W1 - Data Collection Lecture research topic
- 1. MED 7626: PREV MED 2B DATA COLLECTION AMA SCHOOL OF MEDICINE ACADEMICYEAR 2020-2021
- 2. OBJECTIVES • Differentiate between primary data and secondary data • Discuss the criteria for assessing quality of data • Identify sources of epidemiologic data • Describe the strengths and limitations of their use
- 3. DATA COLLECTION • In epidemiology, it is necessary to understand methods of data collection to be able to interpret information appropriately • It is also important to know the specific population, calendar period and frequency of updating data
- 4. TYPES OF DATA • PRIMARY DATA Information collected first hand by the researcher by query or observation • SECONDARY DATA Informed derived from previously collected data, which include those obtained from previous researches and existing records
- 5. PRIMARY DATA • ADVANTAGE Researcher has control over the quality of data since collection is planned and designed by the researcher • DISADVANTAGE Relatively more costly and time consuming to collect since they are collected directly from the study participants
- 6. SECONDARY DATA • ADVANTAGE Use of existing data saves time and cost since the researcher will no longer collect data from the study participants • DISADVANTAGE The researcher lacks control over the quality of the data collected since these have been collected previously for some other purpose/s
- 7. QUALITY AND UTILITY OF DATA • Nature of data • Availability • Completeness of population coverage • Strengths and limitations
- 8. ATTRIBUTES OF STATISTICAL DATA • Timeliness • Completeness • Accuracy • Precision • Relevance • Adequacy
- 9. ATTRIBUTES OF STATISTICAL DATA • Timeliness • Interval between the date of occurrence of the different events considered and the time the data is ready to be used or disseminated • Data which is available only after several months or years from the date of occurrence of events are no longer useful for planning and monitoring of programs
- 10. ATTRIBUTES OF STATISTICAL DATA • Completeness • Completeness of coverage • Completeness in accomplishing all the items in every form
- 11. ATTRIBUTES OF STATISTICAL DATA • Accuracy • How close the measurement or data is to its true value • “Do the data reflect the true situation?” • Compare the data with the expected trends, totals of other record systems • Compare the levels of data collected with those of other places with comparable conditions
- 12. ATTRIBUTES OF STATISTICAL DATA • Precision • Extent to which similar information is obtained when a measurement is performed or an observation is made more than once. • Repeatability or the consistency of the information that was collected
- 13. ATTRIBUTES OF STATISTICAL DATA • Relevance • Consistency of the data produced with the needs of the data users • Have a well-defined objectives for data collection – most basic step in attaining relevance
- 14. ATTRIBUTES OF STATISTICAL DATA • Adequacy • “Do the collected data provide all the basic information needed to meet the requirements of the user?” • Sometimes, the available data do not have enough details to provide a complete picture of the situation being considered • It is available but is not processed or presented in a form which is consistent with the user’s needs
- 15. NATURE OF DATA • Where the data came from Vital records, case registries, hospital and clinical cases • Affects types of statistical analyses and inferences
- 16. AVAILABILITY OF DATA • Refers to the investigator’s ability to gain access to the data
- 17. COMPLETENESS OF POPULATION COVERAGE • Representativeness or external validity Generalizability of the findings to the population from which data have been taken • Thoroughness All cases of a health phenomenon, including sub-clinical cases, are identified
- 18. STRENGTHS AND LIMITATIONS • Utility of data for various types of epidemiologic research • Inaccuracy of information (incomplete diagnostic information and case duplication)
- 19. CONFIDENTIALITY, DATA SHARING AND RECORD LINKAGE • Adequate safeguards on data privacy and confidentiality of information must be considered, taken by the investigator/s • Data sharing • Voluntary release of information by an investigator or institution to another for purposes of scientific research • E.g. Linkage of large data sets and pooling of multiple studies done in meta-analyses • Issue on primary investigator’s potential loss of control over intellectual property
- 20. CONFIDENTIALITY, DATA SHARING AND RECORD LINKAGE • Record linkage • Joining data from two or more sources, such as employment records and mortality data
- 21. SPECIFIC DATA USEFUL IN STUDIES • Data on vital events (natality and mortality) • Disease statistics • Data on physiologic and/or pathologic conditions • Statistics on health resources and services • Statistics pertaining to environment • Demographic data • Socio-cultural data
- 22. CENSUS • Complete enumeration of a population • Best source of data on population size and distribution according to age, sex, geographical location, and other demographic variables • Basis in estimating or projecting population size • Published in several volumes
- 23. VITAL RECORDS Death certificate (Mortality statistics) Information Completeness / Accuracy Fact of death Satisfactory (Death unlikely to go unrecorded Cause of death Not satisfactory
- 26. VITAL RECORDS Death certificate (Mortality statistics) • Immediate cause of death (COD) – the final disease, injury or complication directly causing death • Antecedent COD – can lead to the stated immediate COD • Underlying COD – the disease or injury that initiated the chain of morbid events that lead directly and inevitably to death; MOST important
- 28. VITAL RECORDS Death certificate (Mortality statistics) • Issues/Problems • Diagnostic inaccuracy • Unavailability of cause of death statements • Lack of standardization of diagnostic criteria
- 29. VITAL RECORDS Death certificate (Mortality statistics) • Completeness and acceptability of the Cause-of-Death Statement in Death Certificates (Tolabing, et al. 2007) • 19% completely filled up • Among the 3 items, the underlying cause was the least filled up item (28%) • 5% underlying cause were unacceptable entries
- 30. VITAL RECORDS Death certificate (Mortality statistics) • Causes of problems • Medically unattended deaths • Lack of training of certifying physicians on cause of death (COD) • Attitude of physicians
- 31. VITAL RECORDS Death certificate (Mortality statistics) • Other factors affecting accuracy of Cause of Death • Easily diagnosed cases are most likely to be recorded accurately • Longer period between the onset of disease and death can affect accuracy of cause • Diseases to which a stigma is attached may be under-reported • Incorrect codes assigned to disease
- 32. VITAL RECORDS Death certificate (Mortality statistics) • Indicator of disease frequency • Obtain leads about etiologic agents by identifying demographic sub-groups at high risk, facilitating study of trends in disease occurrence over time • Enable comparisons of disease occurrence in different populations and geographic areas
- 33. VITAL RECORDS Birth certificate Information Completeness / Accuracy Fact of birth Satisfactory (Births unlikely to go unrecorded) Conditions of child at birth Satisfactory (Observation) Conditions of mother during pregnancy Not satisfactory (Recall)
- 35. MORBIDITY SURVEYS • Collect data on the health status of a population group • Sample population (representative sample) • Gather more comprehensive information than routinely collected data • Possible limitations • Not all samples will participate • Sometimes only one person will answer for the whole group → inaccurate information
- 36. MORBIDITY SURVEYS Philippine National Demographic and Health Survey • Done every five years since 1968 to monitor and evaluate programs on population,family planning and health that are implemented by the government • Provide information on fertility, family planning and health
- 37. MORBIDITY SURVEYS National Nutrition Survey • Done every five years to determine and evaluate the food intakes, nutrition and health status of filipinos • Provide official statistics on food, nutrition and health situations of the country
- 38. MORBIDITY SURVEYS OperationTimbang Plus • Done every year to identify and locate malnourished children by measuring height and weight of preschoolers 0 to 71 months old (or below six years old) • Provide information in the effectiveness of local nutrition program
- 39. SCREENING SURVEYS • Conducted on an ad hoc basis for infectious and chronic diseases • Neighborhood screening clinics and health fair • Sample population • Possible limitation – non-representative nature of sample
- 40. REGISTRIES • Centralized database for collection of information about a disease • Newly recognized cases are entered and maintained in a file until recovery, death or migration • Source of data for duration of illness, outcome of illness, incidence and prevalence, and natural history of disease • Possible limitation – data reporting and collection depends on staff
- 41. REPORTABLE DISEASE STATISTICS (NOTIFIABLE) • Health facilities and health practitioners are legally required to report certain cases of certain diseases • System of reporting is in place • Public Health Surveillance and Informatics Division under Department of Health (DOH) • Field Health Service Information System (FHSIS) • Philippine Integrated Disease Survey and Response (PIDSR)
- 45. REPORTABLE DISEASE STATISTICS (NOTIFIABLE) CATEGORY 1: Immediately reportable disease syndromes / events • Acute flaccid paralysis “hot case” • Anthrax • Human avian influenza • Severe acute respiratory syndrome (SARS) • Adverse event following immunization • Any disease outbreak • Any clustering of patients with similar disease, symptoms, or syndromes • Meningococcal disease
- 46. REPORTABLE DISEASE STATISTICS (NOTIFIABLE) CATEGORY 1: Immediately reportable disease syndromes / events (Immediate reporting upon laboratory confirmation) • Poliomyelitis • Cholera • Measles • HIV / AIDS • COVID-19 infection
- 47. REPORTABLE DISEASE STATISTICS (NOTIFIABLE) CATEGORY II :Weekly reportable diseases / syndromes / events • Acute bloody diarrhea • Acute hemorrhagic fever syndrome • Acute viral hepatitis • Acute flaccid paralysis • Bacterial meningitis • Cholera • Dengue • Diphtheria
- 48. REPORTABLE DISEASE STATISTICS (NOTIFIABLE) CATEGORY II :Weekly reportable diseases / syndromes / events (continued) • Influenza • Japanese encephalitis • Leptospirosis • Malaria • Neonatal and non-neonatal tetanus • Paralytic shellfish poisoning • Pertussis • Rabies • Typhoid and paratyphoid fever
- 49. HOSPITAL DATA • In-patient and out-patient records • Possible limitations • Does not represent a specific population • Types of information are not standardized • Socio-economic composition of patients
- 50. ONLINE SOURCES OF EPIDEMIOLOGIC DATA • Global Outbreak Alert and Response Network • Department under World Health Organization (WHO) dedicated to monitoring outbreaks of communicable disease worldwide
- 52. ONLINE SOURCES OF EPIDEMIOLOGIC DATA • Public Health Mapping • Part of the WHO Communicable Disease Surveillance and Response site • Provides data for communicable diseases
- 54. ONLINE SOURCES OF EPIDEMIOLOGIC DATA • Weekly Epidemiological Record • Distributed weekly by the WHO • Gives the most up-to-date epidemiological figures for infectious and communicable diseases worldwide
- 56. ONLINE SOURCES OF EPIDEMIOLOGIC DATA • WHO Classification • Criteria for disease, disability and health that are used for epidemiologic processes
- 58. ONLINE SOURCES OF EPIDEMIOLOGIC DATA • Global Health Observatory Data • Health related statistics for more than 1,000 indicators
- 60. METHODS OF DATA COLLECTION • Sample survey • Observations • Interview • Focus group discussion (FGD) • Questionnaire
- 61. REFERENCES • Agosto, H. 2018. Lecture on Sources of Data. Department of Epidemiology and Biostatistics, College of Public Health, University of the Philippines (UP) Manila • Aschengrau, Ann and George Seage III. 2014. Sources of Public Health Data. Essentials of Epidemiology in Public Health. Jones & Bartlett Learning, LLC, Burlington, MA. • Centers for Disease Control and Prevention, US Department of Health and Human Services. August 2004. Instructions for Completing the Cause-Of-Death Section of the Death Certificate. Retrieved from http://www.cdc.gov/nchs/data/dvs/blue_form.pdf
- 62. REFERENCES • Department of Health. Jun 2019. Field Health Services Information System Annual Report 2018. Retrieved from https://www.doh.gov.ph/sites/default/files/publications/FHSIS_Annual_2018_Final.pdf • Department of Health.Apr 2014. Manual of Procedures for the Philippine Integrated Disease Surveillance and Response, 3rd edition. Retrieved from https://www.doh.gov.ph/sites/default/files/publications/PIDSRMOP3ED_VOL1_2014.pdf • Mendoza, Ophelia, PhD, et.Al. (2010). Foundations of Statistical Analysis for the Health Sciences. Manila : Buencamino Press. • University of Kent. 2016. Statistical and epidemiological sources. Retrieved from https://www.kent.ac.uk/library/subjects/medicine/epidemiology.html
- 63. THANKYOU!