Rates and risk factors of hypertension in adolescents and adults with sickle cell anaemia in Tanzania: 10 years' experience.

Data on the magnitude and risk factors for hypertension in sickle cell anaemia (SCA) are limited. A retrospective analysis of individuals with SCA aged ≥15 years enrolled from 2004-2014 at Muhimbili National Hospital, Tanzania was conducted to determine the prevalence, incidence and risk factors for hypertension. A total of 1013 individuals with SCA were analysed, of whom 571(56%) were females. The median age [interquartile range] was 17 [15-22] years. Four hundred and forty-one (44%) of the patients had relative hypertension [systolic blood pressure (SBP) 120-139 mmHg or diastolic blood pressure (DBP) 70-89 mmHg], and 79 (8%) had hypertension (SBP ≥ 140 mmHg or DBP ≥ 90 mmHg). The incidence of hypertension was 64/1000 person years of observation and the 5-year survival rate was 0·71 [95% confidence interval (CI): 0·67-0·75]. In multivariate analysis, age>18 years, Hazard ratio (HR) 1·50 (95% CI: 1·03-2·18); pulse pressure, HR 0·64 (95% CI: 0·42 to 0·98); pulse rate, 1·02 (95% CI: 1·01-1·03); body mass index (BMI), HR 1·08 (95% CI: 1·03-1·13); blood transfusion, HR 2·50 (95% CI: 1·01-6·21) and haemoglobin, HR 1·12 (95% CI: 1·05-1·33) were independently associated with hypertension. In conclusion, despite the younger age, hypertension in this population was higher than that reported in others studies. Age, BMI, pulse pressure and haemoglobin were independently associated with hypertension in SCA.

Rationale and design of mDOT-HuA study: a randomized trial to assess the effect of mobile-directly observed therapy on adherence to hydroxyurea in adults with sickle cell anemia in Tanzania.

BACKGROUND: Hydroxyurea (HU) has been demonstrated to be efficacious in reducing complications in individuals with sickle cell anemia (SCA) but poor adherence is a barrier. Directly Observed Therapy (DOT) has been shown to improve adherence in various chronic diseases but there is limited data in adults with SCA. METHODS AND DESIGN: To examine the effect of mobile-directly observed therapy (mDOT) on adherence to HU (mDOT-HuA) in adults with SCA at Muhimbili National Hospital in Tanzania. The mDOT-HuA study is a single centre, prospective, randomized, open label clinical trial. One-hundred individuals with SCA with haemoglobin SS genotype, aged ≥18 years, living in Dar es Salaam, able and willing to record and submit videos electronically will be included. Participants will be divided into two treatment arms; 50 in the standard monitoring (SM) arm will receive mobile phones and fixed dose HU therapy with standard monitoring; 50 in the mDOT arm will receive mobile phones, fixed dose HU therapy with standard monitoring and a mobile directly observed web based medication adherence monitoring system. The primary outcome is the proportion of participants achieving ≥80 % HU adherence compared between the two arms as assessed through medication possession ratio at the end of 3 months of treatment. REDCap, an open source software application will be used to collect data using clinical research forms. The proportions of adherence in the two arms will be compared by Fisher's exact test. Analysis of outcomes will have performed by both the intention-to treat and per-protocol methods. DISCUSSION: Should this study become sucessful, it will have the potential for the development of novel strategies for improving HU adherence in SCA. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02844673 , registered on 25tht July 2016 (retrospectively registered).

Hydroxyurea mobile directly observed therapy versus standard monitoring in patients with sickle cell anemia: a phase 2 randomized trial.

BACKGROUND: Sickle cell anemia (SCA) prevalence remains high in sub-Saharan Africa. Long-term treatment with hydroxyurea (HU) increases survival, however, poor adherence to treatment could limit effectiveness. Whilst HU treatment adherence is currently high, this might decrease over time. METHODS: We conducted a single-center, randomized, open-label, parallel group phase 2 controlled clinical trial to determine whether mobile Directly Observed Therapy (m-DOT) increases HU treatment adherence (NCT02844673). Eligible participants were adults with homozygous SCA. People on a chronic blood transfusion program, with hemoglobin (Hb) A levels greater than 20% of the total Hb, total Hb less than 4 g/dL, pregnant or HIV positive were excluded. After a 3-month pre-treatment period participants were randomized to either m-DOT or standard monitoring arm. All participants received smart mobile phones and were treated with HU (15 mg/kg) daily for three months. In the m-DOT arm, drug intake was video recorded on cell phone by the participant and the video sent to the study team. The primary objective was to evaluate the effect of m-DOT on adherence to HU treatment by medication possession ratio (MPR). RESULTS: Of the 86 participants randomized, 76 completed the trial (26.13 ± 6.97 years, 63.5 % female). Adherence was high (MPR > 95 %) in both groups, 29 (80.6 %) in m-DOT versus 37 (94.9 %) in the standard monitoring arm (P = 0.079). No HU treatment was withheld from participants due to safety concerns. CONCLUSIONS: m-DOT did not increase adherence to HU treatment. We recommend that further testing in larger trials with a longer follow up period be undertaken.

Sickle cell anemia (SCA) is an inherited blood disorder in which there is an abnormal protein inside red blood cells. This results in red blood cells becoming sickle shaped and more easily destroyed in the body. Long-term treatment with hydroxyurea can reduce the frequency of illness and hospitalization. However, often people do not manage to take their medication regularly when treatment is long-term. We therefore investigated whether people with SCA in sub-Saharan Africa are more likely to take hydroxyurea when they are remotely monitored than when they are not. Remote monitoring did not improve adherence. However, our study is small and was undertaken over a short time period when hydroxyurea had only recently become available to people with SCA. We propose further studies, to see if remote monitoring increases medication adherence in people with SCA in other scenarios.