CLINICAL HANDBOOK OF SCHIZOPHRENIA

128 II. ASSESSMENT AND DIAGNOSISsame risks seen in the general population, such as higher rates of cardiovascular diseaseand higher rates of chronic obstructive pulmonary disease.Assessment of cigarette dependence requires asking patients at each visit if theysmoke, and determining the frequency and amount of smoking. An abstinence period istypically defined by no more than five cigarettes from the start of the abstinence period.A standard abstinence question is “Have you smoked at all since (date of abstinence)?”,with the following possible responses: (1) No, not a puff; (2) one to five cigarettes; or (3)more than five cigarettes. For responses 1 and 2, a biochemical test is usually helpful toconfirm a classification of abstinence.A standardized questionnaire such as the Fagerstrom Test of Nicotine Dependence(FTND) can also be used to assess nicotine dependences. This scale is a six-item measureof behaviors related to dependence on nicotine. Items ask about time elapsed beforesmoking the first cigarette of the day, difficulty refraining from smoking, increased smokingin the morning, and the most difficult cigarette of the day to give up. The FTNDshows good internal consistency and construct validity. Scores range from 0 to 10, withscores greater than 3 indicating dependence.A Smokerlyzer may be used with patients to assess the level of carbon monoxide inexpired air. Carbon monoxide (CO) measures of less than 9 parts per million (ppm) canbe used to confirm abstinence. Alternative biochemical measures, such as cotinine concentrationlevels (saliva, urine, plasma), may be used. The cutoff for urine is 50 ng/ml,and 15 ng/ml for saliva. Cotinine levels do not discriminate between nicotine ingested bycigarettes and that derived from replacement products. It is therefore important to inquireabout use of these products prior to testing nicotine levels. Although testing for thepresence of cotinine is the preferred biochemical method to determine abstinence, COverification can also determine use. This method only detects recent smoking. However,most smokers return to daily smoking if they relapse, and CO levels can be used for confirmationof cigarette use.INFECTIOUS DISEASES: HIV AND HEPATITIS CIndividuals with schizophrenia are at increased risk of HIV infection compared to thegeneral population. Current prevalence rates for persons with schizophrenia rangebetween 2 and 5%, with rates of 2% in nonmetropolitan areas and 5% in observedurban areas. This prevalence is around eight times the overall estimate for the U.S.population. Women with schizophrenia are at even greater increased risk for HIV; themale-to-female ratio is 4:3, compared to 5:1 in the general population. A number offactors, such as increased injection drug use and unsafe sexual practices, may contributeto increased HIV rates in this population. Studies have also shown that personswith severe mental illnesses are more likely to engage in high-risk behaviors and lesslikely to modify their behaviors.Patients with a dual diagnosis of schizophrenia and substance use disorder have a22% greater chance of having HIV than patients without a mental illness. However,those without a substance abuse disorder are 50% less likely than people without a mentalillness to contract HIV. This may be due to less socialization because of negative symptomssuch as withdrawal and apathy (Himelhoch et al., 2007).In addition to increased risk for HIV, high-risk behaviors and injection drug use contributeto higher rates of hepatitis C virus (HCV) in persons with schizophrenia. Rates ofHCV in this population range from 9 to 20%, at a rate 11 times greater than that in thegeneral population. Among those infected with HCV, 90% will develop chronic infections,and 20% will progress to hepatic cirrhosis.