Survey research with a random digit dial national mobile phone sample in Ghana: Methods and sample quality

PLoS One. 2018 Jan 19;13(1):e0190902. doi: 10.1371/journal.pone.0190902. eCollection 2018.


Introduction: Generating a nationally representative sample in low and middle income countries typically requires resource-intensive household level sampling with door-to-door data collection. High mobile phone penetration rates in developing countries provide new opportunities for alternative sampling and data collection methods, but there is limited information about response rates and sample biases in coverage and nonresponse using these methods. We utilized data from an interactive voice response, random-digit dial, national mobile phone survey in Ghana to calculate standardized response rates and assess representativeness of the obtained sample.

Materials and methods: The survey methodology was piloted in two rounds of data collection. The final survey included 18 demographic, media exposure, and health behavior questions. Call outcomes and response rates were calculated according to the American Association of Public Opinion Research guidelines. Sample characteristics, productivity, and costs per interview were calculated. Representativeness was assessed by comparing data to the Ghana Demographic and Health Survey and the National Population and Housing Census.

Results: The survey was fielded during a 27-day period in February-March 2017. There were 9,469 completed interviews and 3,547 partial interviews. Response, cooperation, refusal, and contact rates were 31%, 81%, 7%, and 39% respectively. Twenty-three calls were dialed to produce an eligible contact: nonresponse was substantial due to the automated calling system and dialing of many unassigned or non-working numbers. Younger, urban, better educated, and male respondents were overrepresented in the sample.

Conclusions: The innovative mobile phone data collection methodology yielded a large sample in a relatively short period. Response rates were comparable to other surveys, although substantial coverage bias resulted from fewer women, rural, and older residents completing the mobile phone survey in comparison to household surveys. Random digit dialing of mobile phones offers promise for future data collection in Ghana and may be suitable for other developing countries.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Bias
  • Cell Phone*
  • Data Collection / methods
  • Data Collection / standards
  • Data Collection / statistics & numerical data
  • Female
  • Ghana
  • Health Surveys / methods*
  • Health Surveys / standards
  • Health Surveys / statistics & numerical data
  • Humans
  • Male
  • Middle Aged
  • Sample Size
  • Young Adult

Grants and funding

The Communicate for Health program was made possible by the support of the American people through the United States Agency for International Development (Cooperative Agreement AID-641-A-15-00003) to FHI 360. The contents of this manuscript are the sole responsibility of the authors and do not necessarily reflect the views of USAID or the United States government. The funder provided full or partial salary support for ES, EAA, EY, RL, and KLew, provided contractual support to KL’Engle, and provided contractual support to CT and NLH through VOTO Mobile. The funder had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. The specific roles of these authors are articulated in the ‘Authors’ contributions’ section.