Association of knowledge and attitudes with practices of misuse of tranquilizers: A cohort study in Spain.

Background: Tranquilizer misuse represents a growing international public health problem with heavy social and economic consequences. We aimed to identify the psychosocial determinants of this misuse practice, focusing on modifiable factors including knowledge and attitudes towards these medications.

Methods: A prospective cohort study involving 847 adults accompanying children in primary care clinics was carried out in Spain. A validated Knowledge, Attitudes and Practices (KAP) questionnaire on tranquilizer use was self-administered at baseline, and then participants were followed-up bimonthly. A misuse event was defined as unprescribed intake of tranquilizers, storing/sharing leftovers of tranquilizers, and/or not adhering to the prescribed treatment period, timing or dosage. Poisson regression models were applied to estimate adjusted Incidence Rate Ratios (IRRs) of misuse and their 95 % Confidence Intervals (CIs).

Findings: Individuals' personal attitudes towards tranquilizers and treating physicians are strongly associated with the misuse of these drugs. These attitudes include: individuals' acceptance of taking tranquilizers to improve sleeping [IRR: 5.10 (95 %CI: 2.74-9.48)], to work better [IRR: 2.04 (95 %CI: 1.05-3.99)], or for recreational purposes [IRR: 1.85 (95 %CI: 1.04-3.32)]; willingness to prolong the course of tranquilizer treatment without medical consultation [IRR: 2.45 (95 %CI: 1.46-4.13)]; agreeing on storing tranquilizers for possible future need [IRR: 5.07 (95 %CI: 2.73-9.40)]; and untrusting the physician's decision about tranquilizer prescription [IRR: 1.92 (95 %CI: 1.12-3.30)]. The level of knowledge is marginally associated with tranquilizer misuse.

Conclusions: There is a strong association between individuals' attitudes towards tranquilizers and the misuse practices of these drugs. Educational interventional studies could help reduce the incidence of tranquilizer misuse.