Inter-informant agreement and prevalence estimates for substance use disorders: direct interview versus family history method.

OBJECTIVES: Family studies typically use multiple sources of information on each individual including direct interviews and family history information. The aims of the present study were to: (1) assess agreement for diagnoses of specific substance use disorders between direct interviews and the family history method; (2) compare prevalence estimates according to the two methods; (3) test strategies to approximate prevalence estimates according to family history reports to those based on direct interviews; (4) determine covariates of inter-informant agreement; and (5) identify covariates that affect the likelihood of reporting disorders by informants. METHODS: Analyses were based on family study data which included 1621 distinct informant (first-degree relatives and spouses) - index subject pairs. RESULTS: Our main findings were: (1) inter-informant agreement was fair to good for all substance disorders, except for alcohol abuse; (2) the family history method underestimated the prevalence of drug but not alcohol use disorders; (3) lowering diagnostic thresholds for drug disorders and combining multiple family histories increased the accuracy of prevalence estimates for these disorders according to the family history method; (4) female sex of index subjects was associated with higher agreement for nearly all disorders; and (5) informants who themselves had a history of the same substance use disorder were more likely to report this disorder in their relatives, which entails the risk of overestimation of the size of familial aggregation. CONCLUSION: Our findings have important implications for the best-estimate procedure applied in family studies.

Cannabis use trajectories among Swiss adolescents

Introduction: Swiss data indicate that one fifth of current 16-20 yearold cannabis users do not use tobacco and seem to do better than those smoking both substances. The aim of this research is to assess the substance use trajectories of cannabis users who do not use tobacco and those who use both substances from age 17 to age 23. Methods: Using data from the TREE longitudinal data base, 328 out of 1796 youth 18.3%; 45% females) who smoked cannabis only (Group CAN; N = 46; 36% females) or concurrently with tobacco (Group CANTAB; N = 284; 46% females) at T1 (2001; age 17) were followed at T4 (2004; age 20) and T7 (2007; age 23). Two additional outcome groups were included at T4 and T7: those using only tobacco (Group TOB) and those not using any of these substances (Group NONE). Data were analyzed separately by gender. Results: Females in group CAN at T1 were as likely to be in group TOB (35%) or NONE (35%) at T4 and the percentages increased to 41% and 47%, respectively, at T7. Males in group CAN at T1 were more likely to be in group TOB at T4 (33%) and T7 (61%) than in group NONE (23% and 15%, respectively). Females in group CANTOB at T1 were mainly in group TOB at T4 (52%) and T7 (61%), while males in CANTOB at T1 remained mainly in the same group at T4 (75%) and T7 (61%). Only 10% of females and 5% of males in group CANTOB at T1 were in group NONE at T4 and 15% and 12%, respectively, at T7. Conclusions: Adolescents using only cannabis are globally less likely to continue using cannabis in young adulthood than those using both substances, although a fair percentage (specially males) switch to tobacco use. This result confirms previous research indicating that nicotine dependence and persistent cigarette smoking may be the main public health consequences of cannabis use. A gender difference arises among those using tobacco and cannabis at age 17: while females become mainly tobacco smokers, the majority of males continue to use both substances. Although these results could be explained by a substitution effect, teenagers using both substances seem to have gone beyond the experimentation phase and should be a motive for concern.

What factors influence long-term antidepressant use in primary care? Findings from the Australian diamond cohort study.

BACKGROUND: Antidepressants are one of the most commonly prescribed drugs in primary care. The rise in use is mostly due to an increasing number of long-term users of antidepressants (LTU AD). Little is known about the factors driving increased long-term use. We examined the socio-demographic, clinical factors and health service use characteristics associated with LTU AD to extend our understanding of the factors that may be driving the increase in antidepressant use. METHODS: Cross-sectional analysis of 789 participants with probable depression (CES-D≥16) recruited from 30 randomly selected Australian general practices to take part in a ten-year cohort study about depression were surveyed about their antidepressant use. RESULTS: 165 (21.0%) participants reported <2 years of antidepressant use and 145 (18.4%) reported ≥2 years of antidepressant use. After adjusting for depression severity, LTU AD was associated with: single (OR 1.56, 95%CI 1.05-2.32) or recurrent episode of depression (3.44, 2.06-5.74); using SSRIs (3.85, 2.03-7.33), sedatives (2.04, 1.29-3.22), or antipsychotics (4.51, 1.67-12.17); functional limitations due to long-term illness (2.81, 1.55-5.08), poor/fair self-rated health (1.57, 1.14-2.15), inability to work (2.49, 1.37-4.53), benefits as main source of income (2.15, 1.33-3.49), GP visits longer than 20min (1.79, 1.17-2.73); rating GP visits as moderately to extremely helpful (2.71, 1.79-4.11), and more self-help practices (1.16, 1.09-1.23). LIMITATIONS: All measures were self-report. Sample may not be representative of culturally different or adolescent populations. Cross-sectional design raises possibility of "confounding by indication". CONCLUSIONS: Long-term antidepressant use is relatively common in primary care. It occurs within the context of complex mental, physical and social morbidities. Whilst most long-term use is associated with a history of recurrent depression there remains a significant opportunity for treatment re-evaluation and timely discontinuation.

The clinical use of quantitative ultrasound (QUS) in the detection and management of osteoporosis

For the detection and management of osteoporosis and osteoporosis-related fractures, quantitative ultrasound (QUS) is emerging as a relatively low-cost and readily accessible alternative to dual-energy X-ray absorptiometry (DXA) measurement of bone mineral density (BMD) in certain circumstances. The following is a brief, but thorough review of the existing literature with respect to the use of QUS in 6 settings: 1) assessing fragility fracture risk; 2) diagnosing osteoporosis; 3) initiating osteoporosis treatment; 4) monitoring osteoporosis treatment; 5) osteoporosis case finding; and 6) quality assurance and control. Many QUS devices exist that are quite different with respect to the parameters they measure and the strength of empirical evidence supporting their use. In general, heel QUS appears to be most tested and most effective. Overall, some, but not all, heel QUS devices are effective assessing fracture risk in some, but not all, populations, the evidence being strongest for Caucasian females over 55 years old. Otherwise, the evidence is fair with respect to certain devices allowing for the accurate diagnosis of likelihood of osteoporosis, and generally fair to poor in terms of QUS use when initiating or monitoring osteoporosis treatment. A reasonable protocol is proposed herein for case-finding purposes, which relies on a combined assessment of clinical risk factors (CR.F) and heel QUS. Finally, several recommendations are made for quality assurance and control.