Males and females use benzodiazepines for nonmedical purposes equally. Some chiropractic groups still oppose attempts to limit or eliminate nonmedical exemptions to vaccination. The drug is a controlled substance in many countries, so nonmedical use is generally illicit. Among 12th graders, nonmedical prescription drug use is now second only to cannabis. In 1970, the government included nonmedical psychotherapists and psychoanalysts in the national health insurance program. Much of the current ketamine diverted for nonmedical use originates in China and India. Many diseases are preventable through simple, nonmedical methods. Systematic reviews have found no strong evidence about the impact of caesareans for nonmedical reasons. The term "masterly inactivity" is also used in nonmedical contexts. The data suggest vaccine refusal based on nonmedical reasons and personal belief exacerbated the outbreak. Nonmedical terms describing similar conditions include emotionless and impassive. Nonmedical use of zolpidem is increasingly common in the U.S., Canada, and the UK. All nonmedical visitors, except for Patton's wife, who had flown from the U.S., were forbidden.