Now showing 1 - 3 of 3
ItemComparison of three methods for ascertainment of contact information relevant to respiratory pathogen transmission in encounter networksMcCaw, JM ; Forbes, K ; Nathan, PM ; Pattison, PE ; Robins, GL ; Nolan, TM ; McVernon, J (BMC, 2010-06-10)BACKGROUND: Mathematical models of infection that consider targeted interventions are exquisitely dependent on the assumed mixing patterns of the population. We report on a pilot study designed to assess three different methods (one retrospective, two prospective) for obtaining contact data relevant to the determination of these mixing patterns. METHODS: 65 adults were asked to record their social encounters in each location visited during 6 study days using a novel method whereby a change in physical location of the study participant triggered data entry. Using a cross-over design, all participants recorded encounters on 3 days in a paper diary and 3 days using an electronic recording device (PDA). Participants were randomised to first prospective recording method. RESULTS: Both methods captured more contacts than a pre-study questionnaire, but ascertainment using the paper diary was superior to the PDA (mean difference: 4.52 (95% CI 0.28, 8.77). Paper diaries were found more acceptable to the participants compared with the PDA. Statistical analysis confirms that our results are broadly consistent with those reported from large-scale European based surveys. An association between household size (trend 0.14, 95% CI (0.06, 0.22), P < 0.001) and composition (presence of child 0.37, 95% CI (0.17, 0.56), P < 0.001) and the total number of reported contacts was observed, highlighting the importance of sampling study populations based on household characteristics as well as age. New contacts were still being recorded on the third study day, but compliance had declined, indicating that the optimal number of sample days represents a trade-off between completeness and quality of data for an individual. CONCLUSIONS: The study's location-based reporting design allows greater scope compared to other methods for examining differences in the characteristics of encounters over a range of environments. Improved parameterisation of dynamic transmission models gained from work of this type will aid in the development of more robust decision support tools to assist health policy makers and planners.
ItemStructural Logic of Intraorganizational NetworksRank, ON ; Robins, GL ; Pattison, PE (INFORMS, 2010-05-01)In this study we examine the structural logic underlying complex intraorganizational networks. Drawing on different propositions about structural regularities in networks and using a comparative case study, we empirically investigate the structural logic of collaborative networks for the strategic decision process in two German corporations. In both organizations, data were gathered on cooperative relationships between all managers belonging to the top two management levels. We model structural regularities at the dyadic and the extradyadic level by applying a class of multivariate exponential random graph models. Our findings contribute to the existing literature in three ways: (1) Although networks are particularly likely to exhibit some types of structural regularities (e.g., reciprocity and transitivity), there are other relational forms such as cycles that seem to be of limited relevance. (2) Structural regularities are not limited to a single type of relation but may comprise instrumental and affective relational ties simultaneously. (3) An organization's formal cooperation structure has surprisingly limited influence on the structural patterns of cooperation, whereas friendship ties are embedded in managers' regular interaction patterns in many different ways.