Engaging stakeholders in pharmacoepidemiology research: Current state and recommendations.

PURPOSE: Given current efforts to enhance patient-centered care and shared decision-making, the International Society of Pharmacoepidemiology Workgroup on Patient Engagement assessed patient and other stakeholder engagement in pharmacoepidemiology research and provides recommendations for the field. METHODS: A systematic review used MEDLINE and EMBASE to identify published literature from 2005 to 2016 addressing how stakeholders-patients, caregivers, and others-assisted researchers conducting pharmacoepidemiologic research. Three pairs of Workgroup members screened titles and abstracts to select articles for full-text review and analysis. Two Workgroup members abstracted the following data: research focus, characterization and role of stakeholders, and type(s) of engagement strategy employed. Data were summarized descriptively. RESULTS: We identified 5717 references for abstract screening. Of these, 69 met the criteria for full-text screening, and 11 were selected for data abstraction. Of these 11 studies, seven focused on the development of a research agenda and eight had stakeholders react or advise on an aspect of the study. Although patients were the most commonly identified stakeholders, advocacy groups and health care professionals were also frequently identified. Some studies reported the engagement of other stakeholders, including local government or policy experts. Engagement strategies varied, with five studies using more than one strategy. Studies often did not indicate the involvement of stakeholders in developing the study design or with implementation. CONCLUSIONS: Currently, few pharmacoepidemiology publications mention patient or other stakeholder engagement in the design, analysis, or reporting of research. This suggests that there are opportunities to expand stakeholder engagement and/or increase the transparency of reporting stakeholder engagement.

Dynamics of an ant-ant obligate mutualism: colony growth, density dependence and frequency dependence.

In insect societies, worker vs. queen development (reproductive caste) is typically governed by environmental factors, but many Pogonomyrmex seed-harvester ants exhibit strict genetic caste determination, resulting in an obligate mutualism between two reproductively isolated lineages. Same-lineage matings produce fertile queens while alternate-lineage matings produce sterile workers. Because new virgin queens mate randomly with multiple males of each lineage type, and both worker and queen phenotypes are required for colony growth and future reproduction, fitness is influenced by the relative frequency of each lineage involved in the mutualistic breeding system. While models based solely on frequency-dependent selection predict the convergence of lineage frequencies towards equal (0.5/0.5), we surveyed the lineage ratios of 49 systems across the range of the mutualism and found that the global lineage frequency differed significantly from equal. Multiple regression analysis of our system survey data revealed that the density and relative frequency of one lineage decreases at lower elevations, while the frequency of the alternate lineage increases with total colony density. While the production of the first worker cohort is largely frequency dependent, relying on the random acquisition of worker-biased sperm stores, subsequent colony growth is independent of lineage frequency. We provide a simulation model showing that a net ecological advantage held by one lineage can lead to the maintenance of stable but asymmetric lineage frequencies. Collectively, these findings suggest that a combination of frequency-dependent and frequency-independent mechanisms can generate many different localized and independently evolving system equilibria.

The potential for gene flow in a dependent lineage system of a harvester ant: fair meiosis in the F1 generation.

We investigated the potential for gene flow in a dependent lineage (DL) system of the harvester ant Pogonomyrmex. Each DL system is composed of 2 reproductively isolated lineages that are locked in an obligate mutualism. The genetic components that produce the worker phenotype are acquired by hybridizing with the partner lineage. In the mating flight, queens of both lineages mate with multiple males from each lineage. During colony growth and reproduction, eggs fertilized by partner-lineage sperm produce F(1) hybrid workers with interlineage genomes, whereas eggs fertilized by same-lineage sperm result in the development of new queens with intralineage genomes. New males are typically produced from unfertilized eggs laid by the pure-lineage queen but in her absence may be produced by interlineage F(1) workers. We investigated the potential for interlineage gene flow in this system using 2 classes of lineage-specific nuclear markers to identify hybrid genome combinations. We confirmed the production of viable interlineage F(1) reproductive females in field colonies, the occurrence of which is associated with the relative frequencies of each lineage in the population: interlineage F(1) queens occurred only in the rare lineage of the population with dramatically skewed lineage frequencies. In laboratory colonies, we detected fair meiosis in interlineage F(1) workers leading to the production of viable and haploid interlineage F(2) males. We conclude that the genomes of each lineage recombine freely, suggesting that extrinsic postzygotic selection maintains the integrity of each lineage genome. We compare our findings with those of the H1/H2 DL system.