The study was carried out by researchers from Carnegie Mellon University and Harvard School of Public Health, the Kenya Medical Research Institute (KEMRI), and the University of Oxford.
They used data captured during a 2009 national survey conducted by Financial Sector Deepening Kenya, a financial services support programme in Nairobi. More than 30,000 people aged over 16 — from nearly 650 communities across the country — took part in the survey.
Participants were asked about their mobile phone usage, ownership and monthly airtime expenditure, and questions relating to their demographic background.
The study, published in PloS One (25 April), found that levels of mobile phone usage and ownership across the country varied greatly.
However Abdisalan Noor, one of the paper's authors who is based at KEMRI, told SciDev.Net that low ownership levels did not necessarily reflect low usage, as many subscribers reported sharing a single handset.
"[We] found that although only 44 per cent of individuals owned a mobile phone, 85 per cent reported [having used] a mobile phone, with results showing high levels of phone-sharing," Noor said.
"Many people in Kenya own sim cards but don't have handsets, so they share handsets with [each other]."
Despite varied levels of ownership, the study found a strong appetite for mobile phone use in Kenya.
Amy Wesolowski, another author on the paper, said that improvements to national coverage should be geared towards rural Kenya, to help reduce geographical differences in mobile phone ownership.
The authors were particularly interested in mobile technology's potential to relay health messages to health workers and the general population, she added.
Leonida Mutuku, a researcher at iHub Research in Nairobi, said the findings would be especially useful to designers of mobile phone applications.
"If one knows access patterns for shared and single-owned phones, one can then develop [applications] which take these patterns into account," Mutuku told SciDev.Net.
Mutuku also commented on another of the study's findings — that Kenyan women and young people were less likely to own mobile phones than men. This finding could help organisations devise plans to target and engage with these groups more effectively, she said.
However, Mutuku also warned that data from the 2009 survey could already be out of date, because mobile phone ownership levels in Kenya was constantly changing.
Heterogeneous Mobile Phone Ownership and Usage Patterns in Kenya PLoS ONE 7(4): e35319 doi:10.1371/journal.pone.0035319