Data quality in the age of lean data


by Daniel Ramirez-Raftree, MERL Tech support team.

Evolving data collection methods call for evolving quality assurance methods. In their session titled Data Quality in the Age of Lean Data, Sam Schueth of Intermedia, Woubedle Alemayehu of Oxford Policy Management, Julie Peachey of the Progress out of Poverty Index, and Christina Villella of MEASURE Evaluation discussed problems, solutions, and ethics related to digital data collection methods. [Bios and background materials here]

Sam opened the conversation by comparing the quality assurance and control challenges in paper assisted personal interviewing (PAPI) to those in digital assisted personal interviewing (DAPI). Across both methods, the fundamental problem is that the data that is delivered is a black box. It comes in, it’s turned into numbers and it’s disseminated, but in this process alone there is no easily apparent information about what actually happened on the ground.

During the age of PAPI, this was dealt with by sending independent quality control teams to the field to review the paper questionnaire that was administered and perform spot checks by visiting random homes to validate data accuracy. Under DAPI, the quality control process becomes remote. Survey administrators can now schedule survey sessions to be recorded automatically and without the interviewer’s knowledge, thus effectively gathering a random sample of interviews that can give them a sense of how well the sessions were conducted. Additionally, it is now possible to use GPS to track the interviewers’ movements and verify the range of households visited. The key point here is that with some creativity, new technological capacities can be used to ensure higher data quality.

Woubedle presented next and elaborated on the theme of quality control for DAPI. She brought up the point that data quality checks can be automated, but that this requires pre-survey-implementation decisions about what indicators to monitor and how to manage the data. The amount of work that is put into programming this upfront design has a direct relationship on the ultimate data quality.

One useful tool is a progress indicator. Here, one collects information on trends such as the number of surveys attempted compared to those completed. Processing this data could lead to further questions about whether there is a pattern in the populations that did or did not complete the survey, thus alerting researchers to potential bias. Additionally, one can calculate the average time taken to complete a survey and use it to identify outliers that took too little or too long to finish. Another good practice is to embed consistency checks in the survey itself; for example, making certain questions required or including two questions that, if answered in a particular way, would be logically contradictory, thus signaling a problem in either the question design or the survey responses. One more practice could be to apply constraints to the survey, depending on the households one is working with.

After this discussion, Julie spoke about research that was done to assess the quality of different methods for measuring the Progress out of Poverty Index (PPI). She began by explaining that the PPI is a household level poverty measurement tool unique to each country. To create it, the answers to 10 questions about a household’s characteristics and asset ownership are scored to compute the likelihood that the household is living below the poverty line. It is a simple, yet effective method to evaluate household level poverty. The research project Julie described set out to determine if the process of collecting data to create the PPI could be made less expensive by using SMS, IVR or phone calls.

Grameen Foundation conducted the study and tested four survey methods for gathering data: 1) in-person and at home, 2) in-person and away from home, 3) in-person and over the phone, and 4) automated and over the phone. Further, it randomized key aspects of the study, including the interview method and the enumerator.

Ultimately, Grameen Foundation determined that the interview method does affect completion rates, responses to questions, and the resulting estimated poverty rates. However, the differences in estimated poverty rates was likely not due to the method itself, but rather to completion rates (which were affected by the method). Thus, as long as completion rates don’t differ significantly, neither will the results. Given that the in-person at home and in-person away from home surveys had similar completion rates (84% and 91% respectively), either could be feasibly used with little deviation in output. On the other hand, in-person over the phone surveys had a 60% completion rate and automated over the phone surveys had a 12% completion rate, making both methods fairly problematic. And with this understanding, developers of the PPI have an evidence-based sense of the quality of their data.

This case study illustrates the the possibility of testing data quality before any changes are made to collection methods, which is a powerful strategy for minimizing the use of low quality data.

Christina closed the session with a presentation on ethics in data collection. She spoke about digital health data ethics in particular, which is the intersection of public health ethics, clinical ethics, and information systems security. She grounded her discussion in MEASURE Evaluation’s experience thinking through ethical problems, which include: the vulnerability of devices where data is collected and stored, the privacy and confidentiality of the data on these devices, the effect of interoperability on privacy, data loss if the device is damaged, and the possibility of wastefully collecting unnecessary data.

To explore these issues, MEASURE conducted a landscape assessment in Kenya and Tanzania and analyzed peer reviewed research to identify key themes for ethics. Five themes emerged: 1) legal frameworks and the need for laws, 2) institutional structures to oversee implementation and enforcement, 3) information systems security knowledge (especially for countries that may not have the expertise), 4) knowledge of the context and users (are clients comfortable with their data being used?), and 5) incorporating tools and standard operating procedures.

Based in this framework, MEASURE has made progress towards rolling out tools that can help institute a stronger ethics infrastructure. They’ve been developing guidelines that countries can use to develop policies, building health informatic capacity through a university course, and working with countries to strengthen their health information systems governance structures.

Finally, Christina explained her take on how ethics are related to data quality. In her view, it comes down to trust. If a device is lost, this may lead to incomplete data. If the clients are mistrustful, this could lead to inaccurate data. If a health worker is unable to check or clean data, this could create a lack of confidence. Each of these risks can lead to the erosion of data integrity.

Register for MERL Tech London, March 19-20th 2018! Session ideas due November 10th.

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