Assessment of the face validity of two pain scales in Kenya: a validation study using cognitive interviewing

Swahili versions of the NRS and FPS-R were developed by standard translation and back-translation. Cognitive interviews were performed with 15 patients at Moi Teaching and Referral Hospital in Eldoret, Kenya. Interview transcripts were analyzed on a question-by-question basis to identify major themes revealed through the cognitive interviewing process and to uncover any significant problems participants encountered with understanding and using the pain scales.Cognitive interview analysis demonstrated that participants had good comprehension of both the NRS and the FPS-R and showed rational decision-making processes in choosing their responses. Participants felt that both scales were easy to use. The FPS-R was preferred almost unanimously to the NRS.The face validity and acceptability of the Swahili versions of the NRS and FPS-R has been demonstrated for use in Kenyan patients. The broader application of these scales should be evaluated and may benefit patients who currently suffer from pain.Sub-Saharan Africa bears a disproportionate measure of the global burden of many diseases, as well as their attendant morbidities, including pain [1]. The prevalence of pain is amplified by lack of access to health facilities, late presentation, inadequate diagnosis, treatment unavailability, lack of medical education regarding pain control, and scarcity and underprescribing of opioids [1-4].Pain in sub-Saharan Africa has been studied primarily in three patient populations: HIV/AIDS patients, cancer patients, and palliative care patients. The prevalence of pain in African patients with HIV ranges from 59 to 98%, depending on disease stage, similar to the pain prevalence found in other HIV patient populations [5-8]. Cancer, increasingly prevalent in sub-Saharan Africa with rates of cancer expected to quadruple over the next 50 years, is also frequently associated with pain [9,10]. One study conducted in Uganda and South Africa found the prevalence of pain was 87.5% in cancer patie