Understanding primary care transformation and implications for ageing populations and health inequalities: a systematic scoping review of new models of primary health care in OECD countries and China.

BACKGROUND: Many countries have introduced reforms with the aim of primary care transformation (PCT). Common objectives include meeting service delivery challenges associated with ageing populations and health inequalities. To date, there has been little research comparing PCT internationally. Our aim was to examine PCT and new models of primary care by conducting a systematic scoping review of international literature in order to describe major policy changes including key 'components', impacts of new models of care, and barriers and facilitators to PCT implementation. METHODS: We undertook a systematic scoping review of international literature on PCT in OECD countries and China (published protocol: https://osf.io/2afym ). Ovid [MEDLINE/Embase/Global Health], CINAHL Plus, and Global Index Medicus were searched (01/01/10 to 28/08/21). Two reviewers independently screened the titles and abstracts with data extraction by a single reviewer. A narrative synthesis of findings followed. RESULTS: A total of 107 studies from 15 countries were included. The most frequently employed component of PCT was the expansion of multidisciplinary teams (MDT) (46% of studies). The most frequently measured outcome was GP views (27%), with < 20% measuring patient views or satisfaction. Only three studies evaluated the effects of PCT on ageing populations and 34 (32%) on health inequalities with ambiguous results. For the latter, PCT involving increased primary care access showed positive impacts whilst no benefits were reported for other components. Analysis of 41 studies citing barriers or facilitators to PCT implementation identified leadership, change, resources, and targets as key themes. CONCLUSIONS: Countries identified in this review have used a range of approaches to PCT with marked heterogeneity in methods of evaluation and mixed findings on impacts. Only a minority of studies described the impacts of PCT on ageing populations, health inequalities, or from the patient perspective. The facilitators and barriers identified may be useful in planning and evaluating future developments in PCT.

Parental responsiveness moderates the association between early-life stress and reduced telomere length.

Early-life stress, such as maltreatment, institutionalization, and exposure to violence, is associated with accelerated telomere shortening. Telomere shortening may thus represent a biomarker of early adversity. Previous studies have suggested that responsive parenting may protect children from the negative biological and behavioral consequences of early adversity. This study examined the role of parental responsiveness in buffering children from telomere shortening following experiences of early-life stress. We found that high-risk children had significantly shorter telomeres than low-risk children, controlling for household income, birth weight, gender, and minority status. Further, parental responsiveness moderated the association between risk and telomere length, with more responsive parenting associated with longer telomeres only among high-risk children. These findings suggest that responsive parenting may have protective benefits on telomere shortening for young children exposed to early-life stress. Therefore, this study has important implications for early parenting interventions.

The value of FDG positron emission tomography/computerised tomography (PET/CT) in pre-operative staging of colorectal cancer: a systematic review and economic evaluation.

OBJECTIVES: In the UK, colorectal cancer (CRC) is the third most common malignancy (behind lung and breast cancer) with 37,514 cases registered in 2006: around two-thirds (23,384) in the colon and one-third (14,130) in the rectum. Treatment of cancers of the colon can vary considerably, but surgical resection is the mainstay of treatment for curative intent. Following surgical resection, there is a comprehensive assessment of the tumour, it's invasion characteristics and spread (tumour staging). A number of imaging modalities are used in the pre-operative staging of CRCs including; computerised tomography (CT), magnetic resonance imaging, ultrasound imaging and positron emission tomography (PET). This report examines the role of CT in combination with PET scanning (PET/CT 'hybrid' scan). The research objectives are: to evaluate the diagnostic accuracy and therapeutic impact of fluorine-18-deoxyglucose (FDG) PET/CT for the pre-operative staging of primary, recurrent and metastatic cancer using systematic review methods; undertake probabilistic decision-analytic modelling (using Monte Carlo simulation); and conduct a value of information analysis to help inform whether or not there is potential worth in undertaking further research. DATA SOURCES: For each aspect of the research - the systematic review, the handsearch study and the economic evaluation - a database was assembled from a comprehensive search for published and unpublished studies, which included database searches, reference lists search and contact with experts. In the systematic review prospective and retrospective patient series (diagnostic cohort) and randomised controlled trials (RCTs) were eligible for inclusion. Both consecutive series and series that are not explicitly reported as consecutive were included. REVIEW METHODS: Two reviewers extracted all data and applied the criteria independently and resolved disagreements by discussion. Data to populate 2 × 2 contingency tables consisting of the number of true positives, true negatives, false positives and false negatives using the studies' own definitions were extracted, as were data relating to changes in management. Fourteen items from the Quality Assessment of Diagnostic Accuracy Studies checklist were used to assess the methodological quality of the included studies. Patient-level data were used to calculate sensitivity and specificity with confidence intervals (CIs). Data were plotted graphically in forest plots. For the economic evaluation, economic models were designed for each of the disease states: primary, recurrent and metastatic. These were developed and populated based on a variety of information sources (in particular from published data sources) and literature, and in consultation with clinical experts. RESULTS: The review found 30 studies that met the eligibility criteria. Only two small studies evaluated the use of FDG PET/CT in primary CRC, and there is insufficient evidence to support its routine use at this time. The use of FDG PET/CT for the detection of recurrent disease identified data from five retrospective studies from which a pooled sensitivity of 91% (95% CI 0.87% to 0.95%) and specificity of 91% (95% CI 0.85% to 0.95%) were observed. Pooled accuracy data from patients undergoing staging for suspected metastatic disease showed FDG PET/CT to have a pooled sensitivity of 91% (95% CI 87% to 94%) and a specificity of 76% (95% CI 58% to 88%), but the poor quality of the studies means the validity of the data may be compromised by several biases. The separate handsearch study did not yield any additional unique studies relevant to FDG PET/CT. Models for recurrent disease demonstrated an incremental cost-effectiveness ratio of £ 21,409 per quality-adjusted life-year (QALY) for rectal cancer, £ 6189 per QALY for colon cancer and £ 21,434 per QALY for metastatic disease. The value of handsearching to identify studies of less clearly defined or reported diagnostic tests is still to be investigated. CONCLUSIONS: The systematic review found insufficient evidence to support the routine use of FDG PET/CT in primary CRC and only a small amount of evidence supporting its use in the pre-operative staging of recurrent and metastatic CRC, and, although FDG PET/CT was shown to change patient management, the data are divergent and the quality of research is generally poor. The handsearch to identify studies of less clearly defined or reported diagnostic tests did not find additional studies. The primary limitations in the economic evaluations were due to uncertainty and lack of available evidence from the systematic reviews for key parameters in each of the five models. In order to address this, a conservative approach was adopted in choosing DTA estimates for the model parameters. Probabilistic analyses were undertaken for each of the models, incorporating wide levels of uncertainty particularly for the DTA estimates. None of the economic models reported cost-savings, but the approach adopted was conservative in order to determine more reliable results given the lack of current information. The economic evaluations conclude that FDG PET/CT as an add-on imaging device is cost-effective in the pre-operative staging of recurrent colon, recurrent rectal and metastatic disease but not in primary colon or rectal cancers. There would be value in undertaking an RCT with a concurrent economic evaluation to evaluate the therapeutic impact and cost-effectiveness of FDG PET/CT compared with conventional imaging (without PET) for the pre-operative staging of recurrent and metastatic CRC.

Water quality impacts of converting to a poultry litter fertilization strategy.

When improperly managed, land application of animal manures can harm the environment; however, limited watershed-scale runoff water quality data are available to research and address this issue. The water quality impacts of conversion to poultry litter fertilization on cultivated and pasture watersheds in the Texas Blackland Prairie were evaluated in this three-year study. Edge-of-field N and P concentrations and loads in surface runoff from new litter application sites were compared with losses under inorganic fertilization. The impact on downstream nutrient loss was also examined. In the fallow year with no fertilizer application, nutrient losses averaged 3 kg N ha(-1) and 0.9 kg P ha(-1) for the cultivated watersheds and were below 0.1 kg ha(-1) for the pasture watersheds. Following litter application, PO(4)-P concentrations in runoff were positively correlated to litter application rate and Mehlich-3 soil P levels. Following litter application, NO(3)-N and NH(4)-N concentrations in runoff were typically greater from cultivated watersheds, but PO(4)-P concentrations were greater for the pasture watersheds. Total N and P loads from the pasture watersheds (0.2 kg N ha(-1) and 0.7 kg P ha(-1)) were significantly lower than from the cultivated watersheds (32 kg N ha(-1) and 5 kg P ha(-1)) partly due to lower runoff volumes from the pasture watersheds. Downstream N and P concentrations and per-area loads were much lower than from edge-of-field watersheds. Results demonstrate that a properly managed annual litter application (4.5 Mg ha(-1) or less depending on litter N and P content) with supplemental N should supply necessary nutrients without detrimental water quality impacts.

Infiltration and adsorption of dissolved atrazine and atrazine metabolites in buffalograss filter strips.

Vegetated filter strips (VFS) potentially reduce the off-site movement of herbicides from adjacent agricultural fields by increasing herbicide mass infiltrated (Minf) and mass adsorbed (Mas) compared with bare field soil. However, there are conflicting reports in the literature concerning the contribution of Mas to the VFS herbicide trapping efficiency (TE). Moreover, no study has evaluated TE among atrazine (6-chloro-N-ethyl-N'-isopropyl-[1,3,5]triazine-2,4-diamine) and atrazine metabolites. This study was conducted to compare TE, Minf, and Mas among atrazine, diaminoatrazine (DA, 6-chloro[1,3,5]triazine-2,4-diamine), deisopropylatrazine (DIA, 6-chloro-N-ethyl-[1,3,5]triazine-2,4-diamine), desethylatrazine (DEA, 6-chloro-N-isopropyl-[1,3,5]triazine-2,4-diamine), and hydroxyatrazine (HA, 6-hydroxy-N-ethyl-N'-isopropyl-[1,3,5]triazine-2,4-diamine) in a buffalograss VFS. Runoff was applied as a point source upslope of a 1- x 3-m microwatershed plot at a rate of 750 L h(-1). The point source was fortified at 0.1 microg mL(-1) atrazine, DA, DIA, DEA, and HA. After crossing the length of the plot, water samples were collected at 5-min intervals. Water samples were extracted by solid phase extraction and analyzed by high performance liquid chromatography (HPLC) photodiode array detection. During the 60-min simulation, TE was significantly greater for atrazine (22.2%) compared with atrazine metabolites (19.0%). Approximately 67 and 33% of the TE was attributed to Minf and Mas, respectively. These results demonstrate that herbicide adsorption to the VFS grass, grass thatch, and/or soil surface is an important retention mechanism, especially under saturated conditions. Values for Mas were significantly higher for atrazine compared with atrazine's metabolites. The Mas data indicate that atrazine was preferentially retained by the VFS grass, grass thatch, and/or soil surface compared with atrazine's metabolites.

Comparision of atrazine and metolachlor affinity for bermudagrass ( Cynodon dactylon L.) and two soils.

Given that bermudagrass is being used as one of the grasses of choice in grass filter strip plantings as an acceptable grass to reduce off-target losses of herbicides, laboratory experiments were conducted to determine and compare the relative affinity of bermudagrass, a Weswood soil, and a Houston Black soil for atrazine (6-chloro- N-ethyl- N-isopropyl-1,3,5-triazine-2,4-diamine) and metolachlor (2-chloro- N-(2-ethyl-6-methylphenyl)- N-(2-methoxy-1-methyethyl) acetamide). Experiments were also conducted to determine if the presence of one herbicide affects the relative affinity of the other compound to these sorbents. The experiments were carried out using radiolabeled atrazine and metolachlor. Results were reported in disintegrations min(-1) (dpms) and converted to K(d) to determine and compare relative affinity. Both K(d) values for relative affinity of atrazine (86.2) and metolachlor (131.5) to bermudagrass were significantly greater than those of the two soils, Weswood (atrazine, 20.0 and metolachlor, 28.4) and Houston Black (atrazine, 35.8 and metolachlor, 33.5). The two compounds were also mixed together to mimic the common practice of applying atrazine and metolachlor simultaneously as a tank mix. Relative affinity of atrazine to any of the sorbents was not affected by the presence of metolachlor. Similarly, when comparing the affinity of metolachlor alone to that of metolachlor with atrazine present in the solution, no significant differences were observed for bermudagrass or the Weswood soil. However, on the Houston Black soil, the presence of atrazine significantly increased the soil's affinity for metolachlor.

Attachment for infants in foster care: the role of caregiver state of mind.

The concordance between foster mothers' attachment state of mind and foster infants' attachment quality was examined for 50 foster mother-infant dyads. Babies had been placed into the care of their foster mothers between birth and 20 months of age. Attachment quality was assessed between 12 and 24 months of age, at least 3 months after the infants' placement into foster care. The two-way correspondence between maternal state of mind and infant attachment quality was 72%, kappa = .43, similar to the level seen among biologically intact mother-infant dyads. Contrary to expectations, age at placement was not related to attachment quality. Rather, concordance between maternal state of mind and infant attachment was seen for relatively late-placed babies, as well as early placed babies. These findings have two major implications. First, following a disruption in care during the first year and a half of life, babies appear capable of organizing their behavior around the availability of new caregivers. Second, these data argue for a nongenetic mechanism for the intergenerational transmission of attachment.

The challenge of treatment for clients with dismissing states of mind.

Thirty-four clients with serious psychopathological disorders were videotaped solving interpersonal problems with significant others or with case managers. Differential reliance on dismissing states of mind was examined in relation to behavioral ratings of clients during the interactions, and in relation to changes in clients' and partners' reports of feelings. Clients who relied more on dismissing strategies showed greater rejection of significant others, but not of case managers, compared with clients who relied more on preoccupied strategies. The partners of dismissing clients reported greater sadness following problem-solving interactions than the partners of preoccupied clients. Clients who relied more on dismissing strategies spent less time on task when interacting with their case managers than clients who relied more on preoccupied strategies, and reported more confusion following these interactions. These findings suggest that treatment is likely to provide a particularly challenging context for adults with dismissing states of mind.

Systematic review in diagnostic radiology.

Systematic review (SR) already makes a major contribution to evidence-based healthcare by making the review process transparent and by reducing bias. SR has been successfully applied to observational studies. Radiologists have already begun to make an impact in dentistry by using SR as a decision-making tool. Central to SR is establishment of a research question, selection criteria, a search plan, a literature search, an appraisal of the identified literature by the selection criteria; an analysis and a formulation of recommendations. With regard to the literature search, electronic databases (Medline, Embase, Science Citation Index, Lilacs), controlled subject headings, exploding and free-text searching, handsearching and the gray literature are discussed.

The development of attachment in new relationships: single subject analyses for 10 foster infants.

This paper presents single-subject analyses of newly developing attachment relationships in 10 foster infant-caregiver dyads. Using a diary methodology, at least 2 months of daily data were provided by foster parents on infants' attachment behaviors. Foster infant attachment was also assessed using the Strange Situation. Foster mother state of mind regarding attachment was measured using the Adult Attachment Interview. For eight infants, diary data revealed predominant patterns of attachment behavior emerging within 2 months of placement. In most cases, diary data predicted Strange Situation classifications. Both Strange Situation and diary data indicated that the three children placed in foster care before 12 months of age with foster parents having primary or secondary autonomous states of mind were classified as having secure attachments. The five children placed after 12 months of age showed predominantly insecure attachment behavior in the diary and were classified as insecure in the Strange Situation. Contingency analyses of behavioral sequences reported in the diary revealed that foster parents tended to complement their foster childrens' attachment behaviors.

Inhibition of prostaglandin synthesis reduces cyclic AMP levels and inhibits chondrogenesis in cultured chick limb mesenchyme.

The present study investigated effects of inhibiting the synthesis of prostaglandins (PGs) on cyclic AMP concentrations and chondrogenesis in cultured chick limb mesenchyme. Indomethacin produced concentration-dependent inhibition of both PGE(2) synthesis and chondrogenesis over a concentration range of 50--200 microM. Half maximal inhibition of PGE(2) was achieved with 50 microM concentrations of the drug which also produced visibly reduced amounts of cartilage matrix in cell cultures as evaluated by Alcian green staining on day 6 of culture. The inhibitory effects of indomethacin on chondrogenesis were largely reversed by addition of 1 mM dibutyryl cAMP, indicating that cells could still respond to cyclic AMP stimulation. Endogenous levels of cyclic AMP, which increased by 6 fold during the six days of culture in control cells, did not increase significantly from dissociated cells at the time of plating (day 0) in indomethacin- treated cultures. The results indicate that inhibition of the prechondrogenic rise in PGE(2) concentrations in limb mesenchyme prevents the increase in cyclic AMP levels which occur during this same period resulting in inhibition of chondrogenesis. The data provide further support for the hypothesis that PGE(2), through its effects on the adenylate cyclase-cAMP system, plays an important role in the differentiation of cartilage.

Effective treatment relationships for persons with serious psychiatric disorders: the importance of attachment states of mind.

Participants were 54 clients with serious psychiatric disorders and 21 clinical case managers. Clients' serious psychiatric disorders included Axis I diagnoses, such as schizophrenia and bipolar disorder. This study examined how attachment states of mind of both clients and case managers influenced the effectiveness of therapeutic relationships and client functioning. Client and case manager attachment states of mind interacted in predicting the working alliance and client functioning. Specifically, clients who were more deactivating with respect to attachment had better alliances and functioned better with less deactivating case managers, whereas clients who were less deactivating worked better with more deactivating case managers. These findings highlight the importance of clinicians and clients being matched in ways that balance their interpersonal and emotional strategies.

Immunomodulatory screening test of corn oil administered orally to female mice: effect of timing of dosing within 24 hours.

The effect of varying the dose-delivery time within a 24 h period (12:12 light-dark cycle) on the immunomodulatory properties of corn oil administered by gavage to 120 B6C3F1 female mice was investigated. Mice, housed in six separate boxes equipped with timers to regulate light onset and offset (staggered by 4 h increments), were treated for 5 consecutive days by intragastric (i.g.), administration of 5 mL/kg corn oil. Negative and positive control mice were given sham injections (needle inserted, but no injection). Sheep red blood cells (SRBCs) were injected intraperitoneally (i.p.) on the fifth day. Three days later, positive control mice were given cyclophosphamide intraperitoneally (80 mg/kg). Four days after SRBC injection, mice were weighed and killed, and spleens and thymuses were removed and weighed. Spleens were brought to single-cell suspensions and tested for an antibody response to the SRBC. Plaque-forming cells (PFCs), as measured per spleen, per 10(6) viable spleen cells or per 10(6) total spleen cells, exhibited significant circadian rhythms for mice given corn oil, but not for sham-gavage- and cyclophosphamide-treated mice. The peak response (acrophase, phi) occurred at 21 h, 22 h, and 23 h after lights on (HALO), respectively, with PFC values significantly different between the different time points. Corn oil and sham gavage affected the circadian pattern of antibody production; there was a high-amplitude (21-27%) rhythm observed when mice were treated with corn oil and no rhythm when mice received the sham-gavage treatment. In addition to testing mice near the end of the daily dark span and/or early light span to obtain a maximum immune response, this finding points to the importance of including as controls a group of animals that are not treated at all and a group given vehicle alone, rather than only sham-treated animals, for comparison with experimentally treated animals.

The influence of vehicle gavage on seasonality of immune system parameters in the B6C3F1 mouse.

Seasonal hyporesponsiveness and other immune system variations were observed in female B6C3F1 mice during routine screening tests for immunomodulation. In a retrospective assessment, 4 years of data from over 1200 naive, vehicle, and immunosuppressed (cyclophosphamide-treated) control mice were compiled and analyzed for uniformity and significant circannual pattern of immune response. Endpoints included body, spleen, and thymus weights and an immunotoxicity assessment which enumerates specific antibody plaque-forming cells (PFC) in the spleen following immunization with sheep red blood cells. Dosing vehicles were water, corn oil, or 1% methyl cellulose instilled by oral gavage in a 5-20 ml/kg volume once daily for 5 days. Four days later, terminal organ and body weights were recorded and PFC were quantitated. Upon analysis, individual datapoints were arrayed in consistent circannual and seasonal patterns. In naive mice, the yearly peak response in circannual rhythm (acrophase) for body weight and PFC parameters occurred in the summer, with acrophases for spleen and thymus weights located in the spring. Vehicle gavage modulated the circannual/seasonal means and acrophases of all measured endpoints in distinct patterns which varied by vehicle. Body weight was the endpoint least affected by vehicle treatment. Corn oil was the vehicle resulting in the most dramatic effects on natural rhythm. As expected, the naive mice receiving an ip injection of cyclophosphamide exhibited significant decreases (p

13-week inhalation toxicity study of menthol cigarette smoke.

Menthol is a common pharmaceutical, food and tobacco flavouring ingredient used for its minty characteristics and cooling effects. A 13-wk comparative nose-only smoke inhalation toxicity study was conducted using an American-style, cellulose acetate-filtered, non-menthol reference cigarette and a similarly blended test cigarette containing 5000 ppm synthetic l-menthol tobacco. Male and female Fischer 344 rats were exposed for 1 hr/day, 5 days/wk for 13 wk at target mainstream smoke particulate concentrations of 200, 600 or 1200 mg/m3, while control rats were exposed to filtered air. Internal dose biomarkers (blood carboxyhaemoglobin, serum nicotine and serum continine) indicated equivalent exposures were obtained for the two cigarettes. Effects typically noted in rats exposed to high levels of mainstream tobacco smoke were similar for both cigarette types and included reduced body weights (males slightly more affected than females), increased heart-to-body weight ratios and lung weights, and histopathological changes in the respiratory tract. Rats exposed to reference cigarette smoke displayed a dose-related increase in nasal discharge that was not observed in menthol smoke-exposed rats. All smoke-related effects diminished significantly during a 6-wk non-exposure recovery period. The results of this 13-wk smoke inhalation study indicated that the addition of 5000 ppm menthol to tobacco had no substantial effect on the character or extent of the biological responses normally associated with inhalation of mainstream cigarette smoke in rats.

Clinicians as caregivers: role of attachment organization in treatment.

The relationship between case managers' attachment organization and interventions used with clients who have serious psychopathological disorders was examined. Adult Attachment Interviews were administered to 27 clients and their 18 case managers. Interviews were coded by means of Kobak's Q-set, which yields scores for secure-insecure and preoccupied-dismissing attachment strategies. Case managers were interviewed during each of 5 months regarding their most recent interventions; interventions were coded for depth of intervention and attention to dependency needs. Compared with secure case managers, insecure case managers attended more to dependency needs and intervened in greater depth with preoccupied clients than they did with dismissing clients. Case managers who were more preoccupied intervened with their clients in greater depth than did case managers who were more dismissing.

An immunotoxicity assessment of food flavouring ingredients.

A rapid screening protocol incorporating key elements of the US National Toxicology Program's immunotoxicity tier testing strategy was used to evaluate the effects of 35 commonly used food flavouring ingredients on humoral and cell-mediated immune responses. The test compounds were administered intragastrically on a daily basis for 5 days at three dose levels to female CD-1 or B6C3F1 mice, 6-8 wk old. A host resistance assay (Listeria monocytogenes bacterial challenge) was conducted to assess cell-mediated immunity. Humoral immunity was measured by the antibody plaque-forming cell (PFC) response to sheep erythrocytes. Body weights, lymphoid organ weights and spleen cellularity were also measured. Cyclophosphamide (80 mg/kg) served as an immunosuppressive positive control agent. The results indicated that the majority of the flavouring ingredients tested did not modulate the cell-mediated or humoral immune response. However, at very high dose levels, two of the materials tested, peppermint oil and citral dimethyl acetal, did increase mortality rate and reduce survival time in the host resistance assay. Neither of these materials significantly altered the PFC response. This rapid, economical screening battery for potential immunotoxicants proved to be a useful means of evaluating a large number of structurally diverse compounds and mixtures to prioritize them for more definitive testing.

Psychophysiology in attachment interviews: converging evidence for deactivating strategies.

By asking the subject to consider a host of potentially threatening attachment-related issues, the Adult Attachment Interview (AAI) allows an assessment of different strategies for regulating the attachment system. These strategies can be assessed along the 2 dimensions of security/anxiety and deactivation/hyperactivation. The greatest inferential leaps may be in characterizing strategies as deactivating. For example, individuals using deactivating strategies often report extremely positive relationships with parents, display restricted recall of attachment memories, and play down the significance of early attachment experiences. If these descriptive features are guided by a strategy that requires diverting attention from attachment information, subjects employing this strategy should experience conflict or inhibition during the Attachment Interview. In the present study, skin conductance levels were monitored for 50 college students during a baseline period and throughout the Attachment Interview. Subjects employing deactivating strategies showed marked increases in skin conductance levels from baseline to questions asking them to recall experiences of separation, rejection, and threat from parents. This finding supports the notion that individuals employing deactivating attachment strategies experience conflict or inhibition during the Attachment Interview.

Functional measurement assessment of young children's ability to predict future behavior.

The reported experiments demonstrate that young children's ability to use previous behavioral information to predict future behavior emerges on quantitative, but not dichotomous, judgment tasks. In a first experiment, kindergartners, second graders, and fourth graders made quantitative liking judgments and predictions for peers after being presented 2 pieces of behavioral information. Children of all 3 age groups used both pieces of information in their liking judgments and predictions. In a second experiment, kindergartners were presented with 2 types of tasks; one was a quantitative prediction, comparable to the task in Experiment 1, and the second were dichotomous predictions, comparable to judgment tasks typically used in other experiments. Children's predictions were significantly more consistent with the behavioral information on the quantitative task than on either of the dichotomous tasks. These results suggest that young children believe in the ability of interpersonal behavior, but have difficulty dealing with the complexity of some prediction tasks.