Clinically unintended medication switches and inability to prescribe preferred medications under Medicare Part D.

Medicare Part D has expanded medication access; however, there is some evidence that dually eligible psychiatric patients have experienced medication access problems. The aim of this study was to characterize medication switches and access problems for dually eligible psychiatric patients and associations with adverse events, including emergency department visits, hospitalizations, homelessness, and incarceration. Reports on 986 systematically sampled, dually eligible patients were obtained from a random sample of practicing psychiatrists. A total of 27.6% of previously stable patients had to switch medications because clinically indicated and preferred refills were not covered or approved. An additional 14.0% were unable to have clinically indicated/preferred medications prescribed because of drug coverage/approval. Adjusting for case-mix, switched patients (p = 0.0009) and patients with problems obtaining clinically indicated medications (p = 0.0004) had significantly higher adverse event rates. Patients at greatest risk were prescribed a medication in a different class or could not be prescribed clinically-indicated atypical antipsychotics, other antidepressants, mood stabilizers, or stimulants. Patients with problems obtaining clinically preferred/indicated antipsychotics had a 17.6 times increased odds (p = 0.0039) of adverse events. These findings call for caution in medication switches for stable patients and support prescription drug policies promoting access to clinically indicated medications and continuity for clinically stable patients.

Suicidality is associated with medication access problems in publicly insured psychiatric patients.

BACKGROUND: Beginning January 1, 2006, the Medicare Part D prescription drug benefit shifted drug coverage from Medicaid to the new Medicare Part D program for patients who were eligible for both Medicare and Medicaid benefits ("dual-eligibles"). These patients were randomly assigned to a private Part D plan and came under specific formulary and utilization management procedures of the plan in which they were enrolled. OBJECTIVE: To examine the relationship between physician-reported medication switches, discontinuations, and other access problems and suicidal ideation or behavior among "dual-eligible" psychiatric patients. METHOD: Data were collected in 3 cross-sectional cycles in 2006 (January-April, May-August, and September-December) as part of the National Study of Medicaid and Medicare Psychopharmacologic Treatment Access and Continuity using through-the-mail, practice-based survey research methods. Data from the third cycle, representing all events since January 1, 2006, were used for these analyses. A national sample of psychiatrists randomly selected from the AMA Masterfile provided clinically detailed data on 1 systematically selected, dual-eligible psychiatric patient (N = 908). Propensity score analyses adjusted for patient sociodemographics, treatment setting, diagnoses, and psychiatric symptom severity. RESULTS: Patients who experienced medication switches, discontinuations, and other access problems had 3 times the rate of suicidal ideation or behavior compared with patients with no access problems (22.0% vs 7.4%, P < .0001). Mean odds ratios and excess probabilities were highest for patients who were clinically stable but were required to switch medications (31.8%; mean OR = 4.87, mean P = 8.92(-5), excess probability = 0.21). Patients who experienced discontinuations (26.4%; mean OR = 2.13, mean P = 2.12(-2), excess probability = 0.12), other access problems (18.7%; mean OR = 3.01, mean P = 1.03(-5), excess probability = 0.15), and multiple access problems (22.3%; mean OR = 2.88, mean P = 4.10(-5), excess probability = 0.14) also had significantly increased suicidal ideation or behavior. CONCLUSION: Increased occurrences of suicidal ideation or behavior appear to be associated with disruptions in patient medication access and continuity. Clinicians need to be aware of the possibility of increased suicidality when, for administrative reasons, a clinically stable patient's medication regimen is altered. Dual-eligible psychiatric patients represent a highly vulnerable group with a substantial burden of illness; these findings underscore the need to provide special protections for this population.

Medicaid medication access problems and increased psychiatric hospital and emergency care.

OBJECTIVES: To quantify the extent to which Medicaid programs may incur increased psychiatric emergency department and hospital use associated with clinically unintended medication discontinuations, gaps, switches and other access problems attributed to prescription drug coverage and management. METHOD: This study uses clinically detailed, physician-reported data. A total of 4866 psychiatrists in 10 states were randomly selected from the AMA Masterfile; 62% responded and 32% treated Medicaid patients and reported on 1625 systematically selected Medicaid patients. Propensity score multivariate models assessed predicted probabilities and mean number of emergency department visits and hospital days. RESULTS: Many patients (46.0%, S.E.=1.3%) had medication access problems reported during the past year, including discontinuing or switching medications or inability to obtain clinically indicated prescriptions because of drug coverage or management. The expected number of emergency department visits was estimated to be 73.8% higher among patients with medication access problems reported compared to matched patients without access problems reported. Among acute stay inpatients, the expected number of hospital days was 71.7% higher for patients with medication access problems reported. CONCLUSIONS: Medication access problems may have significant implications for Medicaid programs. The potential indirect costs of these policies in psychiatric and social services utilization should be considered in addition to direct pharmacy costs.

The dimensionality of alcohol use disorders and alcohol consumption in a cross-national perspective.

AIMS: To replicate the finding that there is a single dimension trait in alcohol use disorders and to test whether the usual 5+ drinks for men and 4+ drinks for women and other measures of alcohol consumption help to improve alcohol use disorder criteria in a series of diverse patients from emergency departments (EDs) in four countries. DESIGN: Cross-sectional surveys of patients aged 18 years and older that reflected consecutive arrival at the ED. The Composite International Diagnostic Interview Core was used to obtain a diagnosis of DSM-IV alcohol dependence and alcohol abuse; quantity and frequency of drinking and drunkenness as well as usual number of drinks consumed during the last year. SETTING: Participants were 5195 injured and non-injured patients attending seven EDs in four countries: Argentina, Mexico, Poland and the United States (between 1995-2001). FINDINGS: Using exploratory factor analyses alcohol use disorders can be described as a single, unidimensional continuum without any clear-cut distinction between the criteria for dependence and abuse in all sites. RESULTS: from item response theory analyses showed that the current DSM-IV criteria tap people in the middle-upper end of the alcohol use disorder continuum. Alcohol consumption (amount and frequency of use) can be used in all EDs with the current DSM-IV diagnostic criteria to help tap the middle-lower part of this continuum. Even though some specific diagnostic criteria and some alcohol consumption variables showed differential item function across sites, test response curves were invariant for ED sites and their inclusion would not impact the final (total) performance of the diagnostic system. CONCLUSIONS: DSM-IV abuse and dependence form a unidimensional continuum in ED patients regardless of country of survey. Alcohol consumption variables, if added, would help to tap patients with more moderate severity. The DSM diagnostic system for alcohol use disorders showed invariance and performed extremely well in these samples.

First-year Medicare Part D prescription drug benefits: medication access and continuity among dual eligible psychiatric patients.

OBJECTIVE: This study provides national data on medication access and continuity problems experienced during the first year of the Medicare Part D prescription drug program, which was implemented on January 1, 2006, among a national sample of Medicare and Medicaid "dual eligible" psychiatric patients. METHOD: Practice-based research methods were used to collect clinician-reported data across the full range of public and private psychiatric treatment settings. A random sample of psychiatrists was selected from the American Medical Association Physician Masterfile. Among these physicians, 1,490 provided clinically detailed data on a systematically selected sample of 2,941 dual eligible psychiatric patients. RESULTS: Overall, 43.3% of patients were reported to be unable to obtain clinically indicated medication refills or new prescriptions in 2006 because they were not covered or approved; 28.9% discontinued or temporarily stopped their medication(s) as a result of prescription drug coverage or management issues; and 27.7% were reported to be previously stable on their medications but were required to switch medications. Adjusting for case mix to control for sociodemographic and clinical confounders, the predicted probability of an adverse event among patients with medication access problems was 0.64 compared to 0.36 for those without access problems (P < .0001). All prescription drug utilization management features studied were associated with increased medication access problems (P < .0001). Adjusting for patient case mix, patients with "step therapy" (P < .0001), limits on medication number/dosing (P < .0001), or prior authorization (P < .0001) had 2.4 to 3.4 times the increased likelihood of an adverse event. CONCLUSIONS: More effective Part D policies and management practices are needed to promote clinically safer and appropriate pharmacotherapy for psychiatric patients to enhance treatment outcomes.

Part D and dually eligible patients with mental illness: medication access problems and use of intensive services.

OBJECTIVE: This study examined the occurrence of medication access problems and use of intensive mental health services after the transition in January 2006 from Medicaid drug coverage to Medicare Part D for persons dually eligible for Medicaid and Medicare benefits. METHODS: Psychiatrists randomly selected from the American Medical Association's Physicians Masterfile reported on experiences of one systematically selected dually eligible patient (N=908) in the nine to 12 months after Part D implementation. Propensity score matching was used to compare use of psychiatric emergency department care and inpatient care between individuals who experienced a problem accessing a psychiatric medication after Part D and those who did not. RESULTS: Approximately 44% of dually eligible patients were reported to have experienced a problem accessing medications. The likelihood of visiting an emergency department was significantly higher for those who experienced an access problem than for those who did not (mean odds ratio=1.75, mean p=.003). There was no difference in number of emergency department visits or hospitalizations for those who had at least one. CONCLUSIONS: Many dually eligible patients had difficulty accessing psychiatric medications after implementation of Part D. These patients were significantly more likely to visit psychiatric emergency departments than patients who did not experience difficulties. These findings raise concerns about possible negative effects on quality of care. Additional study is needed to understand the full effects of Part D on outcomes and functioning as well as treatment costs for this population.

Medicare Part D prescription drug benefits and administrative burden in the care of dually eligible psychiatric patients.

OBJECTIVE: With implementation of Medicare Part D, concerns were raised that patients with severe mental illness who were dually eligible for both Medicaid and Medicare benefits would be at clinical risk. In addition to concerns about medication access and continuity, there were concerns about administrative burden for physicians and their staffs. This study aimed to quantify the amount of administrative burden for psychiatrists and their staff related to Medicare Part D prescription drug plan administration in a national sample of dually eligible psychiatric patients and to identify factors associated with increased burden. METHODS: A total of 5,833 psychiatrists were randomly selected from the American Medical Association's Physicians Masterfile. Responses were obtained from 64% (N=3,247) with a mailed survey using practice-based survey research methods during the first four months of Medicare Part D implementation (January to April 2006); 1,183 psychiatrists met eligibility requirements. RESULTS: Psychiatrists and their staff spent 45 minutes in administrative tasks for every one hour of direct patient care for dually eligible patients. Drug plan features, including prior authorization and preferred drug formularies, and medication access problems were associated with increased administrative time. CONCLUSIONS: Results of this study indicate several drug plan features and medication access problems related to Part D implementation were associated with significant increases in administrative burden for psychiatrists and their staff, which may result in less time for direct patient care. Given the vulnerability of this high-risk population, this increased administrative burden may pose a significant risk to the overall quality of care for psychiatric patients.

Parity and the use of out-of-network mental health benefits in the FEHB program.

Two current congressional bills mandate parity for benefits for mental disorders with benefits for medical/surgical conditions in private insurance when mental health benefits are provided; the bills differ in regard to benefit levels and access to out-of-network coverage. This study assessed clinicians' and beneficiaries' participation in managed care networks in the national capital area under the Federal Employees Health Benefits (FEHB) parity program. Approximately one-third of the clinicians studied participated in FEHB networks, and only 44 percent of FEHB patients received care from network clinicians. Out-of-network mental health benefits are an important policy consideration to ensure access to mental health treatment under parity proposals.

ADHD and gender: are risks and sequela of ADHD the same for boys and girls?

BACKGROUND: Research comparing treatment-referred boys and girls with attention-deficit/hyperactivity disorder (ADHD) has yielded equivocal results. Contradictory findings may be associated with differential referral practices or unexplored interactions of gender with ADHD subtypes. METHOD: We examined possible gender differences in ADHD and its subtypes among children aged 4 to 17 in a representative community sample (N = 1896) in Puerto Rico. Caretakers provided information through the Diagnostic Interview Schedule for Children (version IV) and a battery of impairment, family relations, child problems, comorbidity and treatment measures. RESULTS: ADHD was 2.3 times more common in boys than girls, but with one exception there was little evidence that the patterns of associations of ADHD with correlates were different for boys and girls. The exception was school suspension, which was more common among ADHD boys than girls. Additional gender interactions were found when ADHD subtypes were considered. Among those with combined type (n = 50), boys were more likely to be comorbid with mood disorders than girls. For those with the inattentive type (n = 47), girls were more likely to be comorbid with anxiety disorders than boys. CONCLUSIONS: Our findings lend cross-cultural generalizability to recent reports that gender does not interact with correlates for ADHD overall, but that it may play a role in subtypes.

ADHD correlates, comorbidity, and impairment in community and treated samples of children and adolescents.

Patterns of correlates, comorbidity and impairment associated with attention-deficit hyperactivity disorder (ADHD) in children and youth were examined in representative samples from the community and from treatment facilities serving medically indigent youth in Puerto Rico. Information from caretakers and youths was obtained using the Diagnostic Interview Schedule for Children, (version IV), measures of global impairment, and a battery of potential correlates. In the community (N = 1,896) and the treated samples (N = 763), 7.5 and 26.2% of the children, respectively, met criteria for DSM-IV ADHD in the previous year. Although the prevalence rates and degree of impairment differed, the general patterns of correlates, comorbidity and impairment were similar in both populations. The exceptions were associated with conduct disorder, anxiety, impairment in the ADHD comorbid group, and age factors that appeared to be related to selection into treatment.

Medication access and continuity: the experiences of dual-eligible psychiatric patients during the first 4 months of the Medicare prescription drug benefit.

OBJECTIVE: This study attempted to systematically assess the experiences of Medicare and Medicaid "dual-eligible" psychiatric patients, including evaluating patients' access to medications and the administrative functioning of the program, during the first 4 months of the Medicare Part D prescription drug benefit. METHOD: Psychiatrists (N=5,833) were randomly selected from the American Medical Association's Physicians Masterfile. After exclusion of those not practicing and with undeliverable addresses, 64% responded; 35% met study eligibility criteria of treating at least one dual-eligible patient during their last typical workweek and reported clinically detailed information on one systematically selected patient. RESULTS: A total of 53.4% had at least one medication access problem to report between Jan. 1 and April 30, 2006. Although 9.7% experienced improved medication access, 22.3% discontinued or temporarily stopped taking medication because of prescription drug coverage or management issues, and 18.3% were previously stable but were required to switch medications. Among those with medication access problems, 27.3% experienced a significant adverse clinical event; 19.8% had an emergency room visit. Most drug plan features studied, including preferred drug/formulary lists, prior authorization, medication dosing/number limits, "fail-first" protocols, and requirements to switch to generics, were associated with significantly higher rates of medication access problems. CONCLUSIONS: The findings indicate consequential medication access problems for psychiatric patients during the implementation of Medicare Part D. Although Centers for Medicare and Medicaid Services policies were enacted to ensure access to protected classes of psychopharmacologic medications, the high rates of medication access problems observed indicate further refinement of these policies is needed.

Developing the diagnostic and statistical manual V: what will "statistical" mean in DSM-V?

In February of 2004, the American Psychiatric Institute for Research and Education (APIRE) hosted a Launch and Methodology Conference to discuss the role statistics might play in the eventual revision of the Fourth Edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) and the Ninth Edition of the International Classification of Diseases (ICD9). The conference consisted of talks on specific topics by statisticians and epidemiologists from North America and Great Britain, followed by group discussion by experts in nosology and psychopathology. We report here on the development of specific themes related to the future interaction between statisticians and nosologists in DSM-V development that arose as a result of that meeting. The themes are related to (1) the nature of the statistician/nosologist interaction; (2) specific areas of concern in that interaction, and (3) the use of novel and complex statistical methods to challenge and inspire new avenues of thinking among nosologists.

Comorbidity patterns in routine psychiatric practice: is there evidence of underdetection and underdiagnosis?

OBJECTIVE: The purpose of this study is to present data on the rates of diagnosis and patterns of Axis I comorbidity treated by psychiatrists in routine psychiatric practice, ascertained by practicing psychiatrists, and compare them with those ascertained through structured interview in a national sample of individuals treated in the specialty mental health sector for evidence of underdetection or underdiagnosis of comorbid disorders in routine psychiatric practice. METHODS: Data on 2117 psychiatric patients gathered by 754 psychiatrists participating in the 1997 and 1999 American Psychiatric Institute for Research and Education's Practice Research Network's Study of Psychiatric Patients and Treatments (SPPT) were analyzed, assessing psychiatrist-reported rates of Axis I disorders and comorbidities. SPPT data on patients treated by psychiatrists were compared with a clinical subset of patients in the National Comorbidity Survey who had been treated in the specialty mental health sector (SMA). RESULTS: Rates of comorbidity were higher in the SMA (53.9%) than in the SPPT (31.5%). The prevalence of schizophrenia diagnoses was more than twice as prevalent in the SPPT as in the SMA sample; anxiety disorders were 2 to 22 times more prevalent in the SMA sample. In the SPPT, 4 of the 10 most prevalent comorbid pairs included schizophrenia or bipolar disorder; only one pair in the SMA sample included either diagnoses. Of the 10 most prevalent comorbidity pairings in the SMA sample, 6 included a phobia diagnosis. CONCLUSIONS: Results of these analyses suggest greater differences in the patterns and rates of comorbidities than one might expect between these 2 samples. Possible reasons for these disparities, including methodological differences in diagnostic ascertainment and underdiagnosis of anxiety disorders, are discussed.

Concomitant pharmacotherapy among youths treated in routine psychiatric practice.

OBJECTIVES: The aim of this study was to assess rates and correlates of concomitant pharmacotherapy in children and adolescents treated by psychiatrists in a broad range of clinical settings. METHODS: Cross-sectional data on 392 child and adolescent patients aged 2-17 years from the 1997 and 1999 American Psychiatric Practice Research Network Study of Psychiatric Patients and Treatments were used, and weighted estimates are provided. RESULTS: Findings indicate that 84% of child and adolescent patients received one or more psychopharmacologic medications; 52% of patients treated with medications received concomitant pharmacotherapy (i.e., two or more medications). Patients who were treated with psychopharmacologic treatments received a median of 2 medications (range, 1-6). Highest rates of concomitant pharmacotherapy were among patients with bipolar disorder (87%). Correlates of concomitant pharmacotherapy included: (1) having a diagnosis of bipolar disorder, (2) having co-occurring Axis I or II disorders or general medical conditions, and (3) currently receiving treatment in an inpatient setting. CONCLUSIONS: Over 40% of child and adolescent patients of psychiatrists were prescribed two or more psychopharmacologic medications. Patients with chronic and clinically complex conditions were more likely to receive concomitant pharmacotherapy. Most often, efficacy of U.S. Food and Drug Administration (FDA)-approved medications has been examined as monotherapy, and cautions on drug interactions and off-label use derived from multiple sources accompany each product. With high rates of concomitant pharmacotherapy among children and adolescents in psychiatric care, additional research on efficacy and safety of this treatment strategy is necessary.

The DSM-IV rates of child and adolescent disorders in Puerto Rico: prevalence, correlates, service use, and the effects of impairment.

BACKGROUND: Few prevalence studies in which DSM-IV criteria were used in children in representative community samples have been reported. We present prevalence data for the child and adolescent population of Puerto Rico and examine the relation of DSM-IV diagnoses to global impairment, demographic correlates, and service use in an island-wide representative sample. METHODS: We sampled 1886 child-caretaker dyads in Puerto Rico by using a multistage sampling design. Children were aged 4 to 17 years. Response rate was 90.1%. Face-to-face interviews of children and their primary caretakers were performed by trained laypersons who administered the Diagnostic Interview Schedule for Children, version IV (DISC-IV) in Spanish. Global impairment was measured by using the Children's Global Assessment Scale scored by the interviewer of the parent. Reports of service use were obtained by using the Service Assessment for Children and Adolescents. RESULTS: Although 19.8% of the sample met DSM-IV criteria without considering impairment, 16.4% of the population had 1 or more of the DSM-IV disorders when a measure of impairment specific to each diagnosis was considered. The overall prevalence was further reduced to 6.9% when a measure of global impairment was added to that definition. The most prevalent disorders were attention-deficit/hyperactivity disorder (8.0%) and oppositional defiant disorder (5.5%). Children in urban settings had higher rates than those in rural regions. Older age was related to higher rates of major depression and social phobia, and younger age was related to higher rates of attention-deficit/hyperactivity disorder. Both overall rates and rates of specific DSM-IV/DISC-IV disorders were related to service use. Children with impairment without diagnosis were more likely to use school services, whereas children with impairment with diagnosis were more likely to use the specialty mental health sector. Of those with both a diagnosis and global impairment, only half received services from any source. CONCLUSIONS: Because we used the DISC-IV to apply DSM-IV criteria, the study yielded prevalence rates that are generally comparable with those found in previous surveys. The inclusion of diagnosis-specific impairment criteria reduced rates slightly. When global impairment criteria were imposed, the rates were reduced by approximately half.

The use of multiple informants in identifying the risk factors of depressive and disruptive disorders--are they interchangeable?

OBJECTIVE: The aim of this study was to asses whether children and their parents identify the same risk factors for disruptive and depressive disorders and to analyze whether combining informant data with a rule that classifies the diagnosis as present if confirmed by at least one informant (OR rule) masks distinctive patterns identified in informant-specific analyses. METHOD: Bivariate logistic regression equations were estimated using the diagnostic classification, based on DISC 2.1, as the outcome variable and informant (parent or child), characteristics of the youth (gender and age), indicators of the context of the interview (site), and family characteristics (income, parental monitoring, and adverse family environment) as predictors. The same predictors were also analyzed with the combined informant (OR rule) as outcome variable. RESULTS: Prevalence of all diagnoses varied with informant. Depressive disorders were more prevalent when the informant was the youth and disruptive disorders when the informant was the parent. The effect of age varied with informant. Odds of being classified as having a DISC disorder increased with age when the informant was the youth but the same effect was not observed when the parent was the informant. When information from parents and youth are combined (with an OR rule) the age effect for disruptive disorders vanishes, and its effect for depressive disorders weakens. CONCLUSIONS: Informants are not interchangeable. Parent- and youth-based estimates of the prevalence of disruptive and depressive disorders were different and showed distinctive age relationships. Combining information from different sources (parents and youths) obscures the apparent effect of age noted in the two informant groups.

Methodological challenges in assessing children's mental health services utilization.

This paper describes the reliability and validity of the service assessment for children and adolescents (SACA) for use among Spanish-speaking respondents. The test-retest reliability of the instrument was assessed in a randomly selected clinical sample of 146 Puerto Rican children and adolescents aged 4-17. Both parents and children were administered the SACA twice by independent interviewers over an average 12-day follow-up period. The accuracy of parental and youth self-reports was assessed by comparing these reports to information obtained from medical records. The results showed that parents and children (aged 11-17) were able to report with fair to moderate reliability any last year use of mental health services, any outpatient mental health services, and school services. Residential and hospitalization services were reported by both informants with substantial test-retest reliability. Slight or no test-retest reliability was obtained for parent and child on the use of the specific type of mental health professionals, as well as parental reports of several treatment modalities. Substantial sensitivity of the SACA was obtained when comparing medical records to parental and child reports to lifetime use of any service and outpatient mental health service. Moderate sensitivity was obtained for last year use of mental health services for both parent and child informants.

Childhood asthma, chronic illness, and psychiatric disorders.

Asthma is a serious and vexing problem for many children and their families. Asthma, like most syndromes, has many symptoms and potential causes and effects. Studies have shown that pediatric asthma is associated with psychiatric disorders, but the specificity and temporality of these relations is not well known. This study examined the associations between any and specific psychiatric disorders and both childhood asthma and other childhood chronic illnesses. The study used the Methods for the Epidemiology of Child and Adolescent Mental Disorders data, a four-site, community-based study of 1,285 pairs of youths and caretakers. Psychiatric disorders were assessed using the Diagnostic Interview Schedule for Children (DISC 2.3). Methods for the Epidemiology of Child and Adolescent Mental Disorders was also used to assess individual characteristics, parental reports of asthma, and other chronic illnesses. Asthma and 'other' chronic illnesses were associated with different psychiatric disorders. In particular, having a history of asthma was associated with having an anxiety disorder, after adjustment for potential confounding, but was not associated with having an affective disorder. Having a chronic illness other than asthma or cancer was associated with having any affective disorder and dysthymia but not anxiety disorder. These results call for more mechanistic research that explores the specific relations between childhood anxiety disorder and asthma and between affective disorder and other pediatric chronic illnesses.

Dimensional measures of psychopathology. The probability of being classified with a psychiatric disorder using empirically derived symptom scales.

OBJECTIVES: We sought to develop a ranking scheme that assigns a probability of having one of four psychiatric disorders to children based on their scores on a symptom scale. We then estimated the impact of each scale symptom on the prevalence of the disorder in the population. METHOD: Logistic regressions were specified for ADHD, ODD, depressive, and conduct disorders using all the individual symptoms in the pertinent scale as predictors. Individual fitted values from the regression function then served as a probability scale measure. We combined the prevalence and influence of each scale symptom to calculate its overall impact on the prevalence of the disorder. RESULTS: Probability distributions had a wide range of values and discriminated between cases and non-cases. Those having a disorder were consistently associated with higher probabilities in the scale. The estimated probability corresponds to the empiric prevalence of the diagnosis in a group of persons sharing the same estimated probabilities. Symptoms varied on their impact on the prevalence of the disorder. CONCLUSIONS: We recommend the estimated probability of the disorder based on the empirically defined scales as dimensional measures that complement prevalence of the disorder. Different symptoms are identified as targets for screening when selection is based on their impact on the prevalence of the disorder than when selection is based on the strength of the association with the disorder. We recommend using a common nosology with different classification schemes; the categorical definition of the disorder, the probability of having the disorder, and the impact of each symptom in the prevalence. Different measures serve different purposes.