Novel approaches to risk stratification to support malaria elimination: an example from Cambodia.

BACKGROUND: Accurate malaria stratification is essential for effective targeting of interventions but represents a particular challenge in pre-elimination settings. In these settings transmission is typically sufficiently low and spatially heterogeneous to warrant a need for estimates of malaria risk at sub-district or village level but is also likely to be sufficiently high to render the type of decision support systems appropriate to the final stages of malaria elimination impractical. In such a scenario it is arguably more feasible to strengthen existing passive malaria surveillance systems so that routinely generated case data can provide an effective basis for stratifying malaria risk. This paper explores the utility of routine malaria surveillance data for the stratification of malaria risk in Cambodia, where the target is malaria elimination by 2025. METHODS: A malaria information system (MIS) was developed to generate timely, routine data on temporal and spatial variations in malaria cases reported through public health facilities and village malaria workers (VMWs). The MIS was implemented across all malaria endemic districts in the country during 2010-11. In 2012 MIS data were extracted and assessed on the basis of coverage and completeness. Village-level incidence estimates for 2011 were generated using predefined data inclusion criteria. RESULTS: In 2011, the MIS covered 681 health facilities and 1,489 VMW villages; the overall completeness of monthly reporting was 82& and 97& for health facilities and VMWs respectively. Using these data it was possible to estimate malaria incidence for 89& of villages covered by the MIS. The resulting stratification highlights the highly heterogeneous nature of malaria transmission in Cambodia and underlines the importance of village-level data for effective targeting of interventions, including VMWs. Challenges associated with implementing the MIS and the implications of these for developing viable and sustainable MIS in Cambodia and elsewhere are discussed. CONCLUSIONS: This study demonstrates the operational feasibility of introducing a system to routinely generate village level malaria case data in Cambodia. Although resulting incidence estimates are subject to various limitations and biases the data provide an objective, repeatable basis for a dynamic system of stratification which is appropriate for guiding the transition between malaria pre-elimination and elimination phases.

Evaluation of community-based systems for the surveillance of day three-positive Plasmodium falciparum cases in Western Cambodia.

BACKGROUND: Delayed clearance of Plasmodium falciparum parasites is used as an operational indicator of potential artemisinin resistance. Effective community-based systems to detect P. falciparum cases remaining positive 72 hours after initiating treatment would be valuable for guiding case follow-up in areas of known resistance risk and for detecting areas of emerging resistance. METHODS: Systems incorporating existing networks of village malaria workers (VMWs) to monitor day three-positive P. falciparum cases were piloted in three provinces in western Cambodia. Quantitative and qualitative data were used to evaluate the wider feasibility and sustainability of community-based surveillance of day three-positive P. falciparum cases. RESULTS: Of 294 day-3 blood slides obtained across all sites (from 297 day-0 positives), 63 were positive for P. falciparum, an overall day-3 positivity rate of 21%. There were significant variations in the systems implemented by different partners. Full engagement of VMWs and health centre staff is critical. VMWs are responsible for a range of individual tasks including preparing blood slides on day-0, completing forms, administering directly observed therapy (DOT) on days 0-2, obtaining follow-up slides on day-3 and transporting slides and paperwork to their supervising health centre. When suitably motivated, unsalaried VMWs are willing and able to produce good quality blood smears and achieve very high rates of DOT and day-3 follow-up. CONCLUSIONS: Community-based surveillance of day-3 P. falciparum cases is feasible, but highly intensive, and as such needs strong and continuous support, particularly supervision and training. The purpose and role of community-based day-3 surveillance should be assessed in the light of resource requirements; scaling-up would need to be systematic and targeted, based on clearly defined epidemiological criteria. To be truly comprehensive, the system would need to be extended beyond VMWs to other public and private health providers.

The conditional indirect effect model of women's union participation: the moderating effect of perceived union tolerance for sexual harassment.

We tested a theoretically trimmed model of union participation presented by Tetrick, Shore, McClurg, and Vandenberg (2007), in which perceived union instrumentality is expected to influence participation through perceived union support. This testing was accomplished as a precursor to testing a conditional indirect effect model of women's participation--in which perceived union tolerance for sexual harassment was expected to moderate the influence of perceived support on willingness to participate in union activities. In a sample of 326 women from multiple unions, we found support for the conditional model; the influence of perceived instrumentality on willingness to participate through perceived support was moderated by perceived tolerance for harassment; specifically, the influence through perceived support was weak when perceived tolerance was high. The implications of our results are discussed in reference to need support and women's participation.

The potency of one-to-one contact with union leaders: enhancing self-efficacy to become a union steward.

Finding ways to encourage union members to become union leaders is a perennial problem for unions. P. A. Roby originally found the importance of one-to-one contact with union leaders in becoming a union steward. In this study, the authors examined stewards' descriptions of their one-to-one contact with a union leader before becoming a steward. They sought to (a) replicate and strengthen Roby's findings, (b) explore one-to-one contact as a self-efficacy (i.e., confidence) enhancing experience, and (c) identify self-efficacy enhancement modes to strengthen the potency of the contact experience. The results from a mostly open-ended questionnaire of 44 stewards mirrored Roby's findings. The results indicated that self-efficacy enhancement modes were present in the one-to-one contact experience and that the enhancement modes were related to self-efficacy to become a steward. Two of the modes, verbal encouragement and emotional inhibition, were independently related to self-efficacy. The authors suggest how leaders could increase the potency of their contact with members as a means of encouraging members to become stewards.

Adulthood Social Class and Union Interest: A First Test of a Theoretical Model.

A serial mediation model of union interest was tested. Based on theoretical notes provided by Mellor and Golay (in press), adulthood social class was positioned as a predictor of willingness to join a labor union, with success/failure attributions at work and willingness to share work goals positioned as intervening variables. Data from U.S. nonunion employees (N = 560) suggested full mediation after effects were adjusted for childhood social class. In sequence, adulthood social class predicted success/failure attributions at work, success/failure attributions at work predicted willingness to share work goals, and willingness to share work goals predicted willingness to join. Implications for socioeconomic status (SES) research and union expansion are discussed.

Individual unionization decisions: a multilevel model of cost-benefit influences.

An important part of the unionization process is predicting the individual's vote for or against union representation. We proposed and tested a multilevel model based on the relative importance of costs and benefits of representation. Regression statistics from within-person analyses were used to show the influence of perceived costs and benefits on judgment policies about intent to vote in a representation election. Using these statistics as outcome variables, between--person analyses were used to show the influence of decision frame on cost-benefit influences, in which framing a vote as one for or against the union was conceived as a contextual variable in an election. Results were used to extend prior unionization research and to suggest how employers and unions may attend to framing effects in an election.

"I couldn't have seen it coming": the impact of negative self-relevant outcomes on retrospections about foreseeability.

We examined a phenomenon related to hindsight bias, specifically, retrospective judgements about the foreseeability of an outcome. We predicted that negative, self-relevant outcomes would be judged as less foreseeable by the recipient of the outcome than by others, unlike either positive outcomes or outcomes that are not self-relevant. In the context of a "stock market decision-making game", the hypothetical stock selected by one of two players showed an extreme increase or decrease. As predicted, the player who received an extreme negative outcome reported that this outcome was less foreseeable than did the opponent and an observer, for whom the outcome was less self-relevant. For no other kind of outcome was there a difference between the recipient of an outcome, the opponent, and the observer. The findings have several implications, including the possibility that hindsight bias should be considered as a special case of retrospective foreseeability.