Treatment Default amongst Patients with Tuberculosis in Urban Morocco: Predicting and Explaining Default and Post-Default Sputum Smear and Drug Susceptibility Results

Imad Cherkaoui,Ouafae Lahlou,Radia Sabouni,Alexander C Billioux,Jamal Eddine Bourkadi,Kelly E Dooley,Darya Kizub,Rajae El Aouad,Kenza Bennani,Iraqi Ghali,Abderrahmane Benmamoun,Daniela Flavia Hozbor

doi:10.1371/journal.pone.0093574

Abstract

SettingPublic tuberculosis (TB) clinics in urban Morocco.ObjectiveExplore risk factors for TB treatment default and develop a prediction tool. Assess consequences of default, specifically risk for transmission or development of drug resistance.DesignCase-control study comparing patients who defaulted from TB treatment and patients who completed it using quantitative methods and open-ended questions. Results were interpreted in light of health professionals’ perspectives from a parallel study. A predictive model and simple tool to identify patients at high risk of default were developed. Sputum from cases with pulmonary TB was collected for smear and drug susceptibility testing.Results91 cases and 186 controls enrolled. Independent risk factors for default included current smoking, retreatment, work interference with adherence, daily directly observed therapy, side effects, quick symptom resolution, and not knowing one’s treatment duration. Age >50 years, never smoking, and having friends who knew one’s diagnosis were protective. A simple scoring tool incorporating these factors was 82.4% sensitive and 87.6% specific for predicting default in this population. Clinicians and patients described additional contributors to default and suggested locally-relevant intervention targets. Among 89 cases with pulmonary TB, 71% had sputum that was smear positive for TB. Drug resistance was rare.ConclusionThe causes of default from TB treatment were explored through synthesis of qualitative and quantitative data from patients and health professionals. A scoring tool with high sensitivity and specificity to predict default was developed. Prospective evaluation of this tool coupled with targeted interventions based on our findings is warranted. Of note, the risk of TB transmission from patients who default treatment to others is likely to be high. The commonly-feared risk of drug resistance, though, may be low; a larger study is required to confirm these findings.

Highlights

Tuberculosis (TB) remains a global health threat, with 8.6 million cases and 1.3 million TB-related deaths in 2012 [1]
We present results of a concurrent study of risk factors for TB treatment default based on patient interviews and compare these findings to responses given by healthcare providers
What are the implications of treatment default? In our study, 72% of patients with pulmonary TB who defaulted had a sputum sample that was smear positive for TB when they returned to care, indicating high risk of transmission to others; drug resistance, was rare

Summary

Introduction

Tuberculosis (TB) remains a global health threat, with 8.6 million cases and 1.3 million TB-related deaths in 2012 [1]. Treatment default is defined by the World Health Organization (WHO) as treatment interruption of at least two months. Treatment default is complex and is influenced by patient, treatment, systems, and community-level factors that vary by setting [5,6,7,8]. To design effective programmatic interventions to address TB treatment default requires in-depth evaluations at the local level [9,10]. Patients judged to be at high risk of default based on local risk factors received specialized services, and treatment completion improved markedly [11]

Methods

Results

Discussion

Conclusion