Studies using Australia's Pharmaceutical Benefits Scheme data for pharmacoepidemiological research: a systematic review of the published literature (1987-2013).

PURPOSE: Research using dispensing claims is used increasingly to study post-market medicines use and outcomes. The purpose of this review is to catalogue more than 25 years of published literature using Australia's Pharmaceutical Benefits Scheme (PBS) dispensing records. METHODS: We searched MEDLINE, PreMEDLINE and Embase and conducted author searches for studies published from 1987 to 2013. Independent reviewers screened abstracts of 3209 articles and reviewed 264 full-text manuscripts. Included studies used PBS dispensing data to measure patterns and/or outcomes of prescribed medicines use or dispensing claims to derive a proxy for a specific disease cohort or health outcome. RESULTS: Of the 228 studies identified, 106 used PBS claims only (56 using claims-level data and 50 using individual-level data) and 63 studies linked individual-level PBS claims to other health data. Most commonly, studies examined trends in drug utilisation (33%), clinician and patient practices (26%), drug use and outcomes (18%) and evaluations of intervention impacts (17%). Sixty-two percent of studies using individual-level data were based on a subset of elderly Australians. Most studies focused on drug classes acting on the nervous system (36%), cardiovascular system (15%) and alimentary tract (11%). Few studies examined prescribed medicines use in children and pregnant women. CONCLUSIONS: Pharmaceutical Benefits Scheme claims represent a significant resource to examine Australia's billion-dollar annual investment in prescribed medicines. The body of research is growing and has increased in complexity over time. Australia has great potential to undertake world-class, whole-of-population pharmacoepidemiological studies. Recent investment in data linkage infrastructure will significantly enhance these opportunities.

Uptake of a web-based oncology protocol system: how do cancer clinicians use eviQ cancer treatments online?

BACKGROUND: The use of computerized systems to support evidence-based practice is commonplace in contemporary medicine. Despite the prolific use of electronic support systems there has been relatively little research on the uptake of web-based systems in the oncology setting. Our objective was to examine the uptake of a web-based oncology protocol system (http://www.eviq.org.au) by Australian cancer clinicians. METHODS: We used web-logfiles and Google Analytics to examine the characteristics of eviQ registrants from October 2009-December 2011 and patterns of use by cancer clinicians during a typical month. RESULTS: As of December 2011, there were 16,037 registrants; 85% of whom were Australian health care professionals. During a typical month 87% of webhits occurred in standard clinical hours (08:00 to 18:00 weekdays). Raw webhits were proportional to the size of clinician groups: nurses (47% of Australian registrants), followed by doctors (20%), and pharmacists (14%). However, pharmacists had up to three times the webhit rate of other clinical groups. Clinicians spent five times longer viewing chemotherapy protocol pages than other content and the protocols viewed reflect the most common cancers: lung, breast and colorectal. CONCLUSIONS: Our results demonstrate eviQ is used by a range of health professionals involved in cancer treatment at the point-of-care. Continued monitoring of electronic decision support systems is vital to understanding how they are used in clinical practice and their impact on processes of care and patient outcomes.

How do medical doctors use a web-based oncology protocol system? A comparison of Australian doctors at different levels of medical training using logfile analysis and an online survey.

BACKGROUND: Electronic decision support is commonplace in medical practice. However, its adoption at the point-of-care is dependent on a range of organisational, patient and clinician-related factors. In particular, level of clinical experience is an important driver of electronic decision support uptake. Our objective was to examine the way in which Australian doctors at different stages of medical training use a web-based oncology system (http://www.eviq.org.au). METHODS: We used logfiles to examine the characteristics of eviQ registrants (2009-2012) and patterns of eviQ use in 2012, according to level of medical training. We also used a web-based survey to evaluate the way doctors at different levels of medical training use the online system and to elicit perceptions of the system's utility in oncology care. RESULTS: Our study cohort comprised 2,549 eviQ registrants who were hospital-based medical doctors across all levels of training. 65% of the cohort used eviQ in 2012, with 25% of interns/residents, 61% of advanced oncology trainees and 47% of speciality-qualified oncologists accessing eviQ in the last 3 months of 2012. The cohort accounted for 445,492 webhits in 2012. On average, advanced trainees used eviQ up to five-times more than other doctors (42.6 webhits/month compared to 22.8 for specialty-qualified doctors and 7.4 webhits/month for interns/residents). Of the 52 survey respondents, 89% accessed eviQ's chemotherapy protocols on a daily or weekly basis in the month prior to the survey. 79% of respondents used eviQ at least weekly to initiate therapy and to support monitoring (29%), altering (35%) or ceasing therapy (19%). Consistent with the logfile analysis, advanced oncology trainees report more frequent eviQ use than doctors at other stages of medical training. CONCLUSIONS: The majority of the Australian oncology workforce are registered on eviQ. The frequency of use directly mirrors the clinical role of doctors and attitudes about the utility of eviQ in decision-making. Evaluations of this kind generate important data for system developers and medical educators to drive improvements in electronic decision support to better meet the needs of clinicians. This end-user focus will optimise the uptake of systems which will translate into improvements in processes of care and patient outcomes.

Hospital discharge diagnostic and procedure codes for upper gastro-intestinal cancer: how accurate are they?

BACKGROUND: Population-level health administrative datasets such as hospital discharge data are used increasingly to evaluate health services and outcomes of care. However information about the accuracy of Australian discharge data in identifying cancer, associated procedures and comorbidity is limited. The Admitted Patients Data Collection (APDC) is a census of inpatient hospital discharges in the state of New South Wales (NSW). Our aim was to assess the accuracy of the APDC in identifying upper gastro-intestinal (upper GI) cancer cases, procedures for associated curative resection and comorbidities at the time of admission compared to data abstracted from medical records (the 'gold standard'). METHODS: We reviewed the medical records of 240 patients with an incident upper GI cancer diagnosis derived from a clinical database in one NSW area health service from July 2006 to June 2007. Extracted case record data was matched to APDC discharge data to determine sensitivity, positive predictive value (PPV) and agreement between the two data sources (κ-coefficient). RESULTS: The accuracy of the APDC diagnostic codes in identifying site-specific incident cancer ranged from 80-95% sensitivity. This was comparable to the accuracy of APDC procedure codes in identifying curative resection for upper GI cancer. PPV ranged from 42-80% for cancer diagnosis and 56-93% for curative surgery. Agreement between the data sources was >0.72 for most cancer diagnoses and curative resections. However, APDC discharge data was less accurate in reporting common comorbidities - for each condition, sensitivity ranged from 9-70%, whilst agreement ranged from κ = 0.64 for diabetes down to κ < 0.01 for gastro-oesophageal reflux disorder. CONCLUSIONS: Identifying incident cases of upper GI cancer and curative resection from hospital administrative data is satisfactory but under-ascertained. Linkage of multiple population-health datasets is advisable to maximise case ascertainment and minimise false-positives. Consideration must be given when utilising hospital discharge data alone for generating comorbidity indices, as disease burden at the time of admission is under-reported.

[Cognitive abnormalities and cannabis use]. / Anormalidades cognitivas no uso da cannabis.

OBJECTIVE: Evidence that cannabis use impairs cognitive function in humans has been accumulating in recent decades. The purpose of this overview is to update knowledge in this area with new findings from the most recent literature. METHOD: Literature searches were conducted using the Web of Science database up to February 2010. The terms searched were: "cannabi*" or "marijuana", and "cogniti*" or "memory" or "attention" or "executive function", and human studies were reviewed preferentially over the animal literature. DISCUSSION: Cannabis use impairs memory, attention, inhibitory control, executive functions and decision making, both during the period of acute intoxication and beyond, persisting for hours, days, weeks or more after the last use of cannabis. Pharmacological challenge studies in humans are elucidating the nature and neural substrates of cognitive changes associated with various cannabinoids. Long-term or heavy cannabis use appears to result in longer-lasting cognitive abnormalities and possibly structural brain alterations. Greater adverse cognitive effects are associated with cannabis use commencing in early adolescence. CONCLUSION: The endogenous cannabinoid system is involved in regulatory neural mechanisms that modulate processes underlying a range of cognitive functions that are impaired by cannabis. Deficits in human users most likely therefore reflect neuroadaptations and altered functioning of the endogenous cannabinoid system.

Delayed preattentional functioning in early psychosis patients with cannabis use.

RATIONALE: Cannabis use is prevalent among the early psychosis (EP) population. The event-related potentials, mismatch negativity (MMN) and P3a are reduced in EP. Cannabinoids have been shown to modulate N-methyl-D-aspartate receptors which are involved in MMN generation. OBJECTIVES: This study is the first to investigate the effects of cannabis use on MMN/P3a in EP. METHODS: EP was defined as a history of psychosis or psychotic symptoms with no progression to date to chronic schizophrenia. Twenty-two EP patients with cannabis use (EP + CANN), 22 non-cannabis-using EP patients (EP-CANN) and 21 healthy controls participated in this study. MMN/P3a was elicited using a two-tone, auditory paradigm with 8% duration deviants. RESULTS: As expected, EP-CANN showed marked reductions in MMN/P3a amplitudes compared to controls. However, EP + CANN showed evidence of a different pattern of neurophysiological expression of MMN/P3a compared to non-using patients, most notably in terms of delayed frontal MMN/P3a latencies. CONCLUSIONS: This study provides further evidence that MMN/P3a deficits are present during early psychosis and suggests that this biomarker may have utility in differentiating substance- from non-substance-related psychoses.

Reflection impulsivity in adolescent cannabis users: a comparison with alcohol-using and non-substance-using adolescents.

RATIONALE: Reflection impulsivity-a failure to gather and evaluate information before making a decision-is a critical component of risk-taking and substance use behaviours, which are highly prevalent during adolescence. OBJECTIVES AND METHODS: The Information Sampling Test was used to assess reflection impulsivity in 175 adolescents (mean age 18.3, range 16.5-20; 55% female)-48 cannabis users (2.3 years use, 10.8 days/month), 65 alcohol users, and 62 non-substance-using controls-recruited from a longitudinal cohort and from the general community and matched for education and IQ. Cannabis and alcohol users were matched on levels of alcohol consumption. RESULTS: Cannabis users sampled to the lowest degree of certainty before making a decision on the task. Group differences remained significant after controlling for relevant substance use and clinical confounds (e.g., anxiety, depressive symptoms, alcohol, and ecstasy use). Poor performance on multiple IST indices was associated with an earlier age of onset of regular cannabis use and greater duration of exposure to cannabis, after controlling for recent use. Alcohol users did not differ from controls on any IST measure. CONCLUSIONS: Exposure to cannabis during adolescence is associated with increased risky and impulsive decision making, with users adopting strategies with higher levels of uncertainty and inefficient utilisation of information. The young cannabis users did show sensitivity to losses, suggesting that greater impulsivity early in their drug using career is more evident when there is a lack of negative consequences. This provides a window of opportunity for intervention before the onset of cannabis dependence.

Chronic cannabis users show altered neurophysiological functioning on Stroop task conflict resolution.

RATIONALE: Chronic cannabis use has been related to deficits in cognition (particularly memory) and the normal functioning of brain structures sensitive to cannabinoids. There is increasing evidence that conflict monitoring and resolution processes (i.e. the ability to detect and respond to change) may be affected. OBJECTIVES: This study examined the ability to inhibit an automatic reading response in order to activate a more difficult naming response (i.e. conflict resolution) in a variant of the discrete trial Stroop colour-naming task. METHODS: Event-related brain potentials to neutral, congruent and incongruent trials were compared between 21 cannabis users (mean 16.4 years of near daily use) in the unintoxicated state and 19 non-using controls. RESULTS: Cannabis users showed increased errors on colour-incongruent trials (e.g. "RED" printed in blue ink) but no performance differences from controls on colour congruent (e.g. "RED" printed in red ink) or neutral trials (e.g. "*****" printed in green ink). Poorer incongruent trial performance was predicted by an earlier age of onset of regular cannabis use. Users showed altered expression of a late sustained potential related to conflict resolution, evident by opposite patterns of activity between trial types at midline and central sites, and altered relationships between neurophysiological and behavioural outcome measures not evident in the control group. CONCLUSIONS: These findings indicate that chronic use of cannabis may impair the brain's ability to respond optimally in the presence of events that require conflict resolution and hold implications for the ability to refrain from substance misuse and/or maintain substance abstention behaviours.

Anormalidades cognitivas no uso da cannabis / Cognitive abnormalities and cannabis use

OBJETIVO: Evidências de que o uso de cannabis prejudica funções cognitivas em humanos têm-se acumulado nas décadas recentes. O propósito desta revisão é o de atualizar o conhecimento nesta área com novos achados a partir da literatura mais recente. MÉTODO: As buscas na literatura foram realizadas utilizando-se o banco de dados Web of Science até fevereiro de 2010. Foram buscados os termos "cannabi*" ou "marijuana" e "cogniti*" ou "memory" ou "attention" ou "executive function", e os estudos em humanos foram revisados preferencialmente em relação aos estudos em animais. DISCUSSÃO: O uso de cannabis prejudica a memória, a atenção, o controle inibitório, as funções executivas e a tomada de decisões, tanto durante como após o período de intoxicação aguda, persistindo por horas, dias, semanas ou mais após o último uso. Os estudos de desafio farmacológico em humanos estão elucidando a natureza e os substratos neurais das alterações cognitivas associadas a vários canabinoides. O uso pesado ou de longo prazo de cannabis parece resultar em anormalidades cognitivas mais duradouras e possivelmente em alterações cerebrais estruturais. Efeitos cognitivos adversos maiores estão associados ao uso de cannabis quando este começa no início da adolescência. CONCLUSÃO: O sistema canabinoide endógeno está envolvido nos mecanismos de regulação neural que modulam os processos subjacentes a uma gama de funções cognitivas que estão prejudicadas pela cannabis. Os déficits em usuários humanos muito provavelmente refletem, portanto, neuroadaptações e o funcionamento alterado do sistema canabinoide endógeno.

OBJECTIVE: Evidence that cannabis use impairs cognitive function in humans has been accumulating in recent decades. The purpose of this overview is to update knowledge in this area with new findings from the most recent literature. METHOD: Literature searches were conducted using the Web of Science database up to February 2010. The terms searched were: "cannabi*" or "marijuana", and "cogniti*" or "memory" or "attention" or "executive function", and human studies were reviewed preferentially over the animal literature. DISCUSSION: Cannabis use impairs memory, attention, inhibitory control, executive functions and decision making, both during the period of acute intoxication and beyond, persisting for hours, days, weeks or more after the last use of cannabis. Pharmacological challenge studies in humans are elucidating the nature and neural substrates of cognitive changes associated with various cannabinoids. Long-term or heavy cannabis use appears to result in longer-lasting cognitive abnormalities and possibly structural brain alterations. Greater adverse cognitive effects are associated with cannabis use commencing in early adolescence. CONCLUSION: The endogenous cannabinoid system is involved in regulatory neural mechanisms that modulate processes underlying a range of cognitive functions that are impaired by cannabis. Deficits in human users most likely therefore reflect neuroadaptations and altered functioning of the endogenous cannabinoid system.