Adapted Motivational Interviewing to improve uptake of glaucoma treatment in Bauchi, Nigeria

Background: Glaucoma is a major cause of irreversible blindness in Africa due to its high prevalence, early age of onset and aggressive course. Patients often present very late and have poor awareness and limited access to services with limited treatment options to lower the intraocular pressure. When treatment is available there is often poor acceptance of surgery, the preferred treatment in Africa. To prevent blindness from glaucoma a behaviour change intervention is required to increase awareness and encourage acceptance of and adherence to treatment and follow up. Motivational interviewing (MI) was selected and adapted for this study as it has shown promise in adherence to treatment in other chronic diseases, and non professional counsellors can be trained to deliver it. To improve treatment options transscleral diode laser cyclophotoablation was introduced before the trial started Methods: Design: single site pragmatic randomized controlled trial with 1:1 allocation to one session of MI or enhanced usual care. MI was adapted for the local context and language was carried out using an interview guide generated following qualitative research. Participants allocated to MI were randomly allocated to one of two interviewers. Usual care was routine explanation by an ophthalmologist and an educational pamphlet. After the interview, a 12-item Working Alliance Inventory short questionnaire was administered to patients and interviewers to assess the collaborative relationship. The primary outcome of the trial was the proportion of participants who accepted and underwent surgery or laser treatment within two months of the date given. Laser treatment was performed using diode 810nm laser G-probes under retrobulbar anaesthesia and standard procedures. Patients were reviewed on day one, one week and at 1, 4, 6 and 12 months when IOP and visual acuity were measured. Results 276 patients participated in the trial: 135 (49%) were assigned to MI and 141 to usual care. 53% of patients in the MI group underwent treatment compared with 45% in the usual care group (risk ratio 1.2; 95% confidence interval (CI) 0.9-1.6). Overall acceptance was 49% higher than before the trial. Analysis of WAI scores showed similar scores for participants and interviewers overall. Interviewer and participant scores had high reliability coefficients (94.3% and 93.3% respectively) with good correlation when combined using Cronbach's alpha (93.9%). In the laser treatment study, data from 204 eyes treated were included in the study. Before treatment mean IOP was 39mmHg being 12, 11, 15, 18, 19 and 19mmHg on day one, at one week, and 1, 4, 6 and 12 months respectively. At 12 months 77 (72.6%) eyes (106/107 with data) had IOPs <22mmHg. At 12 months 83 (78%) eyes retained (70 eyes, 66%) or had improved (13 eyes, 12%) visual acuity; 25 eyes (23%) lost acuity. 17 eyes were retreated. No eyes had persistent hypotony. Conclusion The results do not support the introduction of this adapted MI tool to increase acceptance of glaucoma surgery in Africa as we observed only a small increase in acceptance compared with usual care, which was not statistically significant. Although only 1 in 2 patients accepted surgery or laser in this trial this is a much higher proportion than observed in other studies. In this trial the majority of participants underwent laser treatment, which is less invasive, repeatable and cheaper than trabeculectomy. The diode laser treatment appears to be a good alternative to surgery in this setting as it is acceptable, gives good IOP control and good preservation of vision at one year. Trials of different modalities of laser as a primary treatment for glaucoma in Africa are warranted.