Applying the zero-inflated Poisson model with random effects to detect abnormal rises in school absenteeism indicating infectious diseases outbreak.

Records of absenteeism from primary schools are valuable data for infectious diseases surveillance. However, the analysis of the absenteeism is complicated by the data features of clustering at zero, non-independence and overdispersion. This study aimed to generate an appropriate model to handle the absenteeism data collected in a European Commission granted project for infectious disease surveillance in rural China and to evaluate the validity and timeliness of the resulting model for early warnings of infectious disease outbreak. Four steps were taken: (1) building a 'well-fitting' model by the zero-inflated Poisson model with random effects (ZIP-RE) using the absenteeism data from the first implementation year; (2) applying the resulting model to predict the 'expected' number of absenteeism events in the second implementation year; (3) computing the differences between the observations and the expected values (O-E values) to generate an alternative series of data; (4) evaluating the early warning validity and timeliness of the observational data and model-based O-E values via the EARS-3C algorithms with regard to the detection of real cluster events. The results indicate that ZIP-RE and its corresponding O-E values could improve the detection of aberrations, reduce the false-positive signals and are applicable to the zero-inflated data.

Using daily syndrome-specific absence data for early detection of school outbreaks: a pilot study in rural China.

OBJECTIVES: This paper describes and preliminarily evaluates the usefulness of the daily syndrome-specific absenteeism surveillance system (DSSASS) as an early warning system of school outbreaks in rural China. STUDY DESIGN: We conducted an experimental study in rural areas of Hubei Province from September 19, 2011 to December 31, 2011. METHODS: Nine public elementary schools from two counties were selected as pilot sentinel schools. Daily monitoring data of the absent date and reason, sex, age and class of each absent student was collected and entered into a web database. Reported data were checked daily and field investigation was carried out when there was abnormal absentee aggregation. Descriptive analysis and preliminary evaluation were then conducted after the pilot study. RESULTS: The findings showed that the total average of daily absenteeism rate was 3%, and the absenteeism rate differed by county, school level and grade level. The daily absenteeism rate in illness absentees was highest (2.74%), followed by business absentees (0.13%) and injury absentees (0.09%). The total timeliness report rate was 64.84% and the total incident report rate was 29.22%. One varicella outbreak and one influenza B outbreak were identified, but neither of them was detected by China Information System for Diseases Control and Prevention (CISDCP). The study shows syndrome-specific absenteeism data would be useful for early detection of unusual public health events or outbreaks in school. However, more efforts are needed to enhance the quality of surveillance data, and longer follow-up and more analysis are required to evaluate the system comprehensively. Our study might provide useful experience and evidence for other developing regions or counties establishing similar systems.

Community perceptions of tuberculosis: A qualitative exploration from a gender perspective.

OBJECTIVE: To explore community laypersons' perspective on tuberculosis (TB)-related illness experiences, meanings, behaviours and impact with reference to gender. STUDY DESIGN: Qualitative, conducted in rural Bangladesh. METHODS: Eleven focus group discussions (FGDs) were conducted (six female and five male) in five subdistricts where the non-governmental organization BRAC operates. On average, seven purposively chosen poor, illiterate, non-TB patients participated in each FGD. Discussions were audiotaped, translated verbatim into English and analysed using MAXQDA software for qualitative data analysis, used it to assign codes to text segments to identify themes from participants' narratives. RESULTS: TB was recognized as a deadly disease that could affect anyone. The discussants were fairly aware of the psychological, financial and social impacts of TB. Women faced with adverse consequences more often than men, such as trouble in ongoing and prospective marital affairs. Coughing up sputum in public by women is culturally frowned upon, resulting in enormous suffering. Women tended to describe the clinical features more vaguely than men, and often specified fewer characteristic symptoms such as blood in sputum. CONCLUSIONS: The gender differences in the health and socio-economic impact of TB included perceived causality, curability, stigma, family and community support, fear of disclosure, and use of self-help or home remedies. Interactive health education covering various consequences of TB could be indispensable to changing negative beliefs.

PPM: 'public-private' or 'private-public' mix? The case of Ujjain District, India.

The World Health Organization and the Revised National TB Control Programme (RNTCP) in India have advocated public-private mix as essential for tuberculosis (TB) control. We conducted a cross-sectional sample survey of private providers (with various qualifications) in Ujjain District, India, to study willingness and motivation to collaborate. Most providers were aware of the RNTCP and had referred patients there. All were willing to collaborate, although the areas for collaboration varied between urban and rural providers. General altruism and an opportunity to collaborate with the government were the main motivations. None of the providers had ever been contacted by the RNTCP. Enthusiasm in the private sector has not been effectively exploited by the RNTCP.

Female-male differences at various clinical steps of tuberculosis management in rural Bangladesh.

A registry data-based study of 3,600 patients systematically drawn from out-patient clinic, laboratory and tuberculosis (TB) treatment registers (1200 from each) examined female-male differences at various clinical steps of TB management and compared selective indicators with published results. Female-to-male ratios (FMR) declined at the following clinical steps: respiratory patients seeking out-patient care (0.81), TB suspects submitting sputum for testing (0.52) and smear-positive test results (0.38), but the decline ceased at treatment initiation (0.41). Compared to 1997, the FMR in 2000 had decreased for out-patient clinics and sputum submission for testing, but had increased for smear-positive test results and treatment initiation. More female than male patients who underwent treatment achieved cure (93% vs. 89%). Lower female representation at the different clinical steps of TB management persists.

Towards the elimination of tuberculosis in a developing country: 25 years of tuberculosis control in Oman.

OBJECTIVE: To analyse trends of tuberculosis (TB) in Oman (1981-2005) in relation to the socio-economic development of the country. METHODS: Data were used from the National Tuberculosis Control Programme (NTP). Information on TB cases' age, sex and type were obtained from the national book (1981-1991) and the computer database (1992-2005). RESULTS: TB notification rates among Omani nationals declined by more than 85% from 1981 to 1995. During the period 1981-1993, the TB notification rate declined by around 15% per year, compared to only 3.6% per year in subsequent years. Males and the age group > or = 50 years have higher rates than females and younger age groups, respectively. Non-nationals contributed 21% of all TB cases notified and 40% of all smear-positive cases. Of cases among nationals notified between 2004 and 2005, 95% had a family income lower than the national average. CONCLUSION: Although TB notification in Oman has declined by more than 85% over the last 25 years, the decline has slowed down over the last 10 years, requiring a detailed analysis of existing TB control measures and implementation of additional measures for TB elimination.

Health care seeking among individuals with cough and tuberculosis: a population-based study from rural India.

SETTING: Ujjain district, Madhya Pradesh, India. OBJECTIVE: To describe and compare health care seeking among men and women with cough of >3 weeks, with special focus on the utilisation of private and public health care. DESIGN: A population-based cross-sectional survey including 45 719 individuals aged > or = 15 years. RESULTS: The prevalence of cough was respectively 2.8% and 1.2% among men and women. The majority of men and women reported seeking health care for their symptoms (69% vs. 71%), but only 23% visited a public provider at some point during their illness. A similar health care seeking pattern was found for patients diagnosed with tuberculosis (TB) in our survey. No significant differences in health care seeking were found between men and women. Only 13% of those seeking care reported having had a sputum smear examination since the onset of cough. Factors associated with sputum examination were history of TB, haemoptysis and visiting a public provider. CONCLUSION: The low utilisation of public health care services and the few sputum examinations reported in this rural Indian setting illustrate the need for improved diagnostic practices as well as involvement of private providers in TB control activities.

Diagnostic delays in access to tuberculosis care in counties with or without the National Tuberculosis Control Programme in rural China.

SETTING: A county covered by the National Tuberculosis Control Programme (NTP) (Jianhu) and a nonprogramme county (Funing) in Jiangsu Province, China. OBJECTIVE: To compare diagnostic delays among tuberculosis (TB) patients between counties with and without the NTP, and to study the impact of demographic, socioeconomic and policy factors on the delays. DESIGN: A cohort study of 493 newly diagnosed TB patients registered in the study sites during 2002 was conducted using a structured questionnaire interview. RESULT: The median total diagnostic delay was longer in Jianhu County, 31 (14-68) days, compared to Funing County, 19 (12-34) days, with a shorter patient's delay (10 vs. 16 days, P < 0.05) but a longer doctor's delay (6 vs. 0 days, P < 0.01) in Jianhu than in Funing. Smear-positive TB accounted for 86% of patients in Jianhu, compared to 37% in Funing. Less educated and uninsured patients had longer patient's or doctor's delays in Jianhu, while in Funing poor patients and farmers had both longer patient's and doctor's delays. CONCLUSION: The subsidised NTP leads to a shorter patient's delay, but a longer doctor's delay, with a substantially higher proportion of smear-positive TB diagnosis. Education, medical insurance, poverty and the system of TB control can influence patients' access to TB care.

Lay health worker intervention with choice of DOT superior to standard TB care for farm dwellers in South Africa: a cluster randomised control trial.

SETTING: Farms in the Boland health district, Western Cape Province, South Africa. OBJECTIVE: To evaluate the effect of lay health workers (LHWs) on tuberculosis (TB) control among permanent farm workers and farm dwellers in an area with particularly high TB prevalence. DESIGN: Pragmatic, unblinded cluster randomised control trial. METHODS: This trial measured successful treatment completion rates among new smear-positive (NSP) adult TB patients on 106 intervention farms, and compared them with outcomes in patients on 105 control farms. Farms were the unit of randomisation, and analysis was by intention to treat. RESULTS: A total of 164 adult TB patients were recruited into the study, 89 of whom were NSP. The successful treatment completion rate in NSP adult TB patients was 18.7% higher (P = 0.042, 95%CI 0.9-36.4) on farms in the intervention group than on farms in the control group. Case finding for adult NSP TB cases was 8% higher (P = 0.2671) on farms in the intervention group compared to the control group. CONCLUSION: Trained LHWs were able to improve the successful TB treatment rate among adult NSP TB patients in a well-established health service, despite reduction of services.

Community- and hospital-acquired pneumonia associated with Chlamydia TWAR infection demonstrated serologically.

Serum specimens from 198 patients with pneumonia hospitalized in Seattle between October 1980 and April 1981 were retrospectively tested for antibody against a recently described Chlamydia organism called TWAR. They had been previously tested for antibody for some viruses and Mycoplasma. Twenty (10%) had serologic evidence of recent TWAR infection. The hospital records of the patients with acute TWAR antibody and an equal number of matched controls were examined for clinical characteristics, laboratory tests, treatment, and course during the hospital stay. It was not possible clinically or roentgenographically to distinguish pneumonia associated with TWAR antibody from pneumonia in the controls. Nine of 20 patients with TWAR antibody acquired pneumonia during their hospital stay. The mode of transmission in the hospital was not determined. All the patients with hospital-acquired pneumonia had been intubated, and all had had some surgical procedure. Ten of 20 control patients had onset of their pneumonia in the hospital. Fifteen (11%) of 142 of the patients with pneumonia had evidence of influenza A virus infection. The clinical characteristics of their pneumonias were similar to those of the patients with acute TWAR antibody.

Drug use and the role of patients and prescribers.

In order to move towards rational drug use in any national or local setting the methods of inquiry have to be expanded. Both the public and private sector have to be addressed. In the latter the pharmacists might be studied using a tracer, fictitious client. One important factor influencing prescribing, drug information, has rarely been assessed scientifically. Experimental studies using group randomization are, however feasible even in developing countries. The individual human being must be in the focus of drug studies and health care and health in the foreground. The combination of qualitative and quantitative methods will assist us to achieve rational drug use that is culturally acceptable, economically feasible and pharmacologically sound.

PIP: In the effort to improve rational drug use in local or national settings, especially in developing countries, the behavior of prescribers and users is the subject of the least research. The effectiveness of drugs depends on a complex set of factors involved in the situation of prescription and acquisition. One aspect that needs examination is the information given to prescribers by drug advertisers and detailers, a deficiency being addressed by an international network of prescribers. In many countries, the largest outlet for drugs is the private sector pharmacies, where drugs are often dispensed without prescription. A simple inexpensive way of researching prescription behavior is to use fictitious tracers to follow case management of given conditions, such as infant diarrhea. There are many factors involved in prescribing; the process must be studied with an epidemiologic approach, i.e., by description, analysis, intervention and evaluation. Standard treatment schedules, essential drugs lists, targeted intervention with treatment guidelines should be audited by local therapeutic committees. Drug information should also be scientifically evaluated by the same analytical principles. The experimental method of group randomization is suggested as a feasible choice for developing countries. In this technique groups of physicians are observed or interviewed, and quantitative outcome data are collected. Behavior of individual users is best studied by combining anthropological and biomedical approaches, from the case-study perspective. An example of a problem amenable to this approach is the possible use of shorter courses of antibiotic treatment to lessen the risk of development of resistant organisms.

Do women with tuberculosis have a lower likelihood of getting diagnosed? Prevalence and case detection of sputum smear positive pulmonary TB, a population-based study from Vietnam.

OBJECTIVE: The aim was to estimate the gender-specific prevalence of tuberculosis (TB) through screening. A further aim was to calculate case detection within the Vietnamese National TB program. STUDY DESIGN AND SETTING: A population-based survey of 35,832 adults was performed within an existing sociodemographic longitudinal study in Bavi district, northern Vietnam. Cases were identified by a screening question about prolonged cough and further diagnosed with sputum examination and a chest X-ray. RESULTS: The estimated prevalence of pulmonary TB among men was 90/100,000 (95% CI 45-135/100,000) and among women 110/100,000 (95% CI 63-157/100,000). Case detection in the district was estimated to 39% (95% CI 20-76%) among men and 12% (95% CI 6-26%) among women. CONCLUSION: TB prevalence was similar among men and women. Case detection among men and women was significantly lower than the reported national case detection of 80%, and there was a significant underdetection of female cases. These findings warrant actions, and emphasize the need to perform similar studies in different contexts.

Influencing prescribing for urinary tract infection and asthma in primary care in Sweden: a randomized controlled trial of an interactive educational intervention.

Our aim was to evaluate effects on prescribing for urinary tract infection (UTI) and asthma, of an education with messages based on national guidelines, aimed at improving prescribing in primary care in Sweden. The study is part of the European Drug Education Project. A randomized controlled trial, with groups of general practitioners (GPs) allocated to education on UTI (18 groups, 104 GPs) or asthma (18 groups, 100 GPs), the two parallel intervention arms being controls for each other. Feedback was provided on the GP's judgments of simulated cases and prescribing. Prescribing indicators were developed and measured before and after the intervention. Analysis was performed by multi-level technique. Prescribing of first choice UTI drugs increased in the intervention arm from 52% to 70% and remained constant in the control arm (P < 0.001). The proportion of patients receiving an inhaled corticosteroid increased insignificantly in both study arms. The educational model can be used to improve prescribing. Further studies are needed to define when the model is effective.

Improving drug use through continuing education: a randomized controlled trial in Zambia.

The objective of this study was to evaluate the impact of three continuing education seminars (within a period of 4 months) on the quality of patient management and rational drug use. The study was designed as a randomized controlled trial. Prescribers in 16 general health centers were allocated to an intervention (eight health centers) or a control (eight health centers) group. A total of 5,685 patient cards was analyzed for quality of case management and rational drug use. In the intervention health centers the average number of drugs per patient decreased from 2.3 to 1.9 (p = 0.005) and the proportion of patients managed with nonpharmacological treatment increased from 1 to 13.2%. Recorded history taking, examination, and diagnosis improved in the intervention health centers. More drugs were correctly chosen in the intervention health centers compared to control health centers (p = 0.03). The proportion of patients prescribed antibiotics decreased and the proportion of patients adequately managed increased in the intervention health centers. Our conclusion is that continuing education in the form of repeated seminars is effective in influencing prescribers and in promoting rational drug use in primary care.

Effects of "group detailing" on the prescribing of lipid-lowering drugs: a randomized controlled trial in Swedish primary care.

The objective was to study the effect of "academic group detailing" on the prescribing of lipid-lowering drugs in Swedish primary care. A randomized controlled trial was conducted, randomization being by group. Groups of doctors at 134 community health centres were randomly allocated to an intervention and a control group. The 67 intervention health centres were offered four sessions, conducted by a pharmacist, with group information on guidelines for the management of hyperlipidaemia. The number of prescriptions of lipid-lowering drugs per month increased in the intervention health centres and the increase was statistically different from the corresponding change in the control health centres among women in the age group 30-65 years (p = 0.03). The prescription of first-line lipid-lowering drugs increased by 20% in the intervention health centres (p = 0.03). "Academic group detailing" by pharmacists to primary care doctors can be an effective method for influencing prescribing practices.

Experimental evaluation of the effects of drug information on antibiotic prescribing: a study in outpatient care in an area of Sri lanka.

The intervention level of epidemiology is useful for studying effects in health systems research. Due to practical and ethical reasons, it is often difficult to apply experimental methods such as classical randomized clinical trials in the field. However with alternative approaches such as 'randomization by group' some of these problems can be overcome. Drug information has since long been considered as an instrument to influence physicians, however evaluation of its effects is a new field of research. In the present study the impact of drug information on prescribing behaviour was evaluated in an outpatient setting in Sri Lanka. The study included 15 state health institutions (45 prescribers) with a common drug formulary. Groups of prescribers were randomized into two interventions; newsletters and newsletters reinforced by a group seminar, and one control group. The target topic was 'rational prescribing of antibiotics'. Some 18,766 randomly selected outpatient drug prescriptions were studied. Antibiotics (and sulphonamides) were prescribed to 33.2% of the patients. An overall trend towards a decrease in proportion of patients prescribed antibiotics in the two intervention groups was seen, although the difference was not significant (p greater than 0.05) compared to the control group. This is similar to the effect of written information on prescribing in other studies. A mean difference of -7.4% in written, -7.3% in written + seminar and -0.4% in the control group was shown. The general antibiotic prescribing pattern did not change in any of the three groups. Penicillin was the most commonly prescribed antibiotic and tetracycline was only rarely prescribed to children. This experiment indicates the feasibility of drug information intervention studies in developing countries.(ABSTRACT TRUNCATED AT 250 WORDS)

Randomization by group in studying the effect of drug information in primary care.

Drug information is a technology which is rarely evaluated. Practical and ethical considerations limit the use of a classical experimental method (a randomized controlled trial) in studying the effect of drug information in primary care. An alternative approach, randomization by group, is preferable for several reasons: it avoids contamination of the control group; the effect of information can be evaluated in the natural working environment; and the impact of information is increased via diffusion. This article describes the selection of a control group, the Hawthorne effect and 'blindness' in information experiments. Sample size tables and power calculations are presented when randomization by group is used. The study power is influenced by the number of health centres and the variance between them. The number of doctors per health centre plays a less important role, and the number of patients is relatively unimportant. There is also a need to use qualitative methods to prepare information and to understand factors influencing change of behaviour among prescribers.

Protective effect of BCG against tuberculous meningitis and miliary tuberculosis: a meta-analysis.

The protective effect of BCG against tuberculosis (TB) estimated in randomized controlled trials and observational studies ranges from negative to close to a 100%. One of the many explanations offered for this is that different immunological mechanisms may be associated with protective effect against different forms and sites of disease. In this investigation, we recalculated vaccine protective effect separately for pulmonary disease and for meningeal/miliary disease in randomized controlled trials and case-control studies, tested for heterogeneity in site-specific estimates of protective effect and calculated a summary measure when appropriate. We found protective effect against pulmonary disease to be heterogeneous to a statistically significant degree, and thus we did not calculate a summary measure of protection. Protective effect against meningeal and miliary TB was higher than against pulmonary disease and, except for a single study with two cases only, appeared to be homogenous. Summary BCG protective effect against miliary or meningeal TB in randomized controlled trials was 86% (95% confidence interval [CI] 65, 95) and in case-control studies 75% (95% CI: 61, 84). The fact that protective effect appeared to be homogeneous against meningitis and miliary TB but not against pulmonary disease may result from the fact that patients with meningitis are on average younger and thus less likely to have been exposed to atypical bacteria; to a waning of the protective effect of BCG; or from the diversity of mechanisms of pathogenesis of pulmonary disease, which can originate from reinfection, reactivation or primary progression.

Should the 'bleach microscopy method' be recommended for improved case detection of tuberculosis? Literature review and key person analysis.

SETTING: It has been proposed that the sensitivity of direct sputum smear microscopy can be improved if sputum is liquefied with sodium hypochlorite (NaOCl or household bleach), and concentrated by centrifugation before acid-fast staining. OBJECTIVE: To summarise the results of the studies of the bleach method for improved sensitivity of sputum microscopy and to describe the opinions and knowledge of key persons in National Tuberculosis Control Programmes (NTPs) about this method. DESIGN: We searched Medline, EMBASE and Web of Science for studies comparing the bleach method to direct sputum smear microscopy in low- or middle-income countries. Each study was assessed regarding methodology and field applicability. We also sent out questionnaires concerning the bleach method to key persons in NTPs in 85 countries. RESULTS: In 15 of the 19 studies identified there was a statistically significant improvement in the proportion of positive tests or sensitivity ranging from 7-253%. The majority (73%) of the key persons had heard of the bleach method. Forty-four per cent thought it could improve case detection in their countries, while 49% did not know; 93% of them would promote the bleach method; the most common reasons for doing so would be recommendations from the WHO or the IUATLD, or favourable studies performed in their own country. The bleach method was used routinely in only three countries. CONCLUSION: There is enough evidence to recommend the evaluation and introduction of the bleach method in most settings where mycobacterial culture is not performed routinely.

Attitudes to compliance with tuberculosis treatment among women and men in Vietnam.

SETTING: A study carried out in 1996 in four districts representing south and north as well as urban and rural areas of Vietnam. OBJECTIVE: To explore gender differences in knowledge, beliefs and attitudes towards tuberculosis and its treatment, and how these factors influence patients' compliance with treatment. DESIGN: Sixteen focus group discussions were performed by a multi-disciplinary research team from Vietnam and Sweden. Analysis was performed using modified Grounded Theory technique, specifically evaluating gender differences. RESULTS: Women were believed to be more compliant than men. Insufficient knowledge and individual cost during treatment were reported as main obstacles to compliance among men (poor patient compliance), while sensitivity to interaction with health staff and stigma in society (poor health staff and system compliance) were reported as the main obstacles among women. CONCLUSIONS: It is time to adopt a more comprehensive and gender-sensitive approach to compliance, which incorporates patient compliance, doctor compliance and system compliance, in order to fully support individual patients in their efforts to comply with treatment.