principles of epidemiologyin public health practice_part6 pptx

Public Health Surveillance Page 5-58 study; with notifications, the observation period can be extended until sufficient numbers of cases are collected. Disadvantages • Might not provide a representative picture of the incidence or prevalence unless care is taken in selecting reporting sites and ensuring complete reporting. • Data that can be collected are limited by the skill, time, and willingness of the data collectors, who usually have other responsibilities. • Quality control might be a major problem in data collection. • The quality of data might vary among collection sites. • As a result, notifications usually provide a substandard estimate of the true incidence and prevalence. An alternative to notification might be to enroll interested and appropriate health-care providers and clinics in a sentinel system to gather case numbers of asthma. Exercise 5.3 Factors that influence the choice of one source of data or one dataset over another include severity of illness (e.g., hospitalization and mortality); need for laboratory confirmation of diagnosis; rarity of the condition; specialization, if any, of the health-care providers who commonly examine patients with the condition under surveillance; quality, reliability, or availability of relevant data; and timeliness of the data in terms of need for response. Listeriosis: A wide spectrum of nonspecific clinical illness and a low case fatality rate exists (except among newborns and immunocompromised persons). Therefore, surveillance should be based on morbidity rather than mortality data; diagnoses should be confirmed in the laboratory. Possible sources of surveillance data include laboratory reports, hospital discharge data (although patients with listeriosis are often not hospitalized), or adding listeriosis to the notifiable disease list. Spinal cord injury: This is a severe health event with substantial mortality; almost all persons who sustain a spinal cord injury are brought to a hospital. Therefore, surveillance would most logically be based on hospital records and mortality data (e.g., death certificates or medical examiner data). Special efforts might be directed to obtaining data from regional trauma centers. Using data from emergency medical services and rehabilitation centers might also be explored. Lung cancer among nonsmokers: Similar to spinal cord injury, lung cancer is a severe health event with high morbidity and mortality. Unfortunately, hospital discharge records and vital records do not routinely provide smoking information. For this condition, cancer registries might provide the best opportunity for surveillance, if smoking information is routinely collected. Alternatively, surveillance might be established by using interested internists, oncologists, and other health-care providers likely to interact with lung cancer patients. Exercise 5.4 Possible explanations for the sudden increase include those listed in the following. Each possibility should be investigated before deciding that the increase is a true increase in incidence. This is trial version www.adultpdf.com Public Health Surveillance Page 5-59 1. Change in surveillance system or policy of reporting. 2. Change in case definition. 3. Improved or incorrect diagnosis. • New laboratory test. • Increased physician awareness of the need to test for tuberculosis, new physician in town, and so forth. • Increase in publicity or public awareness that might have prompted persons or parents to seek medical attention for compatible illness. • New population subgroup (e.g., refugees) in state A who have previous recent vaccination against tuberculosis using the bacille de Calmette-Guérin (BCG) vaccine. • New or untrained staff conducting testing for tuberculosis and incorrect interpretation of skin reaction to tuberculin. 4. Increase in reporting (i.e., improved awareness of requirement to report). 5. Batch reporting (unlikely in this scenario). 6. True increase in incidence. Exercise 5.5 No right answer exists, but one set of tables for health department staff might be as follows: Table 1. Number of reported cases of each notifiable disease this week for each county in the state. Table 2. Number of reported cases of each notifiable disease by week for the entire state for the current and the previous 6–8 weeks for comparison. Table 3. Number of reported cases of each notifiable disease for the past 4 weeks (current week and previous 3 weeks) and for comparison, the number of cases during the same period during the previous 5 years. Table 1 addresses disease occurrence by place. Tables 2 and 3 address disease occurrence by time. Together, these tables should provide an indication of whether an unusual cluster or pattern of disease is occurring. If such a pattern is detected, person characteristics might then be explored. A report for health-care providers does not need to be distributed as frequently and does not need to include all of the notifiable diseases. One approach might be to distribute a report every 6 months and include notifiable diseases that have demonstrated substantial change since the last report, with a discussion of possible causes for the change. Maps of the geographic distribution and figures illustrating the trends over time of selected diseases might be more appealing and informative to health-care providers than tables of frequencies. Information on the diagnosis and treatment of highlighted diseases might also be of interest to health-care providers. Reports for the media and public typically should be issued to inform them of outbreaks, of new diseases, or of diseases of particular concern. These reports should include basic information about the diseases, the location and frequency of their occurrence, and information on recognition, prevention, and treatment of the diseases. This is trial version www.adultpdf.com Public Health Surveillance Page 5-60 Exercise 5.6 State health department newsletters do not always go to all those who have a need to know. Even among those who receive the newsletter, some do not read it, and many others skim the articles and ignore the tables. In addition, depending on the timing of the laboratory report and publication deadlines, the information might be delayed by weeks or months. This information about finding rabid raccoons in a residential area is important for those who might be affected and for those who might be able to take preventive measures, including the following: • Other public health agencies (e.g., neighboring local health departments or animal control staff) — Contact and inform by telephone or e-mail message. • Health-care providers serving the population in the affected area — Contact and inform through a special mailing. • Veterinarians — Inform through a mailing so that they can be on alert for pets that might have come into contact with rabid wildlife; veterinarians can provide specimens, as appropriate, of both wild animals and pets to the state laboratory for testing for rabies. • The public — Inform by issuing press release to the media asking the public to avoid wild animals and to have their pets vaccinated. This is trial version www.adultpdf.com Public Health Surveillance Page 5-61 SELF-ASSESSMENT QUIZ Now that you have read Lesson 5 and have completed the exercises, you should be ready to take the self-assessment quiz. This quiz is designed to help you assess how well you have learned the content of this lesson. You may refer to the lesson text whenever you are unsure of the answer. Unless instructed otherwise, choose ALL correct answers for each question. 1. As described in this lesson, public health surveillance includes which activities? A. Data collection. B. Data analysis. C. Data interpretation. D. Data dissemination. E. Disease control. 2. Current public health surveillance targets which of the following? A. Chronic diseases. B. Communicable diseases. C. Health-related behaviors. D. Occupational hazards. E. Presence of viruses in mosquitoes. 3. Public health surveillance can be described primarily as which of the following? A. A method to monitor occurrences of public health problems. B. A program to control disease outbreaks. C. A system for collecting health-related information. D. A system for monitoring persons who have been exposed to a communicable disease. 4. Public health surveillance is only conducted by public health agencies. A. True. B. False. 5. Common uses and applications of public health surveillance include which of the following? A. Detecting individual persons with malaria so that they can receive prompt and appropriate treatment. B. Helping public health officials decide how to allocate their disease control resources. C. Identifying changes over time in the proportion of children with elevated blood lead levels in a community. D. Documenting changes in the incidence of varicella (chickenpox), if any, after a law requiring varicella vaccination took effect. This is trial version www.adultpdf.com Public Health Surveillance Page 5-62 6. Data collected through which of the following methods is commonly used for surveillance? A. Vital registration. B. Randomized clinical trials. C. Disease notifications. D. Population surveys. 7. Health-care providers might be important sources of surveillance data used by public health officials, and they should receive feedback to close the surveillance loop as a courtesy; however, the results almost never have any relevance to patient care provided by those health-care providers. A. True. B. False. 8. Vital statistics are important sources of data on which of the following? A. Morbidity. B. Mortality. C. Health-related behaviors. D. Injury and disability. E. Outpatient health-care usage. 9 Vital statistics provide an archive of certain health data. These data do not become surveillance data until they are analyzed, interpreted, and disseminated with the intent of influencing public health decision-making or action. A. True. B. False. 10. Key sources of morbidity data include which of the following? A. Environmental monitoring data. B. Hospital discharge data. C. Laboratory results. D. Notifiable disease reports. E. Vital records. 11 Notifiable disease surveillance usually focuses on morbidity from the diseases on the list and does not cover mortality from those diseases. A. True. B. False. 12. The list of diseases that a physician must report to the local health department is typically compiled by the . . . A. Local health department. B. State health department. C. Centers for Disease Control and Prevention (CDC). D. Council of State and Territorial Epidemiologists (CSTE). E. Medical licensing board. 13. A physician working in an emergency room in Town A, USA, has just examined a tourist from Southeast Asia with watery diarrhea. The physician suspects the man might have cholera. The physician should notify the . . . This is trial version www.adultpdf.com Public Health Surveillance Page 5-63 A. Local (town or county) health agency. B. State health department. C. Centers for Disease Control and Prevention (CDC). D. U.S. Department of State. E. Washington, D.C., embassy of country of origin (ask for health attaché). 14. Use the following choices for Questions 14a–e. A. Notifiable disease surveillance B. Surveillance for consumer product-related injuries C. Both. D. Neither. 14a. ____ State-based, with subsequent reporting to CDC. 14b. ____ Focused on identifying individual cases. 14c. ____ Can monitor trends over time. 14d. ____ Based on statistically valid sample. 14e. ____ Complete, unbiased reporting. 15. Evaluating and improving surveillance should address which of the following? A. Purpose and objectives of surveillance. B. Resources needed to conduct surveillance. C. Effectiveness of measures for controlling the disease under surveillance. D. Presence of characteristics of well-conducted surveillance. 16. Criteria for prioritizing health problems for surveillance include which of the following? A. Incidence of the problem. B. Public concern about the problem. C. Number of previous studies of the problem. D. Social and economic impact of the problem. 17. Use the following choices for Questions 17a–d. A. Surveillance based on a specific case definition for a disease (e.g., listeriosis). B. Syndromic surveillance based on symptoms, signs, or other characteristics of a disease, rather than specific clinical or laboratory diagnostic criteria. C. Both. D. Neither. 17a. ____ Watches for individual cases of disease of public health importance. 17b. ____ Watches for diseases that might be caused by acts of biologic or chemical terrorism. 17c. ____ Can watch for disease before a patient seeks care from a health-care provider. 17d. ____ Requires little effort on the part of the health department. This is trial version www.adultpdf.com Public Health Surveillance Page 5-64 18. Routine analysis of notifiable disease surveillance data at the state health department might include looking at the number of cases of a disease reported this week . . . A. and during the previous 2–4 weeks. B. and the number reported during the comparable weeks of the previous 2–5 years. C. simultaneously by age, race, and sex of the patient. D. by county. E. by county, divided by each county’s population (i.e., county rates). 19. One week, a state health department received substantially more case reports of a disease in one county than had been reported during the previous 2 weeks. No increase was reported in neighboring counties. Possible explanations for this increase include which of the following? A. An outbreak in the county. B. Batch reports. C. Duplicate reports. D. Increase in the county’s population. E. Laboratory error. 20. The primary reason for preparing and distributing periodic surveillance summaries is which of the following? A. Document recent epidemiologic investigations. B. Provide timely information on disease patterns and trends to those who need to know it. C. Provide reprints of MMWR articles, reports, and recommendations. D. Acknowledge the contributions of those who submitted case reports. 21. Use the following choices for Questions 21a–b. A. Predictive value positive. B. Sensitivity. C. Specificity. D. Validity. 21a. ____ Surveillance detected 23 of 30 actual cases of a disease. 21b. ____ Of 16 statistically significant aberrations (deviations from baseline) detected by syndromic surveillance, only one represented an actual outbreak of disease. 22. Underreporting is not a problem for detecting outbreaks of notifiable diseases because the proportion of cases reported tends to remain relatively stable over time. A. True. B. False. 23. Initiating surveillance for a public health problem or adding a disease to the notifiable disease list is justified for which of the following reasons? A. If it is a communicable disease with a high case-fatality rate. B. If the problem is new and systematically collected data are needed to characterize the disease and its impact on the public. C. If a program at CDC has recommended its addition to better understand national trends and patterns. D. To guide, monitor, and evaluate programs to prevent or control the problem. This is trial version www.adultpdf.com Public Health Surveillance Page 5-65 24. The case definition used for surveillance of a health problem should be the same as the case definition used for clinical (treatment) purposes. A. True. B. False. 25. A state health department decides to strengthen its notifiable disease reporting. The one best action to take is to … A. allow reporting through use of the Internet. B. require more disease-specific forms from local health departments. C. ensure that all persons with a responsibility to report understand the requirements and reasons for reporting and how reports will be used. D. reduce the number of diseases on the list. This is trial version www.adultpdf.com Public Health Surveillance Page 5-66 Answers to Self-Assessment Quiz 1. A, B, C, D. The term public health surveillance includes data collection, analysis, interpretation, and dissemination to help guide health officials and programs in directing and conducting disease control and prevention activities. However, surveillance does not include control or prevention activities themselves. 2. A, B, C, D, E. Current public health surveillance targets health-related conditions among humans, including chronic diseases (e.g., cancer), communicable diseases (e.g., those on the notifiable disease list), health-related behaviors, and occupationally related conditions (e.g., black lung disease and other pneumoconioses). Surveillance also focuses on indicators of disease potential (e.g., such diseases among animals as rabies) or presence of an infectious agent among animals or insects (e.g., West Nile virus among mosquitoes). 3. A. Public health surveillance can be thought of as one of the methods that a community has available to monitor the health among its population by detecting problems, communicating alerts as needed, guiding the appropriate response, and evaluating the effect of the response. Surveillance should not be confused with medical surveillance, which is monitoring of exposed persons to detect early evidence of disease. Public health surveillance is the continued watchfulness for public health problems; it is not a data- collection system. 4. B (False). The practice of surveillance is not limited to public health agencies. Hospitals, nursing homes, the military, and other institutions have long conducted surveillance of their populations. 5. A, B, C, D. Among the uses of surveillance are detecting individual cases of diseases of public health importance (e.g., malaria), supporting planning (e.g., priority setting), monitoring trends and patterns of health-related conditions (e.g., elevated blood lead levels), and supporting evaluation of prevention and control measures (e.g., a vaccination requirement). 6. A, C, D. Data collected through vital registration, disease notifications, and population surveys are commonly used for surveillance of health-related problems. Data from randomized clinical trials typically cover only a specially selected population and are used to answer specific questions about the effectiveness of a particular treatment. They are not useful for surveillance. 7. B (False). One of the important uses of surveillance data and one of the key reasons to close the surveillance loop by disseminating surveillance data back to health-care providers, is to provide clinically relevant information about disease occurrence, trends, and patterns. For example, health departments alert clinicians to the presence of new diseases (e.g., severe acute respiratory syndrome [SARS]) and provide information so that clinicians can make diagnoses. Health departments also advise clinicians about changing patterns of antibiotic resistance so that clinicians can choose the right treatment regimen. 8. B. Vital statistics refer to data on birth, death, marriage, and divorce. Therefore, vital This is trial version www.adultpdf.com Public Health Surveillance Page 5-67 statistics are the primary source of data on mortality, but not on morbidity (illness), behaviors, injury (other than fatal injuries), and health-care usage. Before development of population health surveys and disease registries and the use of health-care records to assess morbidity, vital statistics were the primary source of data on the health of populations. During recent years, administrative, financial, and other health-care–related records have supplemented the information from vital statistics, especially for assessing morbidity within populations. National, state, and local population-based health surveys, some of which are conducted on a regular or continuing basis, provide another important part of our view of the health of populations. 9. A (True). Vital statistics are usually thought of as an archive of births, deaths, marriages, and divorces. Vital statistics offices in health departments typically are not linked to disease prevention and control activities. However, surveillance for certain health problems might rely on vital statistics as its primary source of data. When these data undergo timely and systematic analysis, interpretation, and dissemination with the intent of influencing public health decision-making and action, they become surveillance data. 10. B, C, D. Sources of morbidity (illness) data include notifiable disease reports, laboratory data, hospital discharge data, outpatient health-care data, and surveillance for specific conditions (e.g., cancer). Vital records are an important source of mortality data, and even though a patient first gets sick from a disease before dying from it, vital records are not regarded as a source of data for the surveillance of morbidity from the disease. Environmental monitoring is used to evaluate disease potential or risk. 11. B (False). Notifiable disease surveillance targets occurrence or death from any of the diseases on the list. 12. B. The list of nationally notifiable diseases is compiled by the Council of State and Territorial Epidemiologists (CSTE) and the Centers for Disease Control and Prevention. The list of notifiable diseases that physicians must report to their state or local health department is set by the state, either by the state legislature, the state board of health, the state health department, the state health officer, or the state epidemiologist. CSTE votes on the diseases that should be nationally notifiable, but the states have the ultimate authority whether to add any newly voted diseases to their state list. 13. A or B, depending on the state. The agency that a physician should notify is determined by the state, just as the list of notifiable diseases is set by the state (see answer to question 12). The manner in which notification should occur and how rapidly reports should be made are also defined by the state and can vary by disease. For example, the state might require that a case of cholera be reported immediately by telephone or fax to the local or state health department, whereas reporting of varicella (chickenpox) might only be required monthly, by using a paper form. Regardless of the disease and reporting requirements, reporting should proceed through established channels. In certain states, physicians should notify the county health department, which will then notify the state health department, which will notify CDC, which will notify the World Health Organization. In states with no or limited local health departments, physicians are usually required to notify the state health department. The seriousness of the disease might influence how rapidly these communications take place but should not influence the sequence. This is trial version www.adultpdf.com [...]... for a disease attempts to identify individual cases of disease of public health importance, and syndromic surveillance, depending on its purpose, might also attempt to identify cases of disease of public health importance In certain situations, the goal of syndromic surveillance might be to identify clusters or outbreaks (more cases than expected) of disease rather than individual cases 17b C (Both)... positive is a function of both the sensitivity of surveillance and the prevalence of the disease (or prevalence of real outbreaks) 22 B (False) Underreporting is a serious problem for surveillance that relies on notifications Because the notifiable disease surveillance is supposed to identify individual cases of disease of public health importance, underreporting of even a single case of, for example, hepatitis... Thacker SB, Berkelman RL Public health surveillance in the United States Epidemiol Rev 1988;10:164-190 4 Communicable Disease Center Communicable Disease Center Activities 1952-1953 Atlanta: Department of Health, Education, and Welfare; 1953 Public Health Service Publication Number 391, p 17 5 World Health Organization Report of the technical discussions at the twenty-first World Health Assembly on 'national... reporting by a health- care provider Public Health Surveillance Page 5-68 This is trial version www.adultpdf.com 17d D Neither type of surveillance can function properly without attention and effort on the part of the health department Health department staff should review the case report forms and conduct follow-up of cases reported through surveillance based on specific case definitions for diseases Health. .. on 'national and global surveillance of communicable diseases.' Geneva: World Health Organization; 18 May 1968, p A21 6 Thacker SB, Stroup DF, Parrish RG, Anderson HA Surveillance in environmental public health: issues, systems, and sources Am J Public Health 1996;86:633–8 7 Vaughan JP, Morrow RH Manual of epidemiology for district health management Geneva: World Health Organization; 1989 8 Wegman DH... A, B, D Evaluation of surveillance for a health- related problem should include review of the purpose and objectives of surveillance, the resources needed to conduct surveillance for the problem, and whether the characteristics of well-conducted surveillance are present Because surveillance does not have direct responsibility for the control of the health problem, this is not part of evaluating a surveillance... 5):S1–12 13 Centers for Disease Control and Prevention Case Definitions for Infectious Conditions Under Public Health Surveillance MMWR 1997;46(No RR-10):1–55 14 Parrish RG, McDonnell SM Sources of health- related information In: Teutsch SM, Churchill RE, editors Principles and practice of Public Health Surveillance, 2nd ed New York: Oxford University Press; 2000, pp 30–75 15 Groves RM, Fowler FJ, Couper... response Early Aberration Reporting System (EARS) J Urban Health 2003;80:89–96 Public Health Surveillance Page 5-71 This is trial version www.adultpdf.com 17 Croner CM Public health GIS and the Internet Annu Rev Public Health 2003;24:57–82 18 Guerra M, Walker E, Jones C, Paskewitz S, Cortinas MR, Stancil A, Beck L, Bobo M, Kitron U Predicting the risk of Lyme disease: habitat suitability for Ixodes scapularis... 1999;5:607–25 38 Campos-Outcalt D, England R, Porter B Reporting of communicable diseases by university physicians Public Health Rep 1991;106:579–83 39 Marier R The reporting of communicable diseases Am J Epidemiol 1977;105:587–90 40 Konowitz PM, Petrossian GA, Rose DN The underreporting of disease and physicians' knowledge of reporting requirements Public Health Rep 1984;99:31–5 41 Hajjeh R, Reingold A, Weil... http://www.drugabuse.gov/DrugPages/MTF.html SAMHSA Office of Applied Studies Data Systems and Publications http://www.drugabusestatistics.samhsa.gov/ Summary of notifiable diseases – United States, 2004 http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5353a1.htm World Health Organization International Classification of Diseases, 10th revision http://www.who.int/classifications/icd/en/ Public Health Surveillance Page 5-74 This . disease. 4. Public health surveillance is only conducted by public health agencies. A. True. B. False. 5. Common uses and applications of public health surveillance include which of the following?. development of population health surveys and disease registries and the use of health- care records to assess morbidity, vital statistics were the primary source of data on the health of populations individual cases of disease of public health importance, and syndromic surveillance, depending on its purpose, might also attempt to identify cases of disease of public health importance. In certain