Analysis of combined probability and nonprobability samples: A simulation evaluation and application to a teen smoking behavior survey.

In scientific studies with low-prevalence outcomes, probability sampling may be supplemented by nonprobability sampling to boost the sample size of desired subpopulation while remaining representative to the entire study population. To utilize both probability and nonprobability samples appropriately, several methods have been proposed in the literature to generate pseudo-weights, including ad-hoc weights, inclusion probability adjusted weights, and propensity score adjusted weights. We empirically compare various weighting strategies via an extensive simulation study, where probability and nonprobability samples are combined. Weight normalization and raking adjustment are also considered. Our simulation results suggest that the unity weight method (with weight normalization) and the inclusion probability adjusted weight method yield very good overall performance. This work is motivated by the Buckeye Teen Health Study, which examines risk factors for the initiation of smoking among teenage males in Ohio. To address the low response rate in the initial probability sample and low prevalence of smokers in the target population, a small convenience sample was collected as a supplement. Our proposed method yields estimates very close to the ones from the analysis using only the probability sample and enjoys the additional benefit of being able to track more teens with risky behaviors through follow-ups.

'Know-Can' gap: gap between knowledge and skills related to childhood diarrhoea and pneumonia among frontline workers in rural Uttar Pradesh, India.

OBJECTIVES: In India, frontline workers (FLWs) - public accredited social health activists (ASHAs) and private rural medical providers (RMPs) - are important for early detection and treatment of childhood diarrhoea and pneumonia. This cross-sectional study aims to measure knowledge and skills, and the gap between the two ('know-can' gap), regarding assessment of childhood diarrhoea with dehydration and pneumonia among FLWs, and to explore factors associated with them. METHODS: We surveyed 473 ASHAs and 447 RMPs in six districts of Uttar Pradesh. We assessed knowledge and skills using face-to-face interviews and video vignettes, respectively, about key signs of both conditions. The 'know-can' gap corresponds to absent skills among FLWs with correct knowledge. We used logistic regression to identify the correlates of knowledge and skills. RESULTS: FLWs' correct knowledge ranged from 23% to 48% for dehydration signs and 27% to 37% for pneumonia signs. Their skills ranged from 3% to 42% for dehydration and 3% to 18% for pneumonia. There was a significant 'know-can' gap in all the signs, except 'sunken eyes'. Training and supervisory support was associated with better knowledge and skills for diarrhoea with dehydration, but only better knowledge for pneumonia. CONCLUSIONS: FLWs are crucial to the Indian health system, and high-quality FLW services are necessary for continued progress against under-five deaths. The gap between FLWs' knowledge and skills warrants immediate attention. In particular, our results suggest that knowledge-focused trainings are insufficient for FLWs to convert knowledge into appropriate assessment skills.

OBJECTIFS: En Inde, les travailleurs de première ligne (TPL) - activistes de la santé sociale accrédités par le public (ASSAP) et prestataires médicaux ruraux privés (PMRP) - sont importants pour la détection et le traitement précoces de la diarrhée et de la pneumonie infantiles. Cette étude transversale vise à mesurer les connaissances et les compétences, et l'écart entre les deux (écart ''savoir-pouvoir''), en ce qui concerne l'évaluation de la diarrhée infantile avec déshydratation et la pneumonie chez les TPL et à explorer les facteurs qui leur sont associés. MÉTHODES: Nous avons mené une enquête sur 473 ASSAP et 447 PMRP dans six districts de l'Uttar Pradesh. Nous avons évalué les connaissances et les compétences à l'aide d'entretiens de face à face et de vignettes vidéo, respectivement, sur les signes clés des deux conditions. L'écart «savoir-pouvoir¼ correspond à des compétences absentes parmi les TPL ayant des connaissances correctes. Nous avons utilisé la régression logistique pour identifier les corrélats des connaissances et des compétences. RÉSULTATS: Les connaissances correctes des TPL variaient de 23% à 48% pour les signes de déshydratation, 27% à 37% pour les signes de pneumonie. Leurs compétences variaient de 3% à 42% pour la déshydratation et de 3% à 18% pour la pneumonie. Il y avait un écart important dans le «savoir-pouvoir¼ pour tous les signes, à l'exception des «yeux enfoncés¼. La formation et le soutien à la supervision étaient associés à de meilleures connaissances et compétences pour la diarrhée avec déshydratation, mais seulement à de meilleures connaissances pour la pneumonie. CONCLUSIONS: Les TPL sont cruciaux pour le système de santé indien, et des services de TPL de haute qualité sont nécessaires pour continuer à lutter contre les décès d'enfants de moins de cinq ans. L'écart entre les connaissances et les compétences des TPL mérite une attention immédiate. En particulier, nos résultats suggèrent que les formations axées sur les connaissances sont insuffisantes pour que les TPL convertissent les connaissances en compétences d'évaluation appropriées.

The Feeding Infants and Toddlers Study (FITS) 2016: Study Design and Methods.

Background: Diet and feeding patterns during the infant, toddler, and preschool years affect nutrient adequacy or excess during critical developmental periods. Understanding food consumption, feeding practices, and nutrient adequacy or excess during these periods is essential to establishing appropriate recommendations aimed at instilling healthy eating behaviors in children. Objective: The objective of the 2016 Feeding Infants and Toddlers Study (FITS 2016) was to update our knowledge on the diets and feeding patterns of young children and to provide new data in related areas such as feeding behaviors, sleep, physical activity, and screen use. This article describes the study design, data collection methods, 24-h dietary recall (24-h recall) protocol, and sample characteristics of FITS 2016. Methods: FITS 2016 is a cross-sectional study of caregivers of children aged <4 y living in the 50 states and Washington, DC. Data collection occurred between June 2015 and May 2016. A recruitment interview (respondent and child characteristics, feeding practices, physical activity, screen use, and sleep habits) was completed by telephone or online. This was followed by a feeding practices questionnaire and the 24-h recall conducted by telephone. A second 24-h recall was collected for a random subsample of 25% of the total sampled population. Results: Among the 4830 recruited households with an age-eligible child, 3248 (67%) completed the 24-h recall. The respondents were more likely to be white, less likely to be Hispanic, and more highly educated than the US population of adults in households with a child <4 y of age. The sample was subsequently calibrated and weighted, and the distribution of respondents was compared with known population distributions. Conclusions: FITS 2016 provides data based on sound methods that can inform researchers, policymakers, and practitioners about the food and nutrient intakes of young children. New findings may also be compared with previous FITS studies.

The relationship between health worker stigma and uptake of HIV counseling and testing and utilization of non-HIV health services: the experience of male and female sex workers in Kenya.

The barrier HIV-stigma presents to the HIV treatment cascade is increasingly documented; however less is known about female and male sex worker engagement in and the influence of sex-work stigma on the HIV care continuum. While stigma occurs in all spheres of life, stigma within health services may be particularly detrimental to health seeking behaviors. Therefore, we present levels of sex-work stigma from healthcare workers (HCW) among male and female sex workers in Kenya, and explore the relationship between sex-work stigma and HIV counseling and testing. We also examine the relationship between sex-work stigma and utilization of non-HIV health services. A snowball sample of 497 female sex workers (FSW) and 232 male sex workers (MSW) across four sites was recruited through a modified respondent-driven sampling process. About 50% of both male and female sex workers reported anticipating verbal stigma from HCW while 72% of FSW and 54% of MSW reported experiencing at least one of seven measured forms of stigma from HCW. In general, stigma led to higher odds of reporting delay or avoidance of counseling and testing, as well as non-HIV specific services. Statistical significance of relationships varied across type of health service, type of stigma and gender. For example, anticipated stigma was not a significant predictor of delay or avoidance of health services for MSW; however, FSW who anticipated HCW stigma had significantly higher odds of avoiding (OR = 2.11) non-HIV services, compared to FSW who did not. This paper adds to the growing evidence of stigma as a roadblock in the HIV treatment cascade, as well as its undermining of the human right to health. While more attention is being paid to addressing HIV-stigma, it is equally important to address the key population stigma that often intersects with HIV-stigma.

Nonmedical use of prescription drugs in the European Union.

BACKGROUND: Nonmedical prescription drug use (NMPDU) refers to the self-treatment of a medical condition using medication without a prescriber's authorization as well as use to achieve euphoric states. This article reports data from a cross-national investigation of NMPDU in five European Countries, with the aim to understand the prevalence and characteristics of those engaging in NMPDU across the EU. METHODS: A parallel series of self-administered, cross-sectional, general population surveys were conducted in 2014. Data were collected using multi-stage quota sampling and then weighted using General Exponential Model. A total of 22,070 non-institutionalized participants, aged 12 to 49 years, in 5 countries: Denmark, Germany, Great Britain, Spain, and Sweden. Lifetime and past-year nonmedical use of prescription medications such as stimulants, opioids, and sedatives were ascertained via a modified version of the World Health Organization's Composite International Diagnostic Interview. Information about how the medications were acquired for NMPDU were also collected from the respondent. RESULTS: Lifetime and past-year prevalence of nonmedical prescription drug use was estimated for opioids (13.5 and 5.0 %), sedatives (10.9 and 5.8 %), and stimulants (7.0 and 2.8 %). Germany exhibited the lowest levels of NMPDU, with Great Britain, Spain, and Sweden having the highest levels. Mental and sexual health risk factors were associated with an increased likelihood of past-year nonmedical prescription drug use. Among past-year users, about 32, 28, and 52 % of opioid, sedative, and stimulant nonmedical users, respectively, also consumed illicit drugs. Social sources (sharing by friends/family) were the most commonly endorsed methods of acquisition, ranging from 44 % (opioids) to 62 % (sedatives). Of interest is that Internet pharmacies were a common source of medications for opioids (4.1 %), stimulants (7.6 %), and sedatives (2.7 %). CONCLUSIONS: Nonmedical prescription drug use was reported across the five EU countries we studied, with opioids and sedatives being the most prevalent classes of prescription psychotherapeutics. International collaborations are needed for continued monitoring and intervention efforts to target population subgroups at greatest risk for NMDU.

Measuring treatment coverage for neglected tropical disease control programs: analysis of a survey design.

Monitoring of treatment coverage following mass drug administration is essential to ensure program success. Coverage results reported by drug administrators are often validated by using population surveys. This study evaluates the design of a multistage cluster sample survey conducted in 2007-2008 and implemented at the district level to assess drug coverage in the 4 African countries of Burkina Faso, Ghana, Niger, and Uganda. Estimates of precision of coverage were calculated, and factors contributing to the observed variance were analyzed. Precision of ±5 percentage points was obtained in 39% (n = 12) of cases, and precision of ±10 percentage points was obtained in 77% (n = 24) of cases. The factor having the largest impact on the actual precision obtained in these surveys was the high level of clustering, the impact of which is incorporated in the design effect. Key recommendations are made for the design and analysis of future surveys; guidelines are presented for thinking through the number of clusters that should be selected and how a cluster should be designed.

Differences between RDD telephone and ABS mail survey design: coverage, unit nonresponse, and measurement error.

Using list-assisted random digit dialing (RDD) with telephone data collection and address-based sampling (ABS) with mail questionnaires are two survey designs that yield probability based inference, yet they are so different that they can yield entirely different results. The 2007 Health Information National Trends Survey (HINTS) provides a unique opportunity to evaluate the effect of these different designs on a variety of survey estimates and, even more importantly, the effect on individual sources of survey error. Understanding the difference in error structure between the two designs is important to survey practitioners in order to select the optimum design, and to data users who can anticipate which results may be affected and how. We first compared estimates between the two designs and then estimated the different sources of error. In addition to identified differences in estimates, we found that for some estimates the two designs can yield similar results merely due to the effect of similar biases. The error components were quite different between the two designs--while the ABS design yields almost complete coverage of the population compared to the RDD design, it was subjected to substantially higher nonresponse bias.

Employee assistance program services for intimate partner violence and client satisfaction with these services.

OBJECTIVE: To describe intimate partner violence (IPV) services available through employee assistance programs (EAPs) and determine women's satisfaction with these services. METHODS: A mixed-methods study consisting of semistructured telephone interviews with 28 EAPs about IPV-related services and a national web-based survey of 1765 women regarding their interactions with EAPs when seeking IPV-related assistance. Data were collected in the fall of 2008. RESULTS: EAPs provide fairly extensive services to individuals experiencing IPV. Satisfaction with EAP services for IPV was significantly associated with annual income and the type of help received from the EAP, but not with type of IPV experienced. EAP representatives described challenges with accurately identifying IPV victims and women expressed concerns with confidentiality. CONCLUSIONS: Future efforts to enhance the ability of EAPs to respond effectively to IPV should address confidentially and strengthen how IPV-related assistance is delivered.