Identification of hospitalizations for intentional self-harm when E-codes are incompletely recorded.

CONTEXT: Suicidal behavior has gained attention as an adverse outcome of prescription drug use. Hospitalizations for intentional self-harm, including suicide, can be identified in administrative claims databases using external cause of injury codes (E-codes). However, rates of E-code completeness in US government and commercial claims databases are low due to issues with hospital billing software. OBJECTIVE: To develop an algorithm to identify intentional self-harm hospitalizations using recorded injury and psychiatric diagnosis codes in the absence of E-code reporting. METHODS: We sampled hospitalizations with an injury diagnosis (ICD-9 800-995) from two databases with high rates of E-coding completeness: 1999-2001 British Columbia, Canada data and the 2004 US Nationwide Inpatient Sample. Our gold standard for intentional self-harm was a diagnosis of E950-E958. We constructed algorithms to identify these hospitalizations using information on type of injury and presence of specific psychiatric diagnoses. RESULTS: The algorithm that identified intentional self-harm hospitalizations with high sensitivity and specificity was a diagnosis of poisoning, toxic effects, open wound to elbow, wrist, or forearm, or asphyxiation; plus a diagnosis of depression, mania, personality disorder, psychotic disorder, or adjustment reaction. This had a sensitivity of 63%, specificity of 99% and positive predictive value (PPV) of 86% in the Canadian database. Values in the US data were 74, 98, and 73%. PPV was highest (80%) in patients under 25 and lowest those over 65 (44%). CONCLUSIONS: The proposed algorithm may be useful for researchers attempting to study intentional self-harm in claims databases with incomplete E-code reporting, especially among younger populations.

Impact of drug cost sharing on service use and adverse clinical outcomes in elderly receiving antidepressants.

BACKGROUND: Depression imposes enormous burdens on the elderly. Despite this, rates of initiation of and adherence to recommended pharmacotherapy are frequently low in this population. Although initiatives such as the Medicare Modernization Act (MMA) have improved seniors' access to antidepressants, there are concerns that the patient cost-sharing incorporated in the MMA may have unintended consequences if it reduces essential drug use. Age-related pharmacokinetic and pharmacodynamic changes could make seniors particularly vulnerable to antidepressant regimens used inappropriately to save costs, increasing their risks of morbidity, hospitalizations, and nursing home placements. Two sequential large-scale "natural experiments'' in British Columbia provide a unique opportunity to evaluate the effect of cost sharing on outcomes and mental health service use among seniors. In January 2002 the province introduced a CAD 25 copay (CAD10 for low-income seniors). In May 2003 this copay policy was replaced by a second policy consisting of an income-based deductible, 25% coinsurance once the deductible was met, and full coverage once an out-of-pocket ceiling was met. The transition between the two policies is analogous to what many U.S. seniors experience when they transition from private insurance requiring copays to Medicare Part D requiring deductibles and coinsurance. AIMS: To evaluate whether declines in antidepressant initiation after the introduction of two drug cost-sharing policies in British Columbia were associated with increased use of physician services, hospitalizations, and nursing home admissions among all British Columbia residents aged 65+. METHODS: Records of physician service use, inpatient hospitalizations, and residential care admissions were obtained from administrative databases. Population-level patterns over time were plotted, and effects of implementing the cost-sharing policies examined in segmented linear regression models. RESULTS: Neither policy affected the rates of visits to physicians or psychiatrists for depression, hospitalizations with a depression diagnosis, or long-term care admissions. DISCUSSION: The cost-sharing policies studied may have contained non-essential antidepressant use without substantially increasing mental health service utilization. However, it is possible that the policies had effects that we were unable to detect, such as increasing rates of visits to social workers or psychologists or forcing patients to reduce other spending. Further, the sequential implementation of the policy changes, makes it difficult to estimate the effect of a direct change from full coverage to a coinsurance/income-based deductible policy. IMPLICATIONS FOR HEALTH POLICIES: It may be possible to design policies to contain non-essential antidepressant use without substantially increasing other service utilization or adverse events. However, because undertreatment remains a serious problem among depressed elderly, well-designed prescription drug policies should be coupled with interventions to address under-treatment.

Potential causes of higher mortality in elderly users of conventional and atypical antipsychotic medications.

OBJECTIVES: To investigate the potential mechanisms through which conventional antipsychotic medication (APM) might act, the specific causes of death in elderly patients newly started on conventional APM were compared with those of patients taking atypical APM. DESIGN: Cohort study. SETTING: Community. PARTICIPANTS: All British Columbia residents aged 65 and older who initiated a conventional or atypical APM between 1996 and 2004. MEASUREMENTS: Cox proportional hazards models were used to compare risks of developing a specific cause of death within 180 days of APM initiation. Potential confounders were adjusted for using traditional multivariable, propensity-score, and instrumental-variable adjustments. RESULTS: The study cohort included 12,882 initiators of conventional APM and 24,359 initiators of atypical APM. Of 3,821 total deaths within the first 180 day of use, cardiovascular (CV) deaths accounted for 49% of deaths. Initiators of conventional APM had a significantly higher adjusted risk of all CV death (hazard ratio (HR)=1.23, 95% confidence interval (CI)=1.10-1.36) and out-of-hospital CV death (HR=1.36, 95% CI=1.19-1.56) than initiators of atypical APM. Initiators of conventional APM also had a higher risk of death due to respiratory diseases, nervous system diseases, and other causes. CONCLUSION: These data suggest that greater risk of CV deaths might explain approximately half of the excess mortality in initiators of conventional APM. The risk of death due to respiratory causes was also significantly higher in conventional APM use.

The impact of cost sharing on antidepressant use among older adults in British Columbia.

OBJECTIVE: Antidepressant therapies are underused among older adults and could be further curtailed by patient cost-sharing requirements. The authors studied the effects of two sequential cost-sharing policies in a large, stable population of all British Columbia seniors: change from full prescription coverage to 10-25 dollars copayments (copay) in January 2002 and replacement with income-based deductibles and 25% coinsurance in May 2003. METHODS: PharmaNet data were used to calculate monthly dispensing of antidepressants (in imipramine-equivalent milligrams) among all British Columbia residents age 65 and older beginning January 1997 through December 2005. Monthly rates of starting and stopping antidepressants were calculated. Population-level patterns over time were plotted, and the effects of implementing cost-sharing policies on antidepressant use, initiation, and stopping were examined in segmented linear regression models. RESULTS: Implementation of the copay policy was not associated with significant changes in level of antidepressant dispensing or the rate of dispensing growth. Subsequent implementation of the income-based deductible policy also did not lead to a significant change in dispensing level but led to a significant (p=.02) decrease in the rate of growth of antidepressant dispensing. The copay policy was associated with a significant (p=.01) drop in the frequency of antidepressant initiation among persons with depression. Income-based deductibles reduced the rate of increase in antidepressant initiation over time. Implementation of the copay and income-based deductible policies did not have significant effects on stopping rates. CONCLUSIONS: Introducing new forms of medication cost sharing appears to have the potential to reduce some use and initiation of antidepressant therapy by seniors. The clinical consequences of such reduced use need to be clarified.

Physician follow-up and provider continuity are associated with long-term medication adherence: a study of the dynamics of statin use.

BACKGROUND: Many patients who initiate statin (3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor) therapy discontinue treatment within 1 year. We sought to estimate the rate at which patients reinitiate treatment after long periods of nonadherence and to determine whether reinitiation of treatment is linked to potentially modifiable factors such as physician visits, cholesterol testing, or other encounters with the health care system. METHODS: We studied new users of statins in British Columbia, Canada, who initiated treatment between January 1, 1997, and June 30, 2004, and who had an extended period of nonadherence, defined as at least 90 days after the completion of 1 prescription in which no refill for any statin medication was obtained. Survival analysis was used to estimate the rate of reinitiation of statin therapy. Case-crossover analysis was used to evaluate the predictors of reinitiation. RESULTS: We identified 239 911 new users of statins, of whom 129 167 (53.8%) had a period of nonadherence that lasted for at least 90 days. Of these patients, an estimated 48% restarted treatment within 1 year and 60% restarted treatment within 2 years. Case-crossover analysis revealed events that were associated with a return to adherence, including visits with the physician who initiated the statin regimen (odds ratio [OR], 6.1; 95% confidence interval [CI], 5.9-6.3), a visit with another physician (OR, 2.9; 95% CI, 2.8-3.0), and a cholesterol test (OR, 1.5; 95% CI, 1.4-1.5). Incident myocardial infarction (OR, 12.2; 95% CI, 8.9-16.9) and other cardiovascular disease-related hospitalizations (OR, 3.6; 95% CI, 3.1-4.3) were also strong predictors of reinitiation of treatment. CONCLUSIONS: Physicians should be aware that statin use is dynamic and that many patients have long periods of nonadherence. A follow-up visit with the physician who wrote the initial statin prescription and having a cholesterol test predicted reinitiation of statin therapy. Our results suggest that continuity of care combined with increased follow-up and cholesterol testing could promote long-term adherence by shortening or eliminating long gaps in statin use. This hypothesis should be confirmed in a randomized experiment.

Lipid levels and bone mineral density.

PURPOSE: There has been considerable debate about the potential relationship between the use of statin lipid-lowering drugs and fracture risk; several observational studies suggest a protective effect but no randomized controlled trials have confirmed such a benefit. Because statins are given preferentially to persons with hyperlipidemia, if lipid levels were associated with bone mineral density, this could explain the discrepancy between epidemiological observations and randomized controlled trials. The aim of this study was to examine the relationship between lipid levels and bone mineral density. SUBJECTS AND METHODS: We included the 13592 participants in the National Health and Nutritional Examination Survey (NHANES) III who had bone mineral density and lipid levels measured; participants who reported the use of a lipid-lowering therapy were excluded. We examined the unadjusted bone mineral density across quintiles of total cholesterol, low-density lipoprotein (LDL), and high-density lipoprotein (HDL). We then constructed multivariable models, including age, sex, body mass index, and other potential confounders. RESULTS: In crude analyses, higher total cholesterol and LDL levels were associated with lower bone mineral densities (both P values for trend <.001), whereas higher HDL levels were associated with higher bone mineral densities (P value for trend <.001). However, in fully adjusted models, there was no significant relationship between total cholesterol, LDL, or HDL levels and bone mineral density (all P values for trend >.1). CONCLUSIONS: These results do not support a relationship between lipid levels and bone mineral density.