A partial score test for difference among heterogeneous populations

In event time data analysis, comparisons between distributions are made by the logrank test. When the data appear to contain crossing hazards phenomena, nonparametric weighted logrank statistics are usually suggested to accommodate different-weighted functions to increase the power. However, the gain in power by imposing different weights has its limits since differences before and after the crossing point may balance each other out. In contrast to the weighted logrank tests, we propose a score-type statistic based on the semiparametric-, heteroscedastic-hazards regression model of Hsieh [2001. On heteroscedastic hazards regression models: theory and application. J. Roy. Statist. Soc. Ser. B 63, 63–79.], by which the nonproportionality is explicitly modeled. Our score test is based on estimating functions derived from partial likelihood under the heteroscedastic model considered herein. Simulation results show the benefit of modeling the heteroscedasticity and power of the proposed test to two classes of weighted logrank tests (including Fleming–Harrington's test and Moreau's locally most powerful test), a Renyi-type test, and the Breslow's test for acceleration. We also demonstrate the application of this test by analyzing actual data in clinical trials.     

Residential Remittances and Food Security in the Upper West Region of Ghana

In recent years, out migration from the Upper West Region to the southern belt of Ghana for farming has become commonplace. The natural question that has arisen is: what is the potential impact of remittances from this migration pattern on food security in the region? Using multivariate ordered logistic regression this study assesses the linkage between remittances and household food security (derived using the HFIAS) among urban and rural households (n=1,438) in the region. The findings show that urban remittance‐receiving households and rural remittance and non‐remittance receiving households were more likely (OR=2.44, p<0.05; OR=2.46, p<0.001; and OR=1.49, p<0.1, respectively) to report being more severely food‐insecure than urban non‐remittance receiving households. The findings demonstrate that household strategies such as migration and remittances on their own are not sufficient to ameliorate the precarious food insecurity situation of the region. The study calls for development of alternative livelihoods in the region.     

Competing Priorities: Partner-Specific Relationship Characteristics and Motives for Condom Use Among At-Risk Young Adults

Condoms protect against human immunodeficiency virus (HIV)/sexually transmitted infections (STIs) and unintended pregnancy and are essential to sexual health efforts targeting young adults, who are disproportionately affected by both outcomes. Understanding condom use motives is critical to increasing condom use. Research in this area is limited, particularly regarding the roles of partners and relationship factors. Using a longitudinal sample of 441 young adults and 684 reported partnerships we examined associations between relationship factors and condom use motives (pregnancy prevention, disease prevention, or dual protection). Simultaneous multilevel models identified variables associated with motives; level-specific models identified the levels (individual, partnership, time) variables impacted motives. Participants reported choosing condoms for pregnancy prevention, disease prevention, and dual protection in 51%, 17%, and 33% of partnerships, respectively. Partner-specific factors varied, to a differing degree, across the three levels. Seven variables (duration, condom self-efficacy, commitment, sexual decision-making, power, and vulnerability to harm [HIV/STIs] and pregnancy) distinguished condom use motives. The level of this association varied but was most pronounced at the partner and individual levels. Researchers and practitioners should consider the impact of both individual- and partner-level factors on condom use motives, in both research and sexual health programs.     

Even the ‘Rich’ are Vulnerable: Multiple Shocks and Downward Mobility in Rural Uganda

Poverty data rarely capture processes of change, limiting our ability to understand poverty trajectories at the individual or household levels. This article uses a household survey, village‐level participatory studies and indepth life‐history interviews to examine people's poverty trajectories and to identify what drives and maintains chronic poverty. Composite shocks can propel previously non‐poor households into severe and long‐term poverty. Poverty is hard to escape, and people born into chronically poor households find few opportunities for accumulation and wealth creation. The analysis highlights the importance of poverty interrupters, including the end of conflict and the re‐integration of internally displaced people, and suggests that state‐led interventions would be needed to provide real opportunities to the chronically poor.     

The Influence of Heuristics on Psychological Science: A Case Study of Research on Creativity

Research heuristics—implicit rules used to guide work on a scientific problem—are explored for their role in guiding psychological research. Work on the psychology of creativity is used to illustrate how heuristics have guided research. We examine the influence of three heuristics: the trilogy-of-mind heuristic, the emotions-as-moods heuristic, and the analysis-of-variance heuristic. This analysis of multiple heuristics provides a new way to understand the state of research on creativity. In the discussion, the analysis is extended to other heuristics and to how heuristics may help as well as hinder innovative research.     

Effect of COVID-19 on Household Food Insecurity and Poverty: Evidence from Ghana

Social Indicators Research - Following the outbreak of COVID-19 and its heavy toll on the global community and humanity, a fierce debate on the pandemic and Sustainable Development Goals (SDGs)...