Adolescent Cannabis Misuse Scale: Longitudinal Associations with Substance Use, Mental Health, and Social Determinants of Health in Early Adulthood.

BACKGROUND: Some patterns of cannabis use may presage risk for long-term negative effects. We examined associations between a novel adolescent cannabis misuse scale and early-adult life course outcomes. METHODS: We performed a secondary data analysis of a cohort of Los Angeles, CA high school students from grade 9 through age 21. Participants reported baseline individual demographic and family characteristics at grade 9, adolescent cannabis misuse (8-items) and alcohol misuse (12-items) at grade 10, and outcomes at age 21. We used multivariable regression to model the associations of cannabis misuse scale score with problem substance use (defined as any of: 30-day illegal drug use, 30-day use of another's prescription to get high, hazardous drinking) and several secondary outcomes (behavioral, mental health, academic, social determinants of health), adjusting for covariates. Parallel analyses were conducted for alcohol misuse. RESULTS: The 1,148 participants (86% retention) were 47% male, 90% Latinx, 87% US born, and 40% native English speakers. Approximately 11.4% and 15.9% of participants reported at least one item on the cannabis and alcohol misuse scales, respectively. At age 21, approximately 6.7% of participants reported problem substance use, which was associated with both Cannabis and Alcohol Misuse Scales (OR 1.31, 95%CI[1.16, 1.49] and OR 1.33, 95%CI[1.18, 1.49], respectively). Both scales were similarly associated with outcomes in all four categories. CONCLUSIONS: The Adolescent Cannabis Misuse Scale is a promising tool for identifying early patterns of substance use that predict future negative outcomes and enabling early intervention at a critical period in youth development.

The longitudinal relationship of school climate with adolescent social and emotional health.

BACKGROUND: Schools and school climate are thought to influence academic outcomes as well as child and adolescent development, health and well-being. We sought to examine the relationship between several aspects of the school climate with adolescent social-emotional health outcomes. METHODS: We analysed data from the Reducing Inequities through Social and Educational change Follow-up (RISE UP) Study, a longitudinal natural experimental study of Los Angeles high school students collected from 2013 to 2018. We analysed data on the portion of the sample that completed the baseline, 10th grade and 11th grade surveys (n=1114). Students reported their perceptions of school climate at 10th grade and social-emotional outcomes including grit, self-efficacy, depression, hopelessness, and stress at baseline (9th grade) and at 11th grade. Multivariable regressions adjusted for student and parental demographics and baseline social-emotional states tested associations between school climate and each outcome. RESULTS: Students who reported being in authoritative school environments in 10th grade, one that is highly supportive and highly structured, had subsequently higher levels of self-efficacy (p< 0.001) and grit (p=0.01). They also had fewer depressive symptoms (p=0.008), and less hopelessness (p = 0.01), stress at school (p=0.002) and stress about the future (p=0.03) reported in 11th grade. CONCLUSIONS: School climate, and particularly an authoritative school environment, is strongly associated with better social-emotional health among adolescents. Relationship with teachers and their disciplinary style may be a focus for future interventions to improve the social-emotional health of children.

Adherence to the SEP-1 Sepsis Bundle in Hospital-Onset v. Community-Onset Sepsis: a Multicenter Retrospective Cohort Study.

BACKGROUND: Sepsis is the leading cause of in-hospital death. The SEP-1 sepsis bundle is a protocol for early sepsis care that requires providers to diagnose and treat sepsis quickly. Limited evidence suggests that adherence to the sepsis bundle is lower in cases of hospital-onset sepsis. OBJECTIVE: To compare sepsis bundle adherence in hospital-onset vs. community-onset sepsis. DESIGN: Retrospective cohort study using multivariable analysis of clinical data. PARTICIPANTS: A total of 4658 inpatients age 18 or older were identified by diagnosis codes consistent with sepsis or disseminated infection. SETTING: Four university hospitals in California between 2014 and 2016. MAIN OUTCOMES AND MEASURES: The primary outcome was adherence to key components of the sepsis bundle defined by the Centers for Medicare and Medicaid Services in their core measure, SEP-1. Covariates included clinical characteristics related to the patient, infection, and pathogen. KEY RESULTS: Compared with community-onset, cases of hospital-onset sepsis were less likely to receive SEP-1 adherent care (relative risk 0.33, 95% confidence interval 0.29-0.38, p < 0.001). With the exception of vasopressors (RR 1.11, p = 0.002), each component of SEP-1 evaluated-blood cultures (RR 0.76, p < 0.001), serum lactate (RR 0.51, p < 0001), broad-spectrum antibiotics (RR 0.62, p < 0.001), intravenous fluids (0.47, p < 0.001), and follow-up lactate (RR 0.71, p < 0.001)-was less likely to be performed within the recommended time frame in hospital-onset sepsis. Within the hospital, cases of hospital-onset sepsis arising on the ward were less likely to receive SEP-1-adherent care than were cases arising in the intensive care unit (RR 0.68, p = 0.004). CONCLUSIONS: Inpatients with hospital-onset sepsis receive different management than individuals with community-onset sepsis. It remains to be determined whether system-level factors, provider-level factors, or factors related to measurement explain the observed variation in care or whether variation in care affects outcomes.

Engaging Parents to Prevent Adolescent Substance Use: A Randomized Controlled Trial.

Objectives. To test whether providing information to parents about their child's academic performance and behavior in school will lead to lower rates of adolescent substance use.Methods. We performed a randomized controlled trial in Los Angeles, California. We enrolled 318 seventh graders and their parents in 2014 and collected data through 2016. Half of the participants had parents with income less than $15 000, and 81% were Latino. During this intervention, Linking Information and Families Together, we sent parents weekly text messages, telephone calls, or e-mails about missed assignments, grades, and behavior. Parents reported their monitoring and parenting self-efficacy; students reported their use and intentions to use alcohol, marijuana, and other drugs.Results. By the end of eighth grade, lifetime use of alcohol or marijuana was 18.2% in the control group and 10.2% in the intervention group (P = .02). Parenting self-efficacy, parent-child relationship, and student's grades were similar between groups.Conclusions. The intervention successfully reduced adolescent alcohol and marijuana initiation between grades 7 and 8. The intervention cost $15 per student per year but could be automated, reducing the marginal cost toward zero. The intervention holds promise as a scalable and innovative approach to reducing substance use.Trial Registration. ClinicalTrials.gov Identifier: NCT02129153.

Racial/Ethnic and Socioeconomic Differences in Colorectal and Breast Cancer Treatment Quality: The Role of Physician-level Variations in Care.

BACKGROUND: Despite a large body of research showing racial/ethnic and socioeconomic disparities in cancer treatment quality, the relative role of physician-level variations in care is unclear. OBJECTIVE: To examine the effect of physicians on disparities in breast and colorectal cancer care. SUBJECTS: Linked SEER Medicare data were used to identify Medicare beneficiaries diagnosed with colorectal and breast cancer during 1995-2007 and their treating physicians. RESEARCH DESIGN: We identified treating physicians from Medicare claims data. We measured the use of NIH guideline-recommended therapies from SEER and Medicare claims data, and used logistic models to examine the relationship between race/ethnicity, socioeconomic status, and cancer quality of care. We used physician fixed effects to account for between-physician variations in treatment. RESULTS: Minority and low socioeconomic status beneficiaries with breast and colorectal cancer were less likely to receive any recommended treatments as compared with whites. Overall, between-physician variation explained <20% of the total variation in quality of care. After accounting for between-physician differences, median household income explained 14.3%, 18.4%, and 13.2% of the variation in use of breast-conserving surgery, chemotherapy, and radiation for breast cancer, and 13.7%, 12.9%, and 12.6% of the within-physician variation in use of colorectal surgery, chemotherapy, and radiation for colorectal cancer, whereas race and ethnicity explained <2% of the within-physician variation in cancer care. CONCLUSIONS: Between-physician variations partially explain racial disparities in cancer care. Residual within-physician disparities may be due to differences in patient-provider communication, patient preferences and treatment adherence, or unmeasured clinical severity.

Chaos, Hubbub, and Order Scale and Health Risk Behaviors in Adolescents in Los Angeles.

OBJECTIVE: To determine the relationship between household chaos and substance use, sexual activity, and violence-related risk behaviors in adolescents. STUDY DESIGN: We analyzed cross-sectional data among 929 high-school students in Los Angeles who completed a 90-minute interview that assessed health behaviors and household chaos with the 14-question Chaos, Hubbub, and Order Scale (CHAOS). Using the generalized estimating equation and adjusting for personal, parental, and family covariates, we examined associations of CHAOS score with substance use, sexual activity, and violent behavior outcome variables. We also examined the role of depression and school engagement as mediators. RESULTS: Mean (SD) age of the 929 students was 16.4 (1.3) years, 516 (55%) were female, and 780 (84%) were Latino. After adjustment, compared with students with CHAOS score 0, those students with the greatest scores (5-14) had ORs of 3.1 (95% CI 1.1-8.7) for smoking, 2.6 (95% CI 1.6-4.4) for drinking, 6.1 (95% CI 1.8-21) for substance use at school, and 1.9 (95% CI 1.1-3.3) for fighting in the past 12 months. Associations between CHAOS score and sexual risk and other violent behaviors were not significant. Depression and school engagement attenuated the associations. CONCLUSIONS: In this group of adolescents, greatest CHAOS score was associated with increased odds of risky health behaviors, with depression and school engagement as potential mediators. In the future, CHAOS score could be measured to assess risk for such behaviors or be a target for intervention to reduce chances of engaging in these behaviors.

Assessing the connection between health and education: identifying potential leverage points for public health to improve school attendance.

OBJECTIVES: We examined multiple variables influencing school truancy to identify potential leverage points to improve school attendance. METHODS: A cross-sectional observational design was used to analyze inner-city data collected in Los Angeles County, California, during 2010 to 2011. We constructed an ordinal logistic regression model with cluster robust standard errors to examine the association between truancy and various covariates. RESULTS: The sample was predominantly Hispanic (84.3%). Multivariable analysis revealed greater truancy among students (1) with mild (adjusted odds ratio [AOR] = 1.57; 95% confidence interval [CI] = 1.22, 2.01) and severe (AOR = 1.80; 95% CI = 1.04, 3.13) depression (referent: no depression), (2) whose parents were neglectful (AOR = 2.21; 95% CI = 1.21, 4.03) or indulgent (AOR = 1.71; 95% CI = 1.04, 2.82; referent: authoritative parents), (3) who perceived less support from classes, teachers, and other students regarding college preparation (AOR = 0.87; 95% CI = 0.81, 0.95), (4) who had low grade point averages (AOR = 2.34; 95% CI = 1.49, 4.38), and (5) who reported using alcohol (AOR = 3.47; 95% CI = 2.34, 5.14) or marijuana (AOR = 1.59; 95% CI = 1.06, 2.38) during the past month. CONCLUSIONS: Study findings suggest depression, substance use, and parental engagement as potential leverage points for public health to intervene to improve school attendance.

Health and Care Needs of Young Adults Exiting Jail.

Reentry is a difficult juncture for young adults (ages 18-24 years), who simultaneously face challenges of emerging adulthood. Although their health-related needs may be substantial, little is reported on young adults' reentry health care and social service needs. Furthermore, empirical measurements of factors affecting their engagement in reentry services after jail are lacking. We sought to describe health needs and predictors of linkages to reentry services for the 2,525 young adult participants in the Whole Person Care-LA Reentry program (WPC Reentry). Descriptive statistics were calculated and chi-square tests, t tests, and logistic regression were performed to identify factors associated with linkage to WPC Reentry postrelease compared with only engaging with WPC Reentry prerelease. Most participants (72.6%) were male, 80.2% were Hispanic or Black, and 60.9% had been unhoused. Mental health (57.2%) and substance use disorders (45.8%) were common, physical health was overall good (mean Charlson Comorbidity Index score 0.53), and social needs, especially housing, were high (40.7%). Older age (i.e., closer to 25 years) and history of being unhoused were associated with higher postrelease engagement in WPC Reentry (age: odds ratio [OR] = 1.06, p = .01; history of being unhoused: OR = 1.18, p = .05). Attentiveness to younger clients and to addressing housing needs may be key for successful reentry care linkages.

"CYP3A4 Poor and Intermediate Metabolizers Have a Higher Rate of Steroid-Induced Intraocular Pressure Response".

PURPOSE: Evaluate the relationship between CYP3A4 phenotype, the gene encoding the enzyme that metabolizes exogenous steroid, and the rate of steroid-induced intraocular pressure (IOP) response. MATERIALS AND METHODS: Lymphocyte-derived DNA sequencing of CYP3A4 from 10073 patients was completed using the PGRN-Seq assay. Subjects with CYP3A4 intermediate metabolizer or slower phenotypes were identified and compared with controls matched by age, race and sex. All subjects had at least three eye exams with at least an exam while on topical/systemic/local steroid in any body location except the eye. Patients with pre-existing glaucoma or glaucoma suspect were excluded. RESULTS: Of the 10073 patients, there were 63 patients who had CYP3A4 poor or intermediate metabolizer phenotype. Of the 63 patients, 22 had documented steroid use. Fifty-nine percent (13/22) of patients with CYP3A4 poor/intermediate metabolizer had a steroid-induced IOP response of 3 mmHg or more, significantly higher compared to 23% (5/22) of matched controls (P=0.031). Although more poor /intermediate metabolizers were steroid responders, the average IOP elevation in steroid responders in both groups were similar (5.0 ± 2.5 mmHg in CYP3A4 poor/intermediate metabolizers compared to 4.1 ± 2.1mmHg in controls, P=0.327). Family history of glaucoma was similar in both groups (7/22 vs. 8/22, P=1.0). CONCLUSION: Reduced CYP3A4 phenotypes may help identify patients at a higher risk of steroid-induced IOP elevation. PRCIS: This retrospective study examined patients with sequenced CYP3A4, a gene encoding an enzyme that metabolizes exogenous steroids. When compared to normal metabolizers, CYP3A4 poor or intermediate metabolizers have a higher steroid-induced IOP response rate.

The association of religiosity with overweight/obese body mass index among Asian Indian immigrants in California.

OBJECTIVE: The aim of this study was to examine the association between religiosity and overweight or obese body mass index among a multi-religious group of Asian Indian immigrants residing in California. METHODS: We examined cross-sectional survey data obtained from in-language telephone interviews with 3228 mostly immigrant Asian Indians in the 2004 California Asian Indian Tobacco Survey using multivariate logistic regression. RESULTS: High self-identified religiosity was significantly associated with higher BMI after adjusting for socio-demographic and acculturation measures. Highly religious Asian Indians had 1.53 greater odds (95% CI: 1.18, 2.00) of being overweight or obese than low religiosity immigrants, though this varied by religious affiliation. Religiosity was associated with greater odds of being overweight/obese for Hindus (OR 1.54; 95% CI: 1.08, 2.22) and Sikhs (OR 1.88; 95% CI: 1.07, 3.30), but not for Muslims (OR 0.69; 95% CI: 0.28, 1.70). CONCLUSIONS: Religiosity in Hindus and Sikhs, but not immigrant Muslims, appears to be independently associated with greater body mass index among Asian Indians. If this finding is confirmed, future research should identify potentially mutable mechanisms by which religion-specific religiosity affects overweight/obesity risk.

Factors inhibiting institutional responses to domestic violence in Kyrgyzstan.

The study identifies factors that limit effective institutional responses to domestic violence (DV) in Kyrgyzstan, in the context of recent legislative actions aimed at reducing DV through improvements in law enforcement, judicial processes, and provision of social services. The study uses qualitative, grounded theory methods to analyze interviews and focus groups with 83 professionals working in these sectors. Two major themes emerge from the analysis: (1) barriers to effective institutional responses from internal challenges and constraints, and (2) social resources and challenges identified as important to provide a better collective response. The study highlights the need for capacity development within institutions and broader social learning to overcome existing barriers and better align outcomes with the intentions of recent legislation. Standardized training, awareness-raising, enhanced roles for educators and religious leaders, better coordinated social service provision, rehabilitation for victims and perpetrators, and family-centered school-based interventions are identified as targets for improving responsiveness.

Perceptions of School Climate Shape Adolescent Health Behavior: A Longitudinal Multischool Study.

BACKGROUND: Adolescent behaviors and academic outcomes are thought to be shaped by school climate. We sought to identify longitudinal associations between school climate measures and downstream health and academic outcomes. METHODS: Data from a longitudinal survey of public high school students in Los Angeles were analyzed. Eleventh-grade health and academic outcomes (dependent variables, eg, substance use, delinquency, risky sex, bullying, standardized exams, college matriculation), were modeled as a function of 10th-grade school climate measures (independent variables: institutional environment, student-teacher relationships, disciplinary style), controlling for baseline outcome measures and student/parental covariates. RESULTS: The 1114 student respondents (87.8% retention), were 46% male, 90% Latinx, 87% born in the United States, and 40% native English speakers. Greater school order and teacher respect for students were associated with lower odds of multiple high risk behaviors including 30-day alcohol use (odds ratio [OR] 0.81; 95% confidence interval [CI] [0.72, 0.92] and OR 0.73; [0.62, 0.85]) and 30-day cannabis use (OR 0.74; [0.59, 0.91] and OR 0.76; [0.63, 0.92]). Neglectful disciplinary style was associated with multiple poor health and academic outcomes while permissive disciplinary style was associated with favorable academic outcomes. IMPLICATIONS FOR SCHOOL HEALTH POLICY, PRACTICE, AND EQUITY: School health practitioners may prospectively leverage school environment, teacher-student relationships, and disciplinary style to promote health and learning. CONCLUSIONS: Our findings identify specific modifiable aspects of the school environment with critical implications for life course health.

Outcome of the AVID College Preparatory Program on Adolescent Health: A Randomized Trial.

BACKGROUND AND OBJECTIVES: Academic tracking is a widespread practice, separating students by prior academic performance. Clustering lower performing students together may unintentionally reinforce risky peer social networks, school disengagement, and risky behaviors. If so, mixing lower performing with high performing youth ("untracking") may be protective, leading to better adolescent health. METHODS: Advancement via Individual Determination (AVID), a nationally-disseminated college preparatory program, supports placing middle-performing students in rigorous college-preparatory classes alongside high-performing peers. We conducted the first randomized, controlled trial of AVID in the United States, randomizing 270 students within 5 large public high schools to receive AVID (AVID group) versus usual school programming (control group). Participants completed surveys at the transition to high school (end of eighth grade/ beginning of ninth grade) and the end of ninth grade. Intent-to-treat analyses tested whether AVID resulted in healthier social networks (primary outcome), health behaviors, and psychosocial wellbeing. RESULTS: At follow-up, AVID students had lower odds of using any substance (odds ratio [OR] 0.66, 95% confidence interval [CI] 0.48-0.89) and associating with a substance-using peer (OR 0.74, 95% CI 0.45-0.98), and higher odds of associating with a peer engaged in school (OR 1.73, 95% CI 1.11-2.70). Male AVID students had lower stress and higher self-efficacy, grit, and school engagement than control students (P < .05 for all). No adverse health effects among high-performing peers were observed. CONCLUSIONS: AVID positively impacts social networks, health behaviors, and psychosocial outcomes suggesting academic untracking may have substantial beneficial spillover effects on adolescent health.

Correction: Gender stigma awareness is associated with adolescent risky health behaviors.

[This corrects the article DOI: 10.1371/journal.pone.0251332.].

A symphony within: Frequent participation in performing arts predicts higher positive mental health in young adults.

RATIONALE: Positive mental health is a critical component of overall mental health, but our understanding of the potential drivers of positive mental health is lacking. Participation in the arts may contribute to positive mental health through the mechanism of flow, a mental state of becoming completely engrossed in an enjoyable activity. Participation in performing arts specifically may be especially predictive of positive mental health due to its collective nature. OBJECTIVE AND METHODS: This study uses the Population Study of Income Dynamics (PSID) Transition to Adulthood Sample (N = 5657 person-years) to investigate whether participation in performing arts predicts positive mental health in young adults in the US through adjusted least squares and individual-level fixed-effects linear regression models across three waves of data per individual. Additionally, the study investigates different levels of participation to establish a dose response and employs stratified analyses by race/ethnicity, income, and gender. RESULTS: Results show that, compared to no participation, participating in the performing arts every day is associated with an increase in positive mental health of a 0.315 effect size [p < 0.001]. White and higher income individuals are more likely to participate in the arts than people of color and lower income individuals. Yet, the association between performing arts and positive mental health is similar, if not greater, for people of color than it is for white individuals. CONCLUSION: This study shows strong associations between frequent performing arts participation and positive mental health and suggests that more resources should be allocated to performing arts access for young adults from diverse backgrounds.

Turning Vicious Cycles Into Virtuous Ones: the Potential for Schools to Improve the Life Course.

Adolescence is a critical transition period that sets the stage for adulthood and future health outcomes. Marked by key developmental milestones in brain maturation, increasing independence from parents, and greater connections to peers, adolescence is also a time of heightened risk for behavioral health problems, including substance use, violence, delinquency, and mental health issues. High school completion is a significant life course event and a powerful social determinant of health and health disparities. Jessor's Theory of Problem Behavior suggests that adolescent health behaviors and mental health problems are closely tied to poor educational outcomes and peer network formation in a reinforcing feedback loop, or vicious cycle, often leading to school failure, school disengagement, and drop-out. Schools are a novel platform through which vicious cycles can be disrupted and replaced with virtuous ones, simultaneously improving education and health. This article describes the potential for schools to transform health trajectories through interventions creating positive and supportive school climates. In addition, new models such as the Whole School Whole Community Whole Child Model promote whole child well-being, including cognitive, social, emotional, psychological, and physical development. Full-service community schools can serve as a hub coordinating and integrating all available resources to better respond to the needs of children and families. Present in every neighborhood, schools are a way to reach every school-age child and improve their health trajectories, providing an important platform for life course intervention research.

Association of Attending a High-Performing High School With Substance Use Disorder Rate and Health Outcomes in Young Adults.

Importance: Interventions directly targeting social factors, such as education, may have the potential to greatly improve health. Objective: To examine the association of attending a high-performing public charter high school with rates of substance use disorder and physical and mental health. Design, Setting, and Participants: This cohort study used the random school admissions lottery system of high-performing public charter high schools in low-income neighborhoods of Los Angeles, California, to examine the health outcomes of students who applied to at least 1 of 5 of these high schools. Participants attended 147 different high schools and were randomly selected from those who won the admissions lottery (intervention group) and those who were placed on a waiting list (control group). Participants were surveyed at the end of grade 8 through transition into grade 9 and then from grade 10 through 3 years after high school completion (at age 21 years). Surveys were conducted from March 2013 through November 2021. Intervention: Attendance at a high-performing public charter high school. Main Outcomes and Measures: Self-reported alcohol use disorder and cannabis misuse, delinquent behaviors, physical and mental health, and body mass index. Results: Of the 1270 participants at baseline (mean [SD] age, 14.2 [0.47] years; 668 female individuals [52.6%]). The control group included 576 individuals (45.4%), and 694 individuals (54.6%) were in the intervention group. Both groups were similar in almost all characteristics at baseline, and the median (IQR) follow-up was 6.4 (6.0-6.7) years. Participants attending a high-performing public charter high school had a 53.33% lower rate of hazardous or dependent alcohol use disorder compared with those in the control group (5.43% vs 11.64%; difference, -6.21% [95% CI, -11.87% to -0.55%]; P = .03). Among male participants, the intervention group had a 42.05% lower rate of self-reported fair or poor physical health (13.33% vs 23.01%; difference, -9.67% [95% CI, -18.30% to -1.05%]; P = .03) and a 32.94% lower rate of obesity or overweight (29.28% vs 43.67%; difference, -14.38% [95% CI, -25.74% to -3.02%]; P = .02) compared with the control group. Among female participants, attending a high-performing public charter high school was associated with worse physical health outcomes (30.29% vs 13.47% reporting fair or poor health; difference, 16.82% [95% CI, 0.36% to 33.28%]; P = .045) and higher rates of overweight or obesity (52.20% vs 32.91%; difference, 19.30% [95% CI, 3.37% to 35.22%]; P = .02) at age 21 years. Few differences in mental health outcomes were observed. Adjusting for educational outcomes did not significantly change these findings. Conclusions and Relevance: Results of this study suggest that attending a high-performing public charter high school was associated with lower rates of substance use disorder independent of academic achievement. Physical health and obesity outcomes were also better but only for young men; the intervention group had worse physical health outcomes among young women for unclear reasons. Schools are a potent social determinant of health and an important target for future health interventions.

Development and validation of a prediction model for the risk of developing febrile neutropenia in the first cycle of chemotherapy among elderly patients with breast, lung, colorectal, and prostate cancer.

PURPOSE: Current guidelines recommend prophylactic use of granulocyte-colony stimulating factors (G-CSF) when febrile neutropenia (FN) risk is greater than 20%. Advanced age is a risk factor for FN; however, little is known about the impact of other factors on the incidence of FN in an older population. PATIENTS AND METHODS: We analyzed SEER-Medicare data (1994-2005) to develop and validate a prediction model for hospitalization with fever, infection, or neutropenia occurring after chemotherapy initiation for patients with breast, colorectal, prostate, and lung cancer. RESULTS: In multivariate analysis (N = 58,053) independent predictors of FN included advanced stage at diagnosis [stage 2 (OR 1.29; 95% CI: 1.09-1.53), stage 3 (1.38; 95% CI: 1.19-1.60), and stage 4 (1.57; 95% CI: 1.35-1.83)], number of associated comorbid conditions [one condition (1.13; 95% CI: 1.02-1.28), two conditions (1.39; 95% CI: 1.22-1.57), and three or more conditions (1.81; 95% CI: 1.61-2.04)], receipt of myelosuppressive chemotherapy (1.11; 95% CI: 0.94-1.32), and receipt of chemotherapy within 1 month of diagnosis [1 to 3 months (0.70; 95% CI: 0.62-0.80) and greater than 3 months (0.63; 95% CI: 0.55-0.73)]. CONCLUSION: We created a prediction model for febrile neutropenia with first cycle of chemotherapy in a large population of elderly patients with common malignancies.