Continuing Contributions of Field Epidemiology Training Programs to Global COVID-19 Response.

We documented the contributions of Field Epidemiology Training Program (FETP) trainees and graduates to global COVID-19 preparedness and response efforts. During February-July 2021, we conducted surveys designed in accordance with the World Health Organization's COVID-19 Strategic Preparedness and Response Plan. We quantified trainee and graduate engagement in responses and identified themes through qualitative analysis of activity descriptions. Thirty-two programs with 2,300 trainees and 7,372 graduates reported near-universal engagement across response activities, particularly those aligned with the FETP curriculum. Graduates were more frequently engaged than were trainees in pandemic response activities. Common themes in the activity descriptions were epidemiology and surveillance, leading risk communication, monitoring and assessment, managing logistics and operations, training and capacity building, and developing guidelines and protocols. We describe continued FETP contributions to the response. Findings indicate the wide-ranging utility of FETPs to strengthen countries' emergency response capacity, furthering global health security.

Field epidemiology training programs contribute to COVID-19 preparedness and response globally.

BACKGROUND: Field epidemiology training programs (FETPs) have trained field epidemiologists who strengthen global capacities for surveillance and response to public health threats. We describe how FETP residents and graduates have contributed to COVID-19 preparedness and response globally. METHODS: We conducted a cross-sectional survey of FETPs between March 13 and April 15, 2020 to understand how FETP residents or graduates were contributing to COVID-19 response activities. The survey tool was structured around the eight Pillars of the World Health Organization's (WHO) Strategic Preparedness and Response Plan for COVID-19. We used descriptive statistics to summarize quantitative results and content analysis for qualitative data. RESULTS: Among 88 invited programs, 65 (74%) responded and indicated that FETP residents and graduates have engaged in the COVID-19 response across all six WHO regions. Response efforts focused on country-level coordination (98%), surveillance, rapid response teams, case investigations (97%), activities at points of entry (92%), and risk communication and community engagement (82%). Descriptions of FETP contributions to COVID-19 preparedness and response are categorized into seven main themes: conducting epidemiological activities, managing logistics and coordination, leading risk communication efforts, providing guidance, supporting surveillance activities, training and developing the workforce, and holding leadership positions. CONCLUSIONS: Our findings demonstrate the value of FETPs in responding to public health threats like COVID-19. This program provides critical assistance to countries' COVID-19 response efforts but also enhances epidemiologic workforce capacity, public health emergency infrastructure and helps ensure global health security as prescribed in the WHO's International Health Regulations.

South Africa field epidemiology training program: developing and building applied epidemiology capacity, 2007-2016.

In 2007, South Africa (SA) launched a field epidemiology training program (SAFETP) to enhance its capacity to prevent, detect, and respond to public health threats through training in field epidemiology. The SAFETP began as a collaboration between the SA National Department of Health (NDOH), National Institute for Communicable Diseases (NICD), and the University of Pretoria (UP), with technical and financial support from the U.S. Centers for Disease Control and Prevention (CDC). In 2010, the CDC in collaboration with the NICD, established a Global Disease Detection (GDD) Center in SA, and the SAFETP became a core activity of the GDD center. Similar to other FETPs globally, the SAFETP is a 2-year, competency-based, applied epidemiology training program, following an apprenticeship model of 'learn by doing'. SAFETP residents spend approximately 25% of the training in classroom-based didactic learning activities, and 75% in field activities to attain core competencies in epidemiology, biostatistics, outbreak investigation, scientific communication, surveillance evaluation, teaching others, and public health leadership. Residents earn a Master's in Public Health (MPH) degree from UP upon successfully completing a planned research study that serves as a mini-dissertation.Since 2007, SAFETP has enrolled an average of 10 residents each year and, in 2017, enrolled its 11th cohort. During the first 10 years of the program, 98 residents have been enrolled, 89% completed the 2-year program, and of these, 76 (87%) earned an MPH degree. Of those completing the program, 88% are employed in the public health sector, and work at NICD, NDOH, Provincial Health Departments, foreign health institutions, or non-governmental organizations. In the first 10 years of the program, the combined outputs of trainees included over 130 outbreak investigations, more than 150 abstracts presented at national and international scientific conferences, more than 80 surveillance system evaluations, and more than 45 manuscripts published in peer-reviewed scientific journals. The SAFETP is having an impact in building epidemiology capacity for public health in South Africa. Developing methods to directly link and measure the impact of the program is planned for the future.

Predictors of male condom use among sexually active heterosexual young women in South Africa, 2012.

BACKGROUND: In South Africa, young women are at disproportionate risk of HIV infection with about 2363 new infections per week in 2015. Proper condom use is one of the most effective HIV/AIDS prevention strategies among sexually active persons. Understanding factors associated with male condom use in this key population group is important to curb the spread of HIV. This study determined practices and predictors of male condom use among sexually active young women in South Africa. METHODS: The 2012 National HIV Communication Survey measured the extent of exposure to communication activities for HIV prevention among men and women aged 16-55 years in South Africa. We performed a secondary data analysis on a subset of this survey, focussing on 1031 women aged 16-24 years who reported having had sex in the past 12 months. We determined predictors of male condom use using the unconditional multivariable logistic regression model. RESULTS: Of the 1031 young women, 595 (57.8%) reported using a male condom at last sex, 68.4% in women aged 16-19 years and 54.5% in women aged 20-24 years (p < 0.001). Delayed sexual debut [20 years or above] (Adjusted Odds Ratio [aOR] 2.1, 95% CI: 1.2 to 3.7, p = 0.006); being a student (aOR 1.6, 95% CI: 1.2 to 2.3, p = 0.005); and exposure to HIV communication programmes (aOR 3.1, 95% CI: 1.2 to 8.6, p = 0.025) were significantly associated with male condom use at last sex. CONCLUSION: Male condom use was a common practice among young women and was associated with delayed sexual debut and exposure to HIV communication programmes. Behavioral interventions and HIV communication programmes should therefore encourage young women to delay initiation of sex and promote usage of male condoms.

Secondary Infections with Ebola Virus in Rural Communities, Liberia and Guinea, 2014-2015.

Persons who died of Ebola virus disease at home in rural communities in Liberia and Guinea resulted in more secondary infections than persons admitted to Ebola treatment units. Intensified monitoring of contacts of persons who died of this disease in the community is an evidence-based approach to reduce virus transmission in rural communities.

Risk factors for tuberculosis smear non-conversion in Eden district, Western Cape, South Africa, 2007-2013: a retrospective cohort study.

BACKGROUND: Tuberculosis (TB) continues to be a major global health problem. While progress has been made to improve TB cure rates, South Africa's 76 % smear-positive pulmonary TB (PTB) case cure rate remains below the WHO target of 85 %. We report on the trends of TB smear non-conversion and their predictors at the end of an intensive phase of treatment, and how this impacted on treatment outcomes of smear-positive PTB cases in Eden District, Western Cape Province, South Africa. METHODS: Routinely collected, retrospective data of smear-positive PTB cases from the electronic TB register in Eden District between 2007 and 2013 was extracted. Non-conversion was defined as persistent sputum smear-positive PTB cases at the end of the two or three month intensive phase of treatment. Chi-square test for linear trend and simple linear regression analysis were used to analyse the change in percentages and slope of TB smear non-conversion rates over time. Risk factors for TB non-conversion, and their impact on treatment outcomes, were evaluated using logistic regression models. RESULTS: Of 12,742 total smear-positive PTB cases included in our study, 12.8 % (n = 1627) did not sputum smear convert; 13.3 % (1411 of 10,574) of new cases and 9.9 % (216 of 2168) of re-treatment cases. Although not statistically significant in either new or re-treatment cases, between 2007 and 2013, smear non-conversion decreased from 16.4 to 12.7 % (slope = -0.60; 95 % CI: -1.49 to 0.29; p = 0.142) in new cases, and from 11.3 to 10.8 % in re-treatment cases (slope = -0.29; 95 % CI: -1.06 to 0.48; p = 0.376). Male gender, HIV co-infection and a >2+ acid fast bacilli (AFB) smear grading at the start of TB treatment were independent risk factors for non-conversion (p < 0.001). Age was a risk factor for non-conversion in new cases, but not for re-treatment cases. Non-conversion was also associated with unsuccessful treatment outcomes (p < 0.01), including treatment default and treatment failure. CONCLUSIONS: Smear-positive PTB cases, especially men and those with identified risk factors for non-conversion, should be closely monitored throughout their treatment period. The South African TB control program should invest in patient adherence counselling and education to mitigate TB non-conversion risk factors, and to improve conversion and TB cure rates.

Decreased Ebola Transmission after Rapid Response to Outbreaks in Remote Areas, Liberia, 2014.

We measured the reproduction number before and after interventions were implemented to reduce Ebola transmission in 9 outbreaks in Liberia during 2014. We evaluated risk factors for secondary cases and the association between patient admission to an Ebola treatment unit (ETU) and survival. The reproduction number declined 94% from 1.7 (95% CI 1.1-2.6) to 0.1 (95% CI 0.02-0.6) after interventions began. The risk for secondary infections was 90% lower for patients admitted to an ETU (risk ratio 0.1, 95% CI 0.04-0.3) than for those who died in the community. The case-fatality rate was 68% (95% CI 60-74), and ETU admission was associated with a 50% reduction in death (hazard ratio 0.5, 95% CI 0.4-0.8). Isolation and treatment of Ebola patients had the dual benefit of interrupting community transmission and improving survival.

Retention and risk factors for attrition among adults in antiretroviral treatment programmes in Tanzania, Uganda and Zambia.

OBJECTIVES: We assessed retention and predictors of attrition (recorded death or loss to follow-up) in antiretroviral treatment (ART) clinics in Tanzania, Uganda and Zambia. METHODS: We conducted a retrospective cohort study among adults (≥18 years) starting ART during 2003-2010. We purposefully selected six health facilities per country and randomly selected 250 patients from each facility. Patients who visited clinics at least once during the 90 days before data abstraction were defined as retained. Data on individual and programme level risk factors for attrition were obtained through chart review and clinic manager interviews. Kaplan-Meier curves for retention across sites were created. Predictors of attrition were assessed using a multivariable Cox-proportional hazards model, adjusted for site-level clustering. RESULTS: From 17 facilities, 4147 patients were included. Retention ranged from 52.0% to 96.2% at 1 year to 25.8%-90.4% at 4 years. Multivariable analysis of ART initiation characteristics found the following independent risk factors for attrition: younger age [adjusted hazard ratio (aHR) and 95% confidence interval (95%CI) = 1.30 (1.14-1.47)], WHO stage 4 ([aHR (95% CI): 1.56 (1.29-1.88)], >10% bodyweight loss [aHR (95%CI) = 1.17 (1.00-1.38)], poor functional status [ambulatory aHR (95%CI) = 1.29 (1.09-1.54); bedridden aHR1.54 (1.15-2.07)], and increasing years of clinic operation prior to ART initiation in government facilities [aHR (95%CI) = 1.17 (1.10-1.23)]. Patients with higher CD4 cell count were less likely to experience attrition [aHR (95%CI) = 0.88 (0.78-1.00)] for every log (tenfold) increase. Sites offering community ART dispensing [aHR (95%CI) = 0.55 (0.30-1.01) for women; 0.40 (0.21-0.75) for men] had significantly less attrition. CONCLUSIONS: Patient retention to an individual programme worsened over time especially among males, younger persons and those with poor clinical indicators. Community ART drug dispensing programmes could improve retention.

Knowledge, Attitudes, Practices, and Acceptability of Medical Male Circumcision among Males in Traditionally Circumcising Rural Communities of Alfred Nzo District, Eastern Cape, South Africa.

Male circumcision (MC) reduces HIV transmission risk by up to 60% in heterosexual men. However, uptake of medical male circumcision (MMC) is low in traditionally circumcising communities of South Africa. We assessed knowledge, attitudes, and practices to identify factors predicting acceptability of MMC among males in the Alfred Nzo District. A cross-sectional study was conducted among males aged 15-49 years in this district. Logistic regression was used to identify factors predicting acceptability of MMC. We interviewed 343 males who had a median age of 19 years (interquartile range (IQR): 16-25 years). Of these, 77% (95% confidence interval (CI): 72-82) were circumcised: 77% (95% CI: 71-82) were circumcised in a traditional setting and 21% (95% CI: 16-26) in a medical setting. The median score of knowledge about the benefits of MMC was 62.5% (IQR: 37.5-75.0), with 59% (95% CI: 53-64) demonstrating a positive attitude towards MMC and 68% (95% CI: 63-73) accepting involvement of health workers in MC. Excellent knowledge (adjusted odds ratio (aOR): 3.07, 95% CI: 0.99-9.58, p = 0.053), awareness (aOR: 3.26, 95% CI: 1.08-9.86, p = 0.037), and positive attitude towards MMC (aOR: 2.35, 95% CI: 1.30-4.25, p = 0.005) were associated with acceptability of MMC. Participants demonstrated good knowledge and acceptance of the MMC programme. Knowledge, attitude, and awareness were significant predictors of MMC acceptability.

Impact of Kenya's Frontline Epidemiology Training Program on Outbreak Detection and Surveillance Reporting: A Geographical Assessment, 2014-2017.

Rapid detection and response to infectious disease outbreaks requires a robust surveillance system with a sufficient number of trained public health workforce personnel. The Frontline Field Epidemiology Training Program (Frontline) is a focused 3-month program targeting local ministries of health to strengthen local disease surveillance and reporting capacities. Limited literature exists on the impact of Frontline graduates on disease surveillance completeness and timeliness reporting. Using routinely collected Ministry of Health data, we mapped the distribution of graduates between 2014 and 2017 across 47 Kenyan counties. Completeness was defined as the proportion of complete reports received from health facilities in a county compared with the total number of health facilities in that county. Timeliness was defined as the proportion of health facilities submitting surveillance reports on time to the county. Using a panel analysis and controlling for county-fixed effects, we evaluated the relationship between the number of Frontline graduates and priority disease reporting of measles. We found that Frontline training was correlated with improved completeness and timeliness of weekly reporting for priority diseases. The number of Frontline graduates increased by 700%, from 57 graduates in 2014 to 456 graduates in 2017. The annual average rates of reporting completeness increased from 0.8% in 2014 to 55.1% in 2017. The annual average timeliness reporting rates increased from 0.1% in 2014 to 40.5% in 2017. These findings demonstrate how global health security implementation progress in workforce development may influence surveillance and disease reporting.

One Field Epidemiologist per 200,000 Population: Lessons Learned from Implementing a Global Public Health Workforce Target.

The World Health Organization monitoring and evaluation framework for the International Health Regulations (IHR, 2005) describes the targets for the Joint External Evaluation (JEE) indicators. For workforce development, the JEE defines the optimal target for attaining and complying with the IHR (2005) as 1 trained field epidemiologist (or equivalent) per 200,000 population. We explain the derivation and use of the current field epidemiology workforce development target and identify the limitations and lessons learned in applying it to various countries' public health systems. This article also proposes a way forward for improvements and implementation of this workforce development target.

An economic evaluation of the school-based "power breathing" asthma program.

This study evaluated the cost effectiveness of the "Power Breathing" program for asthma among middle and high school students. Few systematic evaluations of school based interventions--let alone cost-effectiveness programs--have been identified in the literature. Power Breathing was developed by the Asthma and Allergy Foundation of America and is currently available for implementation by school districts. For the overall evaluation, 8 junior high schools and 2 high schools were selected and matched based on grade range, enrollment, income and race/ethnicity. Schools were randomly assigned to the intervention or control group. Surveys were administered at baseline, immediately post-intervention and 3 months' post-intervention. Children in the intervention arm had a significant decrease in the number of days they experienced an asthma attack or had trouble breathing during a 2-week period of 0.18 days per 2 weeks. In contrast, subjects in the control group had an increase in the in the number of days experiencing an asthma attack or having trouble breathing during a 2-week period of 0.102, from 0.696 to 0.793. The program cost approximately $3.9 per asthma attack-free day gained, on par with pharmaceutical interventions, suggesting that Power Breathing may be a cost effective asthma intervention. The results of this study suggest that school-based interventions aimed at asthma, properly implemented and administrated, are an appropriate use of societal resources.

Evaluating the electronic tuberculosis register surveillance system in Eden District, Western Cape, South Africa, 2015.

BACKGROUND: Tuberculosis (TB) surveillance data are crucial to the effectiveness of National TB Control Programs. In South Africa, few surveillance system evaluations have been undertaken to provide a rigorous assessment of the platform from which the national and district health systems draws data to inform programs and policies. OBJECTIVE: Evaluate the attributes of Eden District's TB surveillance system, Western Cape Province, South Africa. METHODS: Data quality, sensitivity and positive predictive value were assessed using secondary data from 40,033 TB cases entered in Eden District's ETR.Net from 2007 to 2013, and 79 purposively selected TB Blue Cards (TBCs), a medical patient file and source document for data entered into ETR.Net. Simplicity, flexibility, acceptability, stability and usefulness of the ETR.Net were assessed qualitatively through interviews with TB nurses, information health officers, sub-district and district coordinators involved in the TB surveillance. RESULTS: TB surveillance system stakeholders report that Eden District's ETR.Net system was simple, acceptable, flexible and stable, and achieves its objective of informing TB control program, policies and activities. Data were less complete in the ETR.Net (66-100%) than in the TBCs (76-100%), and concordant for most variables except pre-treatment smear results, antiretroviral therapy (ART) and treatment outcome. The sensitivity of recorded variables in ETR.Net was 98% for gender, 97% for patient category, 93% for ART, 92% for treatment outcome and 90% for pre-treatment smear grading. CONCLUSIONS: Our results reveal that the system provides useful information to guide TB control program activities in Eden District. However, urgent attention is needed to address gaps in clinical recording on the TBC and data capturing into the ETR.Net system. We recommend continuous training and support of TB personnel involved with TB care, management and surveillance on TB data recording into the TBCs and ETR.Net as well as the implementation of a well-structured quality control and assurance system.

Decline in syphilis seroprevalence among females of reproductive age in Northern Cape Province, South Africa, 2003-2012: utility of laboratory-based information.

Strengthening current surveillance systems for syphilis is important to track and monitor disease burden. We used routinely collected laboratory information to generate surveillance estimates for syphilis trends among women of reproductive age (12-49 years) in the Northern Cape Province, a high syphilis burden region (2003 [8.6%] to 2011 [3.8%]) in South Africa. We extracted records meeting inclusion criteria from the National Health Laboratory Service electronic database for the period 2003-2012. A total of 286,024 women were included in the analysis. Syphilis seropositivity decreased between 2003 (5.7%) and 2012 (1.8%); p trend = 0.001, which was largely consistent with findings reported in the annual national syphilis and HIV survey from 2003 (8.6%) to 2011 (3.8%). Annually for the period from 2003 to 2012 there was an approximate 14% reduction in the prevalence ratio of syphilis seroprevalence (PR = 0.86, 95% CI = 0.85-0.87, p < 0.001). Three of five districts had significant decreases in syphilis seropositivity over this period. There were also declines in prevalence ratios for syphilis seropositivity for the various age groups for the period. This study shows that the national laboratory database in South Africa can be used as a complimentary surveillance tool to describe and understand trends in syphilis seroprevalence in South Africa.

Does a multifaceted environmental intervention alter the impact of asthma on inner-city children?

OBJECTIVE: To evaluate the impact of a multifaceted environmental and educational intervention on the indoor environment and health in 5-12-year-old children with asthma living in urban environments. DESIGN: Changes in indoor allergen levels and asthma severity measurements were compared between children who were randomized to intervention and delayed intervention groups in a 14-month prospective field trial. Intervention group households received dust mite covers, a professional house cleaning, and had roach bait and trays placed in their houses. RESULTS: Of 981 eligible children, 410 (42%) were enrolled; 161 (40%) completed baseline activities and were randomized: 84 to intervention and 77 to delayed intervention groups. At the study's end, dust mite levels were 163% higher than at baseline for the delayed intervention group. Overall asthma severity scores did not change. However, the median functional severity score (FSS) component of the severity score improved more in the intervention group (33% vs. 20%) than in the delayed intervention group. At the study's end, the median FSSs for the intervention group improved 25% compared with the delayed intervention group, (p<0.01). Differences between groups for medication use, emergency department (ED) visits or hospitalization were not significant. CONCLUSIONS: Despite low retention, the intervention resulted in decreased dust mite allergen levels and increased FSSs among the intervention group. The interventions probably contributed to the improvements, especially among the more severely affected children. This study highlights the complexities of designing and assessing the outcomes from a multifaceted asthma intervention.

Reasons for Missing Antiretroviral Therapy: Results from a Multi-Country Study in Tanzania, Uganda, and Zambia.

OBJECTIVES: To identify the reasons patients miss taking their antiretroviral therapy (ART) and the proportion who miss their ART because of symptoms; and to explore the association between symptoms and incomplete adherence. METHODS: Secondary analysis of data collected during a cross-sectional study that examined ART adherence among adults from 18 purposefully selected sites in Tanzania, Uganda, and Zambia. We interviewed 250 systematically selected patients per facility (≥ 18 years) on reasons for missing ART and symptoms they had experienced (using the HIV Symptom Index). We abstracted clinical data from the patients' medical, pharmacy, and laboratory records. Incomplete adherence was defined as having missed ART for at least 48 consecutive hours during the past 3 months. RESULTS: Twenty-nine percent of participants reported at least one reason for having ever missed ART (1278/4425). The most frequent reason was simply forgetting (681/1278 or 53%), followed by ART-related hunger or not having enough food (30%), and symptoms (12%). The median number of symptoms reported by participants was 4 (IQR: 2-7). Every additional symptom increased the odds of incomplete adherence by 12% (OR: 1.1, 95% CI: 1.1-1.2). Female participants and participants initiated on a regimen containing stavudine were more likely to report greater numbers of symptoms. CONCLUSIONS: Symptoms were a common reason for missing ART, together with simply forgetting and food insecurity. A combination of ART regimens with fewer side effects, use of mobile phone text message reminders, and integration of food supplementation and livelihood programmes into HIV programmes, have the potential to decrease missed ART and hence to improve adherence and the outcomes of ART programmes.

Molecular characterisation and epidemiological investigation of an outbreak of blaOXA-181 carbapenemase-producing isolates of Klebsiella pneumoniae in South Africa.

BACKGROUND: Klebsiella pneumoniae is an opportunistic pathogen often associated with nosocomial infections. A suspected outbreak of K. pneumoniae isolates, exhibiting reduced susceptibility to carbapenem antibiotics, was detected during the month of May 2012 among patients admitted to a haematology unit of a tertiary academic hospital in Cape Town, South Africa (SA). OBJECTIVES: An investigation was done to determine possible epidemiological links between the case patients and to describe the mechanisms of carbapenem resistance of these bacterial isolates. METHODS: Relevant demographic, clinical and laboratory information was extracted from hospital records and an observational review of infection prevention and control practices in the affected unit was performed. Antimicrobial susceptibility testing including phenotypic testing and genotypic detection of the most commonly described carbapenemase genes was done. The phylogenetic relationship of all isolates containing the blaOXA-181 carbapenemase gene was determined by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing. RESULTS: Polymerase chain reaction analysis identified a total of seven blaOXA-181-positive, carbapenem-resistant K. pneumoniae isolates obtained from seven patients, all from a single unit. These isolates were indistinguishable using PFGE analysis and belonged to sequence type ST-14. No other carbapenemase enzymes were detected. CONCLUSION: This is the first documented laboratory-confirmed outbreak of OXA-181-producing K. pneumoniae in SA, and highlights the importance of enforcing strict adherence to infection control procedures and the need for ongoing surveillance of antibiotic-resistant pathogens in local hospitals.

Asthma and influenza vaccination: findings from the 1999-2001 National Health Interview Surveys.

STUDY OBJECTIVES: People with asthma are at high risk for complications from influenza; therefore, the Centers for Disease Control and Prevention recommends an annual influenza vaccination for people with asthma. Because little is known about such vaccination rates among adults, especially those aged 18 to 49 years and 50 to 64 years, we sought to estimate influenza vaccination rates among US adults. DESIGN: Cross-sectional analyses of the 1999 to 2001 National Health Interview Surveys. SETTING: US population. PARTICIPANTS: Representative samples of US adults aged > or =18 years. MEASUREMENTS AND RESULTS: Asthma status and receipt of influenza vaccination during the past 12 months were self-reported. We found that 35.1% (95% confidence interval [CI], 33.0 to 37.0%), 36.7% (95% CI, 34.7 to 38.6%), and 33.3% (95% CI, 31.6 to 35.0%) of participants with asthma reported having had an influenza vaccination in 1999 (n = 2,620), 2000 (n = 3,007), and 2001 (n = 3,582), respectively. Among participants aged 18 to 49 years, the vaccination rates were 20.9% (SE 1.2%), 22.7% (SE 1.2%), and 21.1% (SE 1.0%), respectively. Among participants aged 50 to 64 years, the vaccination rates were 46.2% (SE 2.6%), 47.8% (SE 2.3%), and 42.3% (SE 2.1%), respectively. Vaccination rates increased strongly with age and with education in each year. Associations with sex or with race or ethnicity were inconsistent during the 3 years. CONCLUSIONS: The suboptimal vaccination rates among people with asthma aged 18 to 64 years suggest the need to increase influenza vaccination rates in this age group.

Retention factors for participants of an inner-city community-based asthma intervention study.

Participant retention is a significant challenge for asthma field trials examining the effectiveness of prevention strategies in inner-city communities. Here, the authors evaluate factors associated with participant retention in an inner-city, pediatric, asthma intervention trial in Atlanta, Georgia, during 1998-2000. Demographic, clinical, residential, personnel, and logistical variables were analyzed by chi-square and Wilcoxon rank sum nonparametric tests to compare children who remained in the asthma study with those who were dropped. Of the 489 participants, 486 (99%) were African-American, 467 (96%) were non-Hispanic, 281 (57%) were male, and 142 (29%) remained in the study. Of the 347 dropouts, 149 (43%) were dropped because of missing study visits. Retention rates were significantly higher (P<.05) for participants enrolled in the second year of the study (2nd yr=43%, 1st yr=19%), for those who lived longer at the same residence (> or = 3 yrs=36%, 2-3 yrs=26%, 1-<2 yr=22%), and for those enrolled during a face-to-face follow-up home visit, rather than at the emergency department (ED) (follow-up=38%, ED=27%). Neither sex nor enrollment season were associated with retention. These findings underscore the importance of performing a comprehensive pilot study and considering a home residency period for participant enrollment eligibility, along with alternative study methods that take into account the challenges of retaining participants.