3.15 Evaluation Questions 3

Expected time: 30 minutes

1. Define population-based and hospital-based surveillance programmes.

Population-based programmes collect data from the entire resident population in a defined geographic area. Hospital-based programmes collect data from births that occur in preselected hospitals in a province, country or region.

2. Why are prevalence estimates drawn from hospital-based surveillance programmes less likely to be accurate?

Prevalence estimates drawn from hospital-based programmes only provide the estimate for the participating hospitals and cannot be generalized to a broader population. There is an exception, however; in countries where nearly all births take place in the hospital and all hospitals in a state, country or region participate, and where there is no selective inflow of cases from outside the state/country/region, those hospital-based programmes can accurately represent true prevalence.

3. What are some factors to consider when deciding whether to implement a population-based or hospital-based surveillance programme in a country?

Available resources AND/OR capacity

4. Which of the following is NOT a type of case ascertainment method?

  1. Active
  2. Independent
  3. Passive
  4. Hybrid

b. Independent

5. Which of the following is NOT a characteristic of passive case ascertainment?

  1. The burden of work is placed on the data source staff.
  2. The data are not verified by surveillance staff, resulting in lower data quality and the potential for less accuracy.
  3. This method can be resource and personnel intensive but usually results in improved data quality.

c. This method can be resource and personnel intensive but usually results in improved data quality.

6. True or false: Using a single data source may improve data quality.


7. True or false: New, smaller programmes should consider starting with a small number of easily recognizable, major external congenital anomalies and then expand to include additional anomalies as the programme gains experience, creates awareness and is assigned more resources.


8. List some differences between the two methods for describing congenital anomalies in the data-collection process.

Verbatim descriptions allow for more detail, which may be necessary for accurate diagnosis and during the case-management process. Checkbox descriptions are predetermined categories of selected congenital anomalies. Checkbox descriptions alone may be insufficient for high data quality. It is more useful to include further options for categorizing anomalies.

9. True or false: Inclusion of live births alone is a significant limitation that can lead to unreliable rates and trends, particularly for conditions with a high rate of loss prior to 28 weeks.


10. Define stillbirth according to WHO.

Fetal deaths at ≥28 weeks of gestation or weighing ≥1000 g if gestational age is unknown.

11. Which is an advantage of paper-based collection methods?

  1. They may be cost-effective for low-resource settings.
  2. They may be more prone to human error, since transcribing is required.
  3. They may require more time to collect and transmit data.

a. They may be cost-effective for low-resource settings.

12. True or false: Incidence is usually used to describe the occurrence of congenital anomalies.


13. Define prevalence.

Prevalence is a measure of the total number of existing cases of a disease for a given point in time or period, and in a given population, regardless of whether or not they are new cases.

14. True or false: The three top attributes of data quality are timeliness, accuracy and completeness.