164(+), with expression of the 105A5 epitope being more variable than that of the other identified epitopes. Extensive multiparameter flow cytometric analyses were performed on cells expressing the 103B2/9E10 functional epitope. These analyses showed that the majority (>90%) of CD34(+) human bone marrow and cord blood cells that were CD38(lo/-) or that coexpressed AC133, CD90(Thy-1), CD117(c-kit), or CD135(FLT-3) were CD164(103B2/9E10)+. This CD164 epitope was generally detected on a significant proportion of CD34(+)CD71(lo/-) or CD34(+)CD33(lo/-) cells. In accord with our previous in vitro progenitor assay data, these phenotypes suggest that the CD164(103B2/9E10) epitope is expressed by a very primitive hematopoietic progenitor cell subset. It is of particular interest to note that the CD34(+)CD164(103B2/9E10)lo/- cells in bone marrow are mainly CD19(+) B-cell precursors, with the CD164(103B2/9E10) epitope subsequently appearing on CD34(lo/-)CD19(+) and CD34(lo/-)CD20(+) B cells in bone marrow, but being virtually absent from B cells in the peripheral blood. Further analyses of the CD34(lo/-)CD164(103B2/9E10)+ subsets indicated that one of the most prominent populations consists of maturing erythroid cells. The expression of the CD164(103B2/9E10) epitope precedes the appearance of the glycophorin C, glycophorin A, and band III erythroid lineage markers but is lost on terminal differentiation of the erythroid cells. Expression of this CD164(103B2/9E10) epitope is also found on developing myelomonocytic cells in bone marrow, being downregulated on mature neutrophils but maintained on monocytes in the peripheral blood. We have extended these studies further by identifying Pl artificial chromosome (PAC) clones containing the CD164 gene and have used these to localize the CD164 gene specifically to human chromosome 6q21., (Copyright 1998 by The American Society of Hematology.)

The (2;5)(p23;q35) lymphoma-associated chromosomal translocation creates a novel fusion gene that incorporates parts of the anaplastic lymphoma kinase (ALK) receptor tyrosine kinase and nucleophosmin genes. We report here that the product of this fusion gene accumulates within the nucleoli of neoplastic cells, and that previous reports of a predominantly cytoplasmic localization for the protein represent a tissue-processing artifact. However, nucleolar accumulation of nucleophosmin-ALK may not be necessary for its oncogenic action, because an ALK protein expressed in a lymphoma carrying a variant (1;2) chromosomal translocation did not accumulate in nucleoli. Furthermore, an engineered hybrid TPR-ALK protein can transform rodent fibroblasts and produce lymphomas in mice while remaining confined to the cytoplasm. We propose that the transforming action of ALK may not be reliant on its nucleolar localization, a hypothesis that may have implications for studies of other proteins involved in oncogenesis that are relocalized after the creation of fusion genes.

Chromosomal rearrangement of the HRX (MLL, ALL-1, Htrx) gene situated at chromosome band 11q23 is one of the most frequent genetic changes in infant leukemias of myeloid and lymphoid lineage and in treatment-induced secondary leukemias. The HRX gene codes for a predicted 431-kD protein that shows significant homology to the Drosophila trithorax protein, an Hox epigenetic regulator. Typically, the region encoding the HRX gene is rearranged, mostly in reciprocal translocations with a number of partners, resulting in a range of fusion genes. However, this is not the only abnormality affecting HRX because partial duplication of the gene, as well as interstitial deletions, can occur. Despite extensive studies of HRX at the genetic level, the protein products of the HRX gene and their patterns of expression in normal and leukemic cells remain uncharacterized. In this study we analyzed the distribution and localization of HRX proteins in cell lines and human tissues, using both polyclonal and monoclonal antibodies. The specificity of these reagents was confirmed using cells transfected with the HRX-ENL fusion gene. Western blot analyses of protein extracts from cells carrying the t(11;19) and t(4;11) translocations showed HRX chimeric proteins whose migrations corresponded to the sizes predicted from analyses of translocation-induced fusion mRNAs expressed by the derivative 11 chromosomes. Immunocytochemical analysis showed a punctate distribution of wild-type and chimeric HRX proteins within cell nuclei, suggesting that HRX localizes to nuclear structures in cells with and without 11q23 translocations. Nuclear staining was found in the majority of tissues studied with the strongest reactivity in cerebral cortex, kidney, thyroid, and lymphoid tissues. Thus, HRX is widely expressed in most cell types including hematopoietic cells, a finding that precludes an immunocytochemical approach for diagnosis of leukemias bearing 11q23 structural abnormalities.

The t(2;5)(p23;q35) translocation, associated with anaplastic large-cell lymphoma (ALCL), results in the production of the nucleolar protein nucleophosmin-anaplastic lymphoma kinase (NPM-ALK) protein. This report describes an immunocytochemical study of the distribution of ALK and NPM-ALK proteins using a new monoclonal antibody, ALK1, that recognizes a formalin resistant epitope in both the 80-kD NPM-ALK chimeric and the 200-kD normal human ALK proteins. Cytoplasmic and nuclear labeling was seen in the t(2;5)+ SU-DHL-1 and Karpas 299 cell lines. Normal ALK protein expression was restricted to the central nervous system (in scattered neurons, glial cells, and endothelial cells). Two hundred and thirty-nine cases of lymphoma and 80 nonhematopoietic tumors were immunostained. Antibody ALK1 labeled 53.4% (39 of 73 cases) of CD30+ ALCL. A case of ALCL with a t(1;2) translocation was ALK1+. Three cases of CD30- ALCL with prominent nucleoli showed a unique pattern of coarse granular cytoplasmic labeling. All other tumors, including Hodgkin's disease and lymphomatoid papulosis, were ALK1-. These results indicate that reliable immunostaining of routine biopsy material for NPM-ALK and ALK proteins is feasible. Such analysis is of diagnostic importance, especially because t(2;5)+ ALCL cases have a good prognosis with appropriate treatment.

Little research has been directed toward an examination of the health needs of low-income Americans in relation to major governmental medical care programs designed originally to narrow the health gap between "poor" and "nonpoor." Analysis of unpublished data from the 1977 Health Interview Survey of the National Center for Health Statistics shows that about 75 per cent of the gap in restricted activity days and bed disability days--two common measures of the impact of ill-health--between "poor" and "nonpoor" populations is attributable to greater prevalence and severity of activity-limiting chronic conditions among low-income people. Although both income groups report similar types of chronic conditions resulting in activity limitation, the prevalence of all major chronic conditions is greater in the low-income population. Approximately 25 per cent of the low-income population bears the burden of these conditions; the majority of the "poor" report disability day levels similar to the "nonpoor." The substantial impact of chronic conditions should be an important consideration in meeting the health needs of the low-income population. Current government programs, such as Medicare and medicaid, however, are designed primarily to pay for acute care received in hospitals and in physicians' offices.

Enrollment trends for a large employee group were analyzed to determine the extent to which consumers chose Blue Cross or Health Maintenance Organization (HMO) health insurance under various premium differentials. Data were collected from employment records of six University of California campuses for the period 1967 to 1978. Enrollment in the Kaiser Foundation Health Plan (an HMO) more than doubled during this period while enrollment in Blue Cross remained relatively stable. This increased preference for Kaiser coverage was associated with a concurrent relative rise in costs to employees of Blue Cross coverage. These data suggest that consumers are sensitive to insurance costs, and that given the opportunity HMOs can compete effectively with traditional health insurance.

The authors present new results from the 1978 National Health Interview Survey concerning the use of physician services by the least healthy segment of the low-income population: those who are limited in their activities due to chronic conditions. Poor and nonpoor persons with chronic activity limitations report similar levels of physician visits. However, lower-income persons report more severe chronic conditions and hence appear to use less physician care relative to their needs. In addition, low-income persons with chronic activity limitations report more visits in hospital outpatient clinics and emergency rooms and fewer in doctor's offices compared with others with such limitations, and they are more likely to report hospital outpatient departments as their usual source of care. Unfortunately, hospital-based ambulatory care is often more episodic and fragmented than care provided in other settings. The authors concluded that care for this population could be improved greatly by restructuring responsibility for the care of the chronically ill within hospital outpatient departments.