Association between previous and future antipsychotic adherence in patients initiating clozapine: real-world observational study.

BACKGROUND: Although recognised as the most effective antipsychotic for treatment-resistant schizophrenia, clozapine remains underused. One reason is the widespread concern about non-adherence to clozapine because of poor adherence before initiating clozapine. AIMS: To determine if prior poor out-patient adherence to treatmentbefore initiating clozapine predisposes to poor out-patient adherence to clozapine or to any antipsychotics (including clozapine) after its initiation. METHOD: This cohort study included 3228 patients with schizophrenia living in Quebec (Canada) initiating (with a 2-year clearance period) oral clozapine (index date) between 2009 and 2016. Using pharmacy data, out-patient adherence to treatment was measured by the medication possession ratio (MPR), over a 1-year period preceding and following the index date. Five groups of patients were formed based on their prior MPR level (independent variable). Two dependent variables were defined after clozapine initiation (good out-patient adherence to any antipsychotics and to clozapine only). Along with multiple logistic regressions, state sequence analysis was used as a visual representation of antipsychotic-use trajectories over time, before and after clozapine initiation. RESULTS: Although prior poor adherence to antipsychotics was associated with poor adherence after clozapine initiation, the absolute risk of subsequent poor adherence remained low, regardless of previous adherence level. Most patients adhered to their treatment after initiating clozapine (>68% to clozapine and >84% to any antipsychotics). CONCLUSIONS: Despite the fact that poor adherence prior to initiating clozapine is widely recognised by clinicians as a barrier for the prescription of clozapine, the current study supports the initiation of clozapine in all eligible patients.

Antipsychotic utilization trajectories three years after initiating or reinitiating treatment of schizophrenia: A state sequence analysis approach.

OBJECTIVE: This study aims to describe the utilization patterns of antipsychotic (AP) medication in patients with schizophrenia (SCZ), three years after initiating or reinitiating a given AP. METHODS: Based on medico-administrative information on patients living in Quebec (Canada), this retrospective cohort study included 6444 patients with a previous diagnosis of SCZ initiating or reinitiating AP medication between January 1, 2012, and December 31, 2014, with continuous coverage by public drug insurance. For each day of follow-up (1092 days), patient was either exposed to one of the chosen categories of APs, or to none. This patient's sequence of AP exposure overtime has been referred to as the "antipsychotic utilization trajectory". These trajectories were analyzed using a State Sequence Analysis, an innovative approach which provides useful visual information on the continuation and discontinuation patterns of use over time. RESULTS: Clozapine and long-acting injectable second-generation APs had the best continuation and discontinuation patterns over 3 years among all other groups, including less switching of APs, while oral first-generation APs had the poorest patterns. These findings were comparable among incident and non-incident cohorts. Oral second-generation antipsychotics, excluding clozapine, had a poorer continuation and discontinuation pattern than long-acting injectable antipsychotics. CONCLUSION: State Sequence Analysis provides a clear representation of treatment adherence in comparison with dichotomous indicators of adherence or discontinuation. Consequently, this innovative method has shed light on the impact of the AP chosen to initiate or reinitiate treatment in SCZ, which has been identified as a key factor for long-term treatment continuation and discontinuation.

Comparative effectiveness and safety of antipsychotic drugs in patients with schizophrenia initiating or reinitiating treatment: A Real-World Observational Study.

OBJECTIVE: To compare the effectiveness and safety of various second-generation antipsychotics (SGAs), newer oral and long-acting injectable (LAI) SGAs, and first-generation antipsychotics (FGAs) treatments in patients with schizophrenia or schizoaffective disorder (SCZ). METHODS: This retrospective cohort study included medical administrative information for patients with a diagnosis of SCZ living in Quebec (Canada), initiating or reinitiating at least one antipsychotic (AP) drug (with a clearance baseline period of 12 months without any APs). Effectiveness was defined by a reduced risk of hospitalization for mental disorder and discontinuation, and safety by a reduced risk of all-cause death and hospitalization for non-mental disorder, 2 years after AP initiation or reinitiation. Cox proportional hazard models were used to estimate the events associated with different antipsychotics compared with oral olanzapine. RESULTS: The study cohort included 19,615 patients initiating or reinitiating an antipsychotic drug between January 2006 and December 2015. Results showed better effectiveness of clozapine (adjusted HR 0.36, 95% CI 0.30-0.42, p < 0.0001) and LAI SGAs (adjusted HR 0.56, 95% CI 0.51-0.61, p < 0.0001) compared with oral olanzapine when adding discontinuation to hospitalizations for mental disorder as a composite measure of effectiveness, as opposed to oral FGAs (adjusted HR 1.36, 95% CI 1.27-1.46, p < 0.0001) and LAI FGAs (adjusted HR 1.22, 95% CI 1.12-1.32, p < 0.0001). Most APs were as safe as oral olanzapine. CONCLUSION: The effectiveness of LAI SGAs and clozapine appears to justify their use and are as safe as a recognized treatment (oral olanzapine) in Quebec (Canada).

The validity of diagnostic algorithms to identify asthma patients in healthcare administrative databases: a systematic literature review.

Objectives To review the available evidence supporting the validity of algorithms to identify asthma patients in healthcare administrative databases.Methods A systematic literature search was conducted on multiple databases from inception to March 2020 to identify studies that reported the validity of case-finding asthma algorithms applied to healthcare administrative data. Following an initial screening of abstracts, two investigators independently assessed the full text of studies which met the pre-determined eligibility criteria. Data on study population and algorithm characteristics were extracted. A revised version of the Quality Assessment of Diagnostic Accuracy Studies tool was used to evaluate the risk of bias and generalizability of studies.Results: A total of 20 studies met the eligibility criteria. Algorithms which incorporated ≥1 diagnostic code for asthma over a 1-year period appeared to be valid in both adult and pediatric populations (sensitivity ≥ 85%; specificity ≥ 89%; PPV ≥ 70%). The validity was enhanced when: (1) the time frame to capture asthma cases was increased to two years; (2) ≥2 asthma diagnostic codes were considered; and (3) when diagnoses were recorded by a pulmonologist. Algorithms which integrated pharmacy claims data appeared to correctly identify asthma patients; however, the extent to which asthma medications can improve the validity remains unclear. The quality of several studies was high, although disease progression bias and biases related to self-reported data was observed in some studies.ConclusionsHealthcare administrative databases are adequate sources to identify asthma patients. More restrictive definitions based on both asthma diagnoses and asthma medications may enhance validity, although further research is required to confirm this hypothesis.

Healthcare utilization after a first hospitalization for COPD: a new approach of State Sequence Analysis based on the '6W' multidimensional model of care trajectories.

BACKGROUND: Published methods to describe and visualize Care Trajectories (CTs) as patterns of healthcare use are very sparse, often incomplete, and not intuitive for non-experts. Our objectives are to propose a typology of CTs one year after a first hospitalization for Chronic Obstructive Pulmonary Disease (COPD), and describe CT types and compare patients' characteristics for each CT type. METHODS: This is an observational cohort study extracted from Quebec's medico-administrative data of patients aged 40 to 84 years hospitalized for COPD in 2013 (index date). The cohort included patients hospitalized for the first time over a 3-year period before the index date and who survived over the follow-up period. The CTs consisted of sequences of healthcare use (e.g. ED-hospital-home-GP-respiratory therapists, etc.) over a one-year period. The main variable was a CT typology, which was generated by a 'tailored' multidimensional State Sequence Analysis, based on the "6W" model of Care Trajectories. Three dimensions were considered: the care setting ("where"), the reason for consultation ("why"), and the speciality of care providers ("which"). Patients were grouped into specific CT types, which were compared in terms of care use attributes and patients' characteristics using the usual descriptive statistics. RESULTS: The 2581 patients were grouped into five distinct and homogeneous CT types: Type 1 (n = 1351, 52.3%) and Type 2 (n = 748, 29.0%) with low healthcare and moderate healthcare use respectively; Type 3 (n = 216, 8.4%) with high healthcare use, mainly for respiratory reasons, with the highest number of urgent in-hospital days, seen by pulmonologists and respiratory therapists at primary care settings; Type 4 (n = 100, 3.9%) with high healthcare use, mainly cardiovascular, high ED visits, and mostly seen by nurses in community-based primary care; Type 5 (n = 166, 6.4%) with high healthcare use, high ED visits and non-urgent hospitalisations, and with consultations at outpatient clinics and primary care settings, mainly for other reasons than respiratory or cardiovascular. Patients in the 3 highest utilization CT types were older, and had more comorbidities and more severe condition at index hospitalization. CONCLUSIONS: The proposed method allows for a better representation of the sequences of healthcare use in the real world, supporting data-driven decision making.

Care trajectories of individuals with anxiety disorders: A retrospective cohort study.

BACKGROUND: Anxiety disorders (ADs) are associated with increased healthcare use (HCU), and individuals may seek healthcare through various pathways according to clinical and individual characteristics. This study aimed to characterize care trajectories (CTs) of individuals with ADs. METHODS: This is a retrospective cohort study using the Care Trajectories - Enriched Data cohort, a linkage between the Canadian Community Health Surveys (CCHS), and health administrative data from Quebec. The cohort included 5143 respondents reporting ADs to the CCHS between 2009 and 2016. We measured CTs over 5 years before CCHS using a state sequence analysis. RESULTS: The cohort was categorized into five types of CTs. Type 1 (52.7 %) was the lowest care-seeking group, with fewer comorbidities. Type 2 (24.0 %) had higher levels of physical and mental health comorbidities and moderate HCU, mainly ambulatory visits to general practitioners. Type 3 (13.1 %) represented older patients with the highest level of physical illnesses and high HCU, predominantly ambulatory consultation of specialists other than psychiatrists. Types 4 and 5 combined young and middle-aged patients suffering from severe psychological distress. HCU of type 4 (6.7 %) was high, mainly consultations of ambulatory psychiatrists, and HCU of type 5 (3.5 %), was the highest and mostly in acute care. LIMITATIONS: Administrative and survey data may have coding errors, missing data and self-report biases. CONCLUSION: Five types of CTs showed distinct patterns of HCU often modulated by physical and mental health comorbidities, which emphasizes the importance of considering ADs when individuals seek care for other mental health conditions or physical illness.

Multidimensional analysis of adult patients' care trajectories before a first diagnosis of schizophrenia.

For patients at high-risk for developing schizophrenia, a delayed diagnosis could be affected, among many reasons, by their patterns of healthcare use. This study aims to describe and generate a typology of patients' care trajectories (CTs) in the 2 years preceding a first diagnosis of schizophrenia, over a medico-administrative database of 3712 adults with a first diagnosis between April 2014 and March 2015 in Quebec, Canada. This study applied a multidimensional approach of State Sequence Analysis, considering together sequences of patients' diagnoses, care settings and care providers. Five types of distinct CTs have emerged from this data-driven analysis: The type 1, shared by 77.6% of patients, predominantly younger men, shows that this group sought little healthcare, among which 17.5% had no healthcare contact for mental disorders. These individuals might benefit from improved promotion and prevention of mental healthcare at the community level. The types 2, 3 and 4, with higher occurrence of mental disorder diagnoses, represent together 19.5% of the study cohort, mostly middle-aged and women. These CTs, although displaying roughly similar profiles of mental disorders, revealed very dissimilar sequences and levels of care providers encounters, primary and specialized care use, and hospitalizations. Surprisingly, patients of these CTs had few consultations with general practitioners. An increased attentiveness for middle-aged patients and women with high healthcare use for mental disorders could help to reduce delayed diagnosis of schizophrenia. This calls for further consideration of healthcare services for severe mental illness beyond those offered to young adults.

The interactive atlas on health inequalities.

In order to translate specialized scientific information into available, relevant and useful knowledge for decision-makers in public health, the PRIMUS group has developed the on-line Interactive Atlas on Health Inequalities (IAHI), based on user's needs assessments and data availability. Built on multidimensional tables, the IAHI is an health information system which has the power to allow users, especially those concerned by health inequalities, to query rapidly and interactively large volumes of health data (in aggregated format) at different spatial and population levels and to produce meaningful results displayed as tables, graphs or maps almost instantly. Designed explicitly to reveal inequalities in health, the IAHI offers relevant information for understanding social and geographical health inequalities observed for myocardial infarction, osteoporotic fractures, diabetes, chronic pain, schizophrenia, and mood disorders. The IAHI is a powerful support tool for decision-makers, serving the long term goal of closing the gaps across sub-populations, in terms of prevalence of diseases, access to health care, treatments and health outcomes.