A Positive Deviance Nutrition Education Intervention to Improve Nutritional Intake, Sputum Conversion and Clinical Signs among Tuberculosis Patients in Kericho County, Kenya

Abstract

Tuberculosis (TB) is one of the leading causes of death worldwide. In the recent years, Kenya has recorded a high prevalence of TB and a greater proportion of patients with negative treatment outcomes. This study addressed the challenge of negative treatment outcomes through a positive deviance-based nutrition education intervention for patients with active TB. The objectives of the study were: to determine the practices associated with TB treatment outcomes; the influence of nutrition education on nutritional status; the influence of the intervention on sputum smear conversion; and the effects of the nutrition intervention on clinical signs among TB patients. A quasi-experimental with pre-post-test design was adopted. Positive deviance inquiry was used to identify best practices among 216 persons who had completed treatment within the year preceding the study. The best practices were adopted for the intervention. For the intervention and control arms, 192 newly diagnosed TB patients were recruited through multistage cluster sampling. The sample was distributed such that 96 were enrolled in the intervention arm and 96 in the control arm. The intervention included fortnightly nutrition education on nutrient-dense meal, dietary diversity, and the provision of nutrient-rich meals for six months. Nutritional status and nutrient intake were determined through anthropometric measurements and food frequency questionnaires. Sputum smear microscopy and clinical signs were also assessed at critical points. Data analysis was conducted using R to obtain independent t tests, chi-square, logistic regression, and difference-in-difference (DID). Anthropometric data were converted into BMI and categorized into nutritional status indicators using WHO cut-offs, while food frequency data were converted into daily nutrient yields and compared against Recommended Dietary Allowances (RDA). The significance level was set at p < 0.05. The results revealed that socio-demographic factors, health-seeking, lifestyle (alcohol, tobacco), low baseline BMI, comorbidities, and lack of adherence support were significantly linked to negative treatment outcome (p < 0.01). The intervention group showed significant increases in BMI at 2nd, 5th, and 6th months (p = 0.01, 0.01, 0.001). Adherence to recommended dietary intake for energy, protein, carbohydrates, vitamins A and C, zinc, and selenium improved remarkably (AOR = 1.84 – 2.14, p < 0.01). Sputum conversion rates in the intervention group exceeded 90% at all critical points of study, compared to 85.2% in the control group (p < 0.01). In the control group, only fat intake improved sputum conversion at month two (β = 0.15, p = 0.026). In the intervention group, higher energy (β = 0.76–0.91, p < 0.007), protein (β = 0.67–0.95, p < 0.004), carbohydrates (β = 0.17–0.47, p < 0.004), vitamin A (β = 0.75–0.88, p < 0.003), vitamin C (β = 0.80–0.89, p < 0.001), zinc (β = 0.67–0.82, p < 0.005), and selenium (β = 0.53–0.79, p < 0.007) were significantly associated with sputum conversion. Clinical signs such as cough and weight loss improved significantly in the intervention group. Higher odds of improvement were observed at 2nd, 5th, and 6th months of the study with AOR = 1.98 (95% CI: 1.02 - 3.82; p = 0.041), 1.79 (95% CI: 1.03 - 3.10; p = 0.039), and 2.46 (95% CI: 1.29 - 4.71; p = 0.034), respectively (p < 0.05). A possible limitation for this study was recalling bias and social desirability in diet reporting. In conclusion, multiple ‘best’ practices influenced treatment outcomes. The intervention improved nutritional status, sputum conversion and clinical signs and therefore enhanced treatment response. xix The study recommends that: context specific factors should be used to design targeted interventions; nutrition education should be individually tailored to the patient needs with specific focus on locally available, and nutrient-dense foods rich in vitamins A and C, zinc, and selenium; nutritional support should be strengthened to accelerate sputum smear conversion during the treatment period. Further longitudinal research is recommended to assess the sustained effects of nutrition education interventions on the improvement and stability of clinical signs.