[Observance and treatment follow-up]. 
The consequences of a bad observance of the treatment are serious for the patient and for the community: relapse, prolongation of the treatment, increase of the risk of death (x 4), prolongation of the period of contagiousness and development of multiresistant strains.  If a suitable antimycobacterial treatment was prescribed, observance is the essential element of success.  There is no consensual definition of a bad observance in the literature.  According to authors, bad observance can be defined as: 1) an interruption of treatment for at least two consecutive weeks; 2) drug intake inferior to 80% of the total prescribed amount.  The risk factors for bad observance are numerous.  The three principal ones frequently found in literature are: 1) absence of permanent residence (40 to 50% of bad observance); 2) alcoholism; 3) drug-addiction (especially i.v.).  Other factors are also reported: cultural and linguistic barriers, psychoses, difficulty to find adequate transport to come to consultation, inadequate consultation schedules or other conditions considered by the patient as more important than taking the treatment.