Revisiting sample size planning for receiver operating characteristic studies: a confidence interval approach with precision and assurance

Objectives: Estimation of areas under receiver operating characteristic curves (AUCs) and their differences is a key task in diagnostic studies. We aimed to derive, evaluate, and implement simple sample size formulas for such studies with a focus on estimation rather than hypothesis testing. Materials and Methods: Sample size formulas were developed by explicitly incorporating pre-specified precision and assurance, with precision denoted by the lower limit of confidence interval and assurance denoted by the probability of achieving that lower limit. A new variance function was proposed for valid estimation allowing for unequal variances of observations in the disease and non-disease groups. Performance of the proposed formulas was evaluated through simulation. Results: Closed-form sample size formulas were obtained. Simulation results demonstrated that the proposed formulas produced empirical assurance probability close to the pre-specified assurance probability and empirical coverage probability close to the nominal 95%. Real-world worked examples were presented for illustration. Conclusions: Sample size formulas based on estimation of AUCs and their differences were developed. Simulation results suggested good performance in terms of achieving pre-specified precision and assurance probability. An online calculator for implementing the proposed formulas is openly available at https://dishu.page/calculator/.Comment: 28 pages, 3 table

Global assessment of the severity of epilepsy (GASE) Scale in children: Validity, reliability, responsiveness

Summary Objective The Global Assessment of Severity of Epilepsy (GASE) Scale is a single-item, 7-point global rating scale designed for neurologist-report of overall severity of epilepsy in children. Building on previous preliminary evidence of its validity and reliability for research and clinical use, this study evaluated the GASE Scale\u27s construct validity, reliability, and responsiveness to changes in severity of epilepsy. Methods Data used for the study arose from the Health-Related Quality of Life in Children with Epilepsy Study (HERQULES), a 2-year multicenter prospective cohort study (n = 374) with observations taken at baseline, and 6, 12, and 24 months after diagnosis. Construct validity and reliability were quantified using Spearman\u27s correlation and intraclass correlation coefficient (ICC). Responsiveness was assessed using both distribution-based and anchor-based indices. Results The GASE Scale was at least moderately correlated (r ≥ 0.30) with several key clinical aspects and most strongly correlated with frequency and intensity of seizures and interference of epilepsy or drugs with daily activities (r \u3e 0.30). Total variation in GASE Scale scores explained by seven core clinical aspects of epilepsy increased over time (R2 = 28% at baseline to R2 = 70% at 24 months). The GASE Scale had modest test-retest reliability (ICC range: 0.52-0.64) and was responsive to changes in clinical criteria (standardized response mean range: 0.49-0.68; probability of change range: 0.69-0.75; Guyatt\u27s responsiveness statistic range: 0.56-0.84). The GASE Scale showed potential to discriminate stable and changed patients according to select criteria and to a composite score (area under the receiver operating characteristic [ROC] curve range: 0.50-0.67). Significance Results offer additional evidence in support of the GASE Scale\u27s validity, reliability, as well as responsiveness to changes in severity of epilepsy in children. We conclude that the GASE Scale is a potentially useful tool for assessing the severity of epilepsy in both clinical and research settings

Breast Cancer Care in California and Ontario: Primary Care Protections Greatest Among the Most Socioeconomically Vulnerable Women Living in the Most Underserved Places

Background: Better health care among Canada’s socioeconomically vulnerable versus America’s has not been fully explained. We examined the effects of poverty, health insurance and the supply of primary care physicians on breast cancer care. Methods: We analyzed breast cancer data in Ontario (n = 950) and California (n = 6300) between 1996 and 2000 and followed until 2014. We obtained socioeconomic data from censuses, oversampling the poor. We obtained data on the supply of physicians, primary care and specialists. The optimal care criterion was being diagnosed early with node negative disease and received breast conserving surgery followed by adjuvant radiation therapy. Results: Women in Ontario received more optimal care in communities well supplied by primary care physicians. They were particularly advantaged in the most disadvantaged places: high poverty neighborhoods (rate ratio = 1.65) and communities lacking specialist physicians (rate ratio = 1.33). Canadian advantages were explained by better health insurance coverage and greater primary care access. Conclusions: Policy makers ought to ensure that the newly insured are adequately insured. The Medicaid program should be expanded, as intended, across all 50 states. Strengthening America’s system of primary care will probably be the best way to ensure that the Affordable Care Act’s full benefits are realized

The prevalence and impact of adolescent hospitalization to adult psychiatric units.

BACKGROUND: With increasing psychiatric hospitalizations among adolescents and constrained hospital resources, there are times when youth are hospitalized in adult inpatient psychiatry units. Evidence on the prevalence of this practice and associated impacts is lacking. AIMS: We sought to explore the prevalence, determinants, and outcomes related to the hospitalization of adolescents aged 12-17 years on adult inpatient psychiatry units in Ontario. METHODS: Using health administrative data, we constructed a cohort of adolescents with an inpatient psychiatric admission in Ontario (2007-2011). We classified adolescents as having an admission to an adult psychiatry unit or to other inpatient units. Multivariable regression models were used to estimate prevalence ratios (PR) for factors associated with adult admission, as well as risk ratios (RR) for the impact of adult admission on length of stay, discharge against medical advice, and 30-day readmission. RESULTS: Over the study period, 22.6% of adolescents with a psychiatric hospitalization (n = 16 998) had an admission to an adult psychiatry unit. Older age (16 vs. 15 years: PR = 2.27, 95% CI = 2.07-2.48; 17 vs. 15 years: PR = 2.91, 95% CI = 2.66-3.18), rural residence (PR = 1.46, 95% CI = 1.38-1.55), psychotic (PR = 1.25, 95% CI = 1.15-1.36) or personality disorder (PR = 1.59, 95% CI = 1.41-1.80) diagnoses, and involuntary status (PR = 2.18, 95% CI = 2.05-2.31) were independently associated with adult admission. Adolescents admitted to adult units were more likely to be discharged against medical advice (RR = 1.77, 95% CI = 1.45-2.17). CONCLUSIONS: Nearly one in four adolescent psychiatric admissions occurs on an adult psychiatric unit. These findings help to fill gaps in the prior literature, and highlight the need for further research to inform policy decisions and resource allocation for adolescent inpatient psychiatric care

Gender differences on the interacting effects of marital status and health insurance on long-term colon cancer survival in California, 1995-2014

Objectives. Long-term colon cancer survival is not well explained by main effects. We explored the interaction of age, gender, marital status, health insurance and poverty on 10-year colon cancer survival. Methods. California registry data were analyzed for 5,776 people diagnosed from 1995 to 2000; followed until 2014. Census data classified neighborhood poverty. We tested interactions with regressions and described them with standardized rates and rate ratios (RR). Results. The 5-way interaction was significant, suggesting larger 4-way disadvantages among non-Medicare-eligible people. A significant 4-way interaction was a 3-way interaction in non-high poverty neighborhoods only. Private insurance was protective for unmarried men (RR = 1.60) but not women, while it was protective for married women (RR = 1.22) but not men. This pattern seemed explained by lower-incomes of certain groups of unmarried women and married men and more prevalent underinsuring of unmarried men. Conclusions. Structural inequities related to the institutions of marriage and health care seem to affect women and men quite differently. Policy makers ought to be cognizant of such structural imbalances as future reforms of American health care are considered

Disparities among Minority Women with Breast Cancer Living in Impoverished Areas of California

Background: Interaction effects of poverty and health care insurance coverage on overall survival rates of breast cancer among women of color and non-Hispanic white women were explored. Methods: We analyzed California registry data for 2,024 women of color (black, Hispanic, Asian, Pacific Islander, American Indian, or other ethnicity) and 4,276 non-Hispanic white women (Anglo-European ancestries and no Hispanic-Latin ethnic backgrounds) diagnosed with breast cancer between the years 1996 and 2000 who were then followed until 2011. The 2000 US census categorized rates of neighborhood poverty. Health care insurance coverage was either private, Medicare, Medicaid, or none. Cox regression was used to model rates of survival. Results: A 3-way interaction between ethnicity, health care insurance coverage, and poverty was observed. Women of color inadequately insured and living in poor or near-poor neighborhoods in California were the most disadvantaged. Women of color adequately insured and who lived in such neighborhoods in California were also disadvantaged. The incomes of such women of color were typically lower than the incomes of non-Hispanic white women. Conclusions: Women of color with or without insurance coverage are disadvantaged in poor and near-poor neighborhoods of California. Such women may be less able to bare the indirect, direct, or uncovered costs of health care for breast cancer treatment

Mediation of the effects of living in extremely poor neighborhoods by health insurance: breast cancer care and survival in California, 1996 to 2011

Background: We examined the mediating effect of health insurance on poverty-breast cancer care and survival relationships and the moderating effect of poverty on health insurance-breast cancer care and survival relationships in California. Methods: Registry data for 6,300 women with breast cancer diagnosed between 1996 and 2000 and followed until 2011 on stage at diagnosis, surgeries, adjuvant treatments and survival were analyzed. Socioeconomic data were obtained for residences from the 2000 census to categorize neighborhoods: high poverty (30% or more poor), middle poverty (5%-29% poor) and low poverty (less than 5% poor). Primary payers or health insurers were Medicaid, Medicare, private or uninsured. Results: Evidence of survival mediation was observed for women with node negative breast cancer. The apparent effect of poverty disappeared in the presence of Medicare or private health insurance. Women who were so insured were advantaged on 8-year survival compared to the uninsured or those insured by Medicaid (OR = 1.89). Evidence of payer moderation by poverty was also observed for women with node negative breast cancer. The survival advantaging effect of Medicare or private insurance was stronger in low poverty (OR = 1.81) than it was in middle poverty (OR = 1.57) or in high poverty neighborhoods (OR = 1.16). This same pattern of mediated and moderated effects was also observed for early stage at diagnosis, shorter waits for adjuvant radiation therapy and for the receipt of sentinel lymph node biopsies. These findings are consistent with the theory that more facilitative social and economic capital is available in low poverty neighborhoods, where women with breast cancer may be better able to absorb the indirect and direct, but uncovered, costs of care. As for treatments, main protective effects as well as moderator effects indicative of protection, particularly in high poverty neighborhoods were observed for women with private health insurance. Conclusions: America’s multi-tiered health insurance system mediates the quality of breast cancer care. The system is inequitable and unjust as it advantages the well insured and the well to do. Recent health care reforms ought to be enacted in ways that are consistent with their federal legislative intent, that high quality health care be truly available to all

Breast Cancer among Women Living in Poverty: Better Care in Canada than in the United States

This historical study estimated the protective effects of a universally accessible, single-payer health care system versus a multipayer system that leaves many uninsured or underinsured by comparing breast cancer care of women living in high-poverty neighborhoods in Ontario and California between 1996 and 2011. Women in Canada experienced better care, particularly as compared with women who were inadequately insured in the United States. Women in Canada were diagnosed earlier (rate ratio [RR] = 1.12) and enjoyed better access to breast conserving surgery (RR = 1.48), radiation (RR = 1.60), and hormone therapies (RR = 1.78). Women living in high-poverty Canadian neighborhoods even experienced shorter waits for surgery (RR = 0.58) and radiation therapy (RR = 0.44) than did such women in the United States. Consequently, women in Canada were much more likely to survive longer. Regression analyses indicated that health insurance could explain most of the better care and better outcomes in Canada. Over this study’s 15-year time frame 31,500 late diagnoses, 94,500 suboptimum treatment plans, and 103,500 early deaths were estimated in high-poverty U.S. neighborhoods due to relatively inadequate health insurance coverage. Implications for social work practice, including advocacy for future reforms of U.S. health care, are discussed

The Healthy Mind, Healthy Mobility Trial: A Novel Exercise Program For Older Adults

BACKGROUND: More evidence is needed to conclude that a specific program of exercise and/or cognitive training warrants prescription for the prevention of cognitive decline. We examined the effect of a group-based standard exercise program for older adults, with and without dual-task training, on cognitive function in older adults without dementia. METHODS: We conducted a proof-of-concept, single-blinded, 26-wk randomized controlled trial whereby participants recruited from preexisting exercise classes at the Canadian Centre for Activity and Aging in London, Ontario, were randomized to the intervention group (exercise + dual-task [EDT]) or the control group (exercise only [EO]). Each week (2 or 3 d · wk(-1)), both groups accumulated a minimum of 50 min of aerobic exercise (target 75 min) from standard group classes and completed 45 min of beginner-level square-stepping exercise. The EDT group was also required to answer cognitively challenging questions while doing beginner-level square-stepping exercise (i.e., dual-task training). The effect of interventions on standardized global cognitive function (GCF) scores at 26 wk was compared between the groups using the linear mixed effects model approach. RESULTS: Participants (n = 44; 68% female; mean [SD] age: 73.5 [7.2] yr) had on average, objective evidence of cognitive impairment (Montreal Cognitive Assessment scores, mean [SD]: 24.9 [1.9]) but not dementia (Mini-Mental State Examination scores, mean [SD]: 28.8 [1.2]). After 26 wk, the EDT group showed greater improvement in GCF scores compared with the EO group (difference between groups in mean change [95% CI]: 0.20 SD [0.01-0.39], P = 0.04). CONCLUSIONS: A 26-wk group-based exercise program combined with dual-task training improved GCF in community-dwelling older adults without dementia

Risk of involuntary admission among first-generation ethnic minority groups with early psychosis: A retrospective cohort study using health administrative data

AimsEthnic minority groups often have more complex and aversive pathways to mental health care. However, large population-based studies are lacking, particularly regarding involuntary hospitalisation. We sought to examine the risk of involuntary admission among first-generation ethnic minority groups with early psychosis in Ontario, Canada.MethodsUsing health administrative data, we constructed a retrospective cohort (2009-2013) of people with first-onset non-affective psychotic disorder aged 16-35 years. This cohort was linked to immigration data to ascertain migrant status and country of birth. We identified the first involuntary admission within 2 years and compared the risk of involuntary admission for first-generation migrant groups to the general population. To control for the role of migrant status, we restricted the sample to first-generation migrants and examined differences by country of birth, comparing risk of involuntary admission among ethnic minority groups to a European reference. We further explored the role of migrant class by adjusting for immigrant vs refugee status within the migrant cohort. We also explored effect modification of migrant class by ethnic minority group.ResultsWe identified 15 844 incident cases of psychotic disorder, of whom 19% (n = 3049) were first-generation migrants. Risk of involuntary admission was higher than the general population in five of seven ethnic minority groups. African and Caribbean migrants had the highest risk of involuntary admission (African: risk ratio (RR) = 1.52, 95% CI = 1.34-1.73; Caribbean: RR = 1.58, 95% CI = 1.37-1.82), and were the only groups where the elevated risk persisted when compared to the European reference group within the migrant cohort (African: RR = 1.24, 95% CI = 1.04-1.48; Caribbean: RR = 1.29, 95% CI = 1.07-1.56). Refugee status was independently associated with involuntary admission (RR = 1.16, 95% CI = 1.02-1.32); however, this risk varied by ethnic minority group, with Caribbean refugees having an elevated risk of involuntary admission compared with Caribbean immigrants (RR = 1.72, 95% CI = 1.15-2.58).ConclusionsOur findings are consistent with the international literature showing increased rates of involuntary admission among some ethnic minority groups with early psychosis. Interventions aimed at improving pathways to care could be targeted at these groups to reduce disparities