A nationwide study on hospitalizations aimed to analyse pathologies affecting drug users
BACKGROUND Health consequencies of drug use is a complex phenomenon that has been studied mainly analysing particular subgroups of people, such as patients accessing to Emergency Rooms.
In the present study, exhaustive data on Italian Hospital Discharges have been analysed to identify the pathologies most related to the use of illegal drugs.
METHODS Data from the National Hospital Discharge Database (NHDB) were analysed to study the characteristics of hospitalized persons; for each patient, demographic data (e.g. gender, date and place of birth) as well as the "primary" diagnosis and up to five "secondary" diagnoses are recorded; diagnoses are codified according to the World Health Organization (WHO) International Classisfication of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM); among disgnoses, we considered in particular the use of the following substances: opioids, cocaine, sedatives, cannabinoids and "others, not specified"; in particular, a focus on cannabinoids, cocaine and opioid users, as well as "poly-drug users" was performed. The study period is 2005-2019. We considered as "incident cases" to keep into consideration the patients having among hospitalization diagnoses the use of at least one substance, in their first hospital admission, occurred during the study period. Incidence Rates for age and gender were calculated. In order to study "comorbidities" of these patients, the followin main pathologies were considered: infectous diseases, neoplasms, pathologies of cardiovascular, respiratory, digestive and urinary systems; Standardadized Hospitalization Rates by gender and age were calculated, as well as their 95% Confidence Interval.
RESULTS i) Drug related hospitalization trends were studied by gender: although men are far more than women, the trends were similar, and they showed a greater increase for cannabis since 2010 and since 2012 for cocaine and other substances .
ii) regarding comorbidities, none of them resulted significant in cannabis users ( their hospitalization profile resulted similar to "general population"); one only was significant in cocaine users (infectous diseases, whereas two comorbidities (infectous diseases and diseases of respiratory system) were significant for male opioid users and four comorbidities for female opioid users (infectous diseases and diseases of respiratory, digestive and urinary system) .
CONCLUSION Some main findings did confirm results obtained from less exhaustive data sources, while novel information, in particular regarding new substances and comorbidities were obtained, suggesting further analyses that the authord have planned to perform.