Commonly detected chemicals include, but are not limited to the following; * Cocaine * Amphetamine * Methamphetamine * Methylone * Ecstasy * Heroin * Alcohol * Nicotine * Caffeine * Ketamine * Opioids * Antidepressants * Antipsychotics * Antimicrobials * Antihistamines * Aritificial sweeteners Temporal comparisons By analyzing samples taken across different time points, day-to-day or longer term trends can be assessed. This approach has illustrated trends such as increased consumption of alcohol and recreational drugs on weekends compared to weekdays. A temporal<unk>  study in Washington measured<unk>  samples in Washington before, during and after cannabis legalisation. By comparing cannabis consumption in<unk>  with sales of cannabis through legal outlets, the study showed that the opening of legal outlets led to a decrease in the market share of the illegal market. Spatial comparisons Differences in chemical consumption amongst different locations can be established when comparable methods are used to analyse<unk>  samples from different locations. The European Monitoring Centre for Drugs and Drug Addiction conducts regular multi-city tests in Europe to estimate the consumption of illegal drugs. Data from these monitoring efforts are used alongside more traditional monitoring methods to understand geographical changes in drug consumption trends.
Wastewater-based epidemiology
Computational epidemiology
Spatial epidemiology
Epidemiology in Country Practice
Economic epidemiology
Real world data
Analysis of clinical trials
Diagnosis-related group