Correlates of Non-Medical Prescription Drug Misuse Among a Treatment-Seeking Population: A Comparison with Illicit Drug Users

Prescription drugs (PD) undoubtedly help people with various physical or psychiatric ailments. Nevertheless, they are often diverted and misused (use without prescription or for purposes/in ways not intended by the prescriber). This study compared the sociodemographic and clinical correlates of those who misused PDs, used illegal drugs and co-ingested both, to identify those who were at a high risk of misusing these drugs. Retrospective analysis of the treatment outcome monitoring (TOM) data for the period of 2013–2017 identified 1369 subjects for the study; 295 patients presented with PD use disorder (PDUD alone), 811 with illegal drug use disorder (IDUD alone), and 263 had both PDUD and IDUD. The study sample included treatment seeking population (Singaporeans and permanent residents). TOM data included data collected through direct interviews (addiction severity, quality of life) and from the clinical case notes (diagnosis, co-morbidities, socio demographic information, etc.). The most commonly misused prescription and illegal drugs were benzodiazepines (63.1%) and heroin (63.4%), respectively. Those who co-ingested both PD and illegal drugs (PDUD+IDUD) had a significantly higher addiction severity score, lower quality of life and higher psychiatric co-morbidities than that of IDUD alone at baseline. When compared to Chinese patients, Malay and Indian patients had lower odds (p < 0.05) of PDUD alone and PDUD+IDUD than Chinese patients; divorcees had higher odds of PDUD+IDUD than those who were married. Those with primary and secondary qualifications had higher odds (2.1 and 2.9 times, respectively) of PDUD+IDUD than those with tertiary qualification and those in managerial or professional roles had higher odds of PDUD alone than those who were unemployed. Gender, ethnicity, marital status, education and occupational classes were associated with PDUD and IDUD. These characteristics can be helpful to identify those who are at the risk of PDUD and incorporate strict prescription monitoring to their care.