Methylphenidate: Gender trends in adult and pediatric populations over a 7year period.

OBJECTIVE: Methylphenidate (MPH) is a prescription-stimulant medication which is authorized in France for two indications: attention-deficit hyperactivity disorder in children (aged≥6years) and narcolepsy in cases where modafinil is ineffective (for children and adults). MPH use has increased worldwide in the past 2 decades in children and adults. Different pharmacoepidemiological Europeans studies have described MPH patterns of use. To our knowledge, few pharmacoepidemiological studies have described MPH patterns of use in France. METHODS: In this context, we have performed a study on regional reimbursement database (PACA-Corse area, covering approximately 4 millions inhabitants). The first part of the study analyzed the evolution of MPH users characteristic's yearly (grouped by age and gender) over a 7year period (2005-2011). In order to better characterize patterns of MPH use in adults, a specific analyze has been performed in the second part on MPH adult users in 2011 with a gender descriptive approach. RESULTS: During the 7year period, MPH dispensing grew from 0.28 to 0.68 patient per 1000. The proportion of adult patients rose from 14.8 to 25.7% (P<0.0001), with patients mainly aged 35-49years old. Gender differences in MPH users were noted between adults and children: the proportion of girls was less important in children than in adult (in 2011, 20.7% of girls among children vs 44.9% among adults). Moreover, the proportion of girls among children increased between 2005 to 2011 (15.1% of girls in 2005 versus 20.7% in 2011). Among adults, women were prescribed more antidepressants (41.5% versus 28.2%, P=0.003) and less opiate maintenance treatments (22.4% versus 31.9%, P=0.03) than men. Finally, 11% of men and 16.4% of women were over 50years old. CONCLUSION: MPH prescription greatly increased over7years, especially in adults. Moreover, in this population, patterns of MPH use differed with gender specificities. Such findings may increase clinical attention on monitoring MPH use in adults.

[Characteristics of subjects under opiate maintenance treatment in primary care using the OPEMA data 2013]. / Caractéristiques des sujets sous traitement de substitution vus en médecine générale d'après l'enquête nationale OPEMA 2013.

AIM: The objective of the study is to describe the characteristics of subjects under opiate maintenance treatment by general practionners (GPs). METHOD: Data analysis from observatory for pharmacodependency in ambulatory medicine survey (observation des pharmacodépendances en médecine ambulatoire [OPEMA]) program in 2013 of the subjects under high dosage buprenorphine (HDB) and methadone prescribed or obtained illegally reported by GPs in France. RESULTS: Survey concerned consumers with 862, 433 and 429 of high dosage buprenorphine and respectively methadone. The average age is 39±9 years respectively, and 36±8 years; over 70% are male; 55% have paid employment and over 30% report social benefits; 9% are in temporary housing. In both groups, more than 50% have anxiety and depression; over 25% have associated somatic disorders and digestive diseases, respiratory, pain is the most common. Almost 99% use oral route; nearly 100% have a daily consumption and about 20% of the alcohol concomitantly; 24% of HDB use benzodiazepines and 18% of the methadone group (P=0.06); 33% of the population using methadone consume illicit psychoactive substances and 21% for HDB population (P<0.0001), in particular cannabis (P<0.0001). Heroin and cocaine are also consumed. CONCLUSION: The population consuming opiate maintenance treatments shows social, somatic and psychiatric vulnerability. Misuse associated forms and consumption of other psychoactive substances and illegal drugs are observed. Despite the complexity of management of these patients, general practitioners have a major role to play.

Night shift decreases cognitive performance of ICU physicians.

BACKGROUND: The relationship between tiredness and the risk of medical errors is now commonly accepted. The main objective of this study was to assess the impact of an intensive care unit (ICU) night shift on the cognitive performance of a group of intensivists. The influence of professional experience and the amount of sleep on cognitive performance was also investigated. METHODS: A total of 51 intensivists from three ICUs (24 seniors and 27 residents) were included. The study participants were evaluated after a night of rest and after a night shift according to a randomized order. Four cognitive skills were tested according to the Wechsler Adult Intelligence Scale and the Wisconsin Card Sorting Test. RESULTS: All cognitive abilities worsened after a night shift: working memory capacity (11.3 ± 0.3 vs. 9.4 ± 0.3; p < 0.001), speed of processing information (13.5 ± 0.4 vs. 10.9 ± 0.3; p < 0.001), perceptual reasoning (10.6 ± 0.3 vs. 9.3 ± 0.3; p < 0.002), and cognitive flexibility (41.2 ± 1.2 vs. 44.2 ± 1.3; p = 0.063). There was no significant difference in terms of level of cognitive impairment between the residents and ICU physicians. Only cognitive flexibility appeared to be restored after 2 h of sleep. The other three cognitive skills were altered, regardless of the amount of sleep during the night shift. CONCLUSIONS: The cognitive abilities of intensivists were significantly altered following a night shift in the ICU, regardless of either the amount of professional experience or the duration of sleep during the shift. The consequences for patients' safety and physicians' health should be further evaluated.

Patterns of Methylphenidate Use and Assessment of Its Abuse among the General Population and Individuals with Drug Dependence.

PURPOSE: The aim of this study was to describe the extent of methylphenidate (MPH) abuse and characterize its patterns by following several cases involving intravenous administration of crushed MPH tablets. METHODS: First, a drug reimbursement database (covering 4 million inhabitants) was explored to assess the magnitude of MPH abuse among the general population, and second, a specific study based on individuals with drug dependence was performed to describe abusers' characteristics (n = 64), patterns of abuse and clinical implications. RESULTS: From 2005 to 2011, the number of patients who were dispensed MPH at least once increased by 166%. The patients with 'deviant' patterns of MPH consumption were mainly male adults with opiate maintenance treatment reimbursements. MPH abusers had precarious living conditions. Half of them consumed MPH daily by intravenous route and reported amphetamine-like effects (cardiovascular events, weight loss, psychiatric adverse events). CONCLUSION: Given the increase of MPH use, it is important to warn the scientific community about possible MPH abuse, especially in individuals with drug dependence. This study has facilitated public health intervention and dissemination of information related to MPH abuse among health care professionals at local and national levels.

Use of a multi-state model in a claims database: illustration with methadone.

PURPOSE: In pharmacoepidemiology, one of the main concerns is analysis of drug exposure time. However, in real-life settings, patient's behavior is complex and characterized by drug exposure dynamics. Multi-state models allow assessing the probabilities of various patterns, instead of just continuous use and/or discontinuation. The aim of this study was to illustrate with methadone, the use of multi-state model (MSM) in a large claims database. METHODS: This study is based on the French health insurance reimbursement database. Methadone exposure is defined using four states for each period of follow-up: syrup only, capsule only, syrup-capsule and no dispensing. The model considered 12 possible transitions (including reverse transitions) from one state to another. To describe these transitions a time-homogeneous Markov model was used. RESULTS: A total of 1265 methadone users were included. When patients belonged to the syrup-capsule state, they had a 61.8% chance of moving to capsules the following month and 20.9% of moving to syrup. The probability of moving from the syrup to the non-user state was 13.6% (11.7% from capsule state to non-user state). The average length of stay was 5.9 months (CI95%: [5.5-6.4]) in capsule state, 4.9 (CI95%: [4.6-5.2]) in syrup state and 5.9 (CI95%: [5.5-6.3]) in non user state. CONCLUSION: MSM provided a good description of methadone patterns of use. It outlined behaviors which have led to a rapid spread of capsule formulation among methadone users. Therefore, it illustrates the utility of MSM for modeling multiple sequences of drug use in a large claims database.

New methadone formulation in France: results from 5 years of utilization.

BACKGROUND: In France, methadone has historically been less accessible than buprenorphine. In 2008, a dry formulation (capsule) was introduced into the market, aimed in particular to improve methadone accessibility. OBJECTIVE: To describe the impact (prevalence of use, patient profiles and compliance with requirements) of the dry methadone formulation in France. METHOD: A retrospective cohort (from 2008 to 2012) was created from the data of the French General Health Insurance System which covers 80% of the French population. For each years, all subjects affiliated to this insurance system in southeast France (about 8.5 million inhabitants) with at least two reimbursements of methadone between 1st January and 31st December were selected. RESULTS: In 2012, the proportion of capsule users was almost the same as that of syrup users (40.0% versus 43.1%; p < 0.001). The rise in the number of methadone users has followed the rise in capsule users. Over the study period, the proportion of patients using benzodiazepines or antidepressants was 6-9% (p < 0.001) higher for capsule users than for syrup users. On average over the study period, 18% of subjects had at least one concurrent issue of the two forms. CONCLUSION: The study has shown the rapid spread of the capsule formulation among methadone users. This may suggest that the capsule is well accepted by patients and the medical community. However, the monitoring of methadone-related deaths should continue because of the pharmacodynamic properties of methadone and the context of relaxed regulations concerning access to methadone maintenance treatement (MMT).

Maternal factors influencing the decision to breastfeed newborns conceived with IVF.

OBJECTIVES: The breastfeeding initiation rate is extremely disparate worldwide and remains low in France, with a breastfeeding initiation rate of 60.2%. Some studies have reported increased early parenting difficulties in women who conceived with in vitro fertilization (IVF). Our study had two main objectives: (1) to determine by a retrospective chart review the demographic and medical factors associated with breastfeeding versus formula feeding in women who had undergone IVF and (2) to assess by survey study the reasons for the infant feeding decision (breastfeeding versus formula feeding) for women who conceived by IVF. SUBJECTS AND METHODS: By telephone interviews, we conducted a longitudinal nonexperimental cohort study of French women who had a live birth after IVF. Fertility data and obstetric outcomes were collected from individual medical records. RESULTS: Among women who had a live birth after IVF (n=73), 63% (n=46) initiated breastfeeding for a mean duration of 6.2±6.2 months. In our IVF population, the breastfeeding initiation rate was similar to that in the general French population. The following three factors were found to have a significant negative influence on breastfeeding initiation: duration of infertility greater than 2 years, cesarean delivery, and history of formula feeding when the women themselves were newborns. CONCLUSIONS: Long duration of infertility and history of cesarean delivery after IVF negatively influenced the breastfeeding initiation rate. For this subgroup of patients, postpartum care should be enhanced to support the early mother-baby relationship and promote breastfeeding.

[Antipsychotic use in the cohort PACA-Alz in patients with Alzheimer's disease and other dementia in 2010]. / Consommation d'antipsychotiques chez les sujets atteints de maladie d'Alzheimer et maladies apparentées de la cohorte PACA-Alz 2010.

AIM: The aim of the study was to identify and to characterize patients with Alzheimer's disease or related dementia describing antipsychotics and other psychotropic expositions. METHODS: The study was performed, in 2010, based on Provence-Alpes-Côte d'Azur region (PACA)-Corse Alz cohort included patients with dementia, with chronic condition 'Alzheimer disease or related disease' and/or had at least one delivery of Alzheimer's specific treatment, registered in the General Health Care System. Psychotropic drugs were extracted according anatomical, therapeutical and chemical code. Chronic exposure defined as more than 3 consecutive deliveries. RESULTS: Among 34 696 included patients, 26.9% were men and 68.8% were 80 years old and more. Among them, 26% received at least one antipsychotic medication, with a chronic exposition estimated around 61.3%. Antidepressant and anxiolytic were consumed respectively by 47% and 45.3% of patients. Risperidone was the most used antipsychotic (11.2%). The Health care use (hospitalizations, nurses and physicians visits) was significantly higher among patients with antipsychotics. CONCLUSION: Antipsychotics use in patients with dementia remains high. The follow up of this regional cohort would be helpful to identify the impact of guidelines on the prescription and the care of patients with dementia.

[Use of generic high dose buprenorphine (HDB): about a qualitative survey]. / Utilisation des génériques de la buprénorphine haut dosage (BHD) : évaluation qualitative.

OBJECTIVE: Analyze the factors of the low use of buprenorphine (HDB) generic in France, studying heath care professionals' and patients' attitudes towards this substitution. METHODS: A qualitative method based on the realization of semi-directive conversations was held. 14 health care professionals and 10 patients were interviewed. RESULTS: Generic drug of HDB presents undeniable economic benefits and galenic advantages. Physicians suggest this generic at first prescription or with stabilized patients. The switch princeps/generic is more difficult with patients who diverted the product, or when they are accustomed to the brand product. Some patients prefer brand product because of its galenics, or of the perception of greater efficiency. CONCLUSION: There is a certain distrust compared to this generic. It is necessary to properly support the prescription of this drug in order to help health care professionals and patients (therapeutic education, medical information, creating a climate of trust).

OPPIDUM surveillance program: 20 years of information on drug abuse in France.

It is important to assess drug abuse liability in 'real life' using different surveillance systems. Some are based on specific population surveys, such as individuals with drug abuse or dependence, or under opiate maintenance treatment, because this population is very familiar with drugs and is more likely to divert or abuse them. In France, an original surveillance system based on this specific population and called 'Observation of illegal drugs and misuse of psychotropic medications (OPPIDUM) survey' was set up in 1990 as the first of its kind. The aim of this article is to describe this precursor of French drug abuse surveillance using different examples, to demonstrate its ability to effectively give health authorities and physicians interesting data on drug abuse. OPPIDUM is an annual, cross-sectional survey that anonymously collects information on abuse and dependence observed in patients recruited in specialized care centers dedicated to drug dependence. From 1990 to 2010, a total of 50,734 patients were included with descriptions of 102,631 psychoactive substance consumptions. These data have outlined emergent behaviors such as the misuse of buprenorphine by intravenous or nasal administration. It has contributed to assess abuse liability of emergent drugs such as clonazepam or methylphenidate. This surveillance system was also able to detect the decrease of flunitrazepam abuse following implementation of regulatory measures. OPPIDUM's twenty years of experience clearly demonstrate that collection of valid and useful data on drug abuse is possible and can provide helpful information for physicians and health authorities.

Doctor shopping reveals geographical variations in opioid abuse.

BACKGROUND: Prescription opioid abuse is not homogeneous due to varying patterns of use and different geographic preferences. Because doctor shopping is one of the main sources of diversion, it has previously been used to estimate drug abuse. OBJECTIVES: The aim of this study was to describe and compare opioid abuse in 2008 using doctor shopping to estimate abuse in 3 French regions. SETTING: Data for this study came from the General Health Insurance (GHI) reimbursement database, which covers 77% of the French population. All individuals living in Provence-Alpes-Cote d'Azur-Corse (PACA), Rhone-Alpes (RA), or Midi-Pyrenees (MP) that received at least one reimbursement for oral opioids from the GHI in 2008 were included. METHODS: Oral opioids under study were opioids for mild to moderate pain (dextropropoxyphene, codeine, tramadol, dihydrocodeine), opoids for moderately severe to severe pain (oral morphine, oxycodone, buprenorphine painkiller, hydromorphone), and opioid maintenance treatments (buprenorphine maintenance, methadone). For a given opioid, the Doctor Shopping Quantity (DSQ) is the quantity obtained by overlapping prescriptions from several prescribers. It is used to estimate the magnitude of abuse. The Doctor Shopping Indicator (DSI) is the DSQ divided by the total dispensed quantity. It is used to estimate the abuse corrected for use. RESULTS: The total DSQ for opioids in PACA (213.3 DDD/1,000 inhabitants) was twofold superior to that in RA (115.1 DDD/1,000) and in MP (106.2 DDD/1,000). The DSQ of opioids for mild to moderate pain was 75.5DDD/1000 (DSI=1.1%), 19.7DDD/1,000 (DSI=5.0%) for opioids for moderately severe to severe pain, and 55.3DDD/1,000 (DSI=6.2%) for opioid maintenance treatments. Emergent signals of abuse have been observed at a regional level for oxycodone in MP and dihydrocodeine in RA and MP. LIMITATIONS: The main limitation of this study is that the GHI reimbursement database provides information about dispensed and reimbursed prescription drugs, and not necessarily the actual quantity used. CONCLUSION: These results confirm important variations in the 3 French regions despite them being geographically close. Besides, they highlight different rates of opioid abuse between opioids for mild to moderate pain, opioids for moderately severe to severe pain, and opioid maintenance treatments, as well as differences within these groups.

[Harm reduction centers ("CAARUD"): privileged places for warning signal detection in addictovigilance]. / Les CAARUD, lieux privilégiés d'émergence de signaux pour l'addictovigilance.

This study aims to describe profile and consumptions of subjects suffering a substance use disorder recruited in harm reduction centers (HRC, French "CAARUD", 156 included subjects in 7 centers) for the 2010 OPPIDUM survey, performed by the French CEIP-Addictovigilance network, in order to compare them to subjects included in ambulatory care centers (ACC, French "CSAPA", 3549 subjects included in 80 centers). Subjects recruited in HRC are younger and more precarious; they consume more illicit drugs, and prescription drugs known to be diverted (methylphenidate, morphine, ketamine,…). They consume less opiate maintenance treatment, antidepressants and psychotics. Obtaining and consumption modalities are also different (more illegal acquisitions for prescription drugs, more intravenous route use and less nasal route use in HRC). HRC are privileged places for watching substance use disorder (abuse, dependence) or prescription drugs diversions, and for early warning signal detection in addictovigilance.

[General Practitioners' Contribution to Dependence Assessment: the OPEMA Programme]. / Observation des pharmacodépendances en médecine ambulatoire : le programme OPEMA.

Aim. This study presents the OPEMA (Observation des pharmacodépendances en médecine ambulatoire) programme and the main results of its last annual survey (november 2010). Method. Collected data concern mainly subjects' sociodemographic situation, their state of health and their current consumption of psychoactive substance. Results. In 2010, 1394 subjects have been included, describing 2 450 consumptions of psychoactive susbtance. Their mean age is 38,2±12,7 years. Eighty-six per cent have a stable accomodation and 52% are in employment. Fifty-six percent of included subjects present a psychiatric comorbidity. Among included subjects, HIV and HVC prevalence is respectively 3% and 20%. Fourty-five percent of included subjects have been using intraveinous route, 6% of whom using it currently. Eighty-two percent consume opiate maintenance treatment and 29% benzodiazepines. Conclusion. The OPEMA programme supplement the french pharmacodependence assessment system with collecting data from general practitioners, and promotes a global knowledge of dependent subjects' state of health.

Which psychoactive prescription drugs are illegally obtained and through which ways of acquisition? About OPPIDUM survey.

The objective of the study was to determine which psychoactive prescription drugs are illegally obtained and through which ways of acquisition. OPPIDUM is an annual national study. It is based on specialized care centers that included subjects presenting a drug dependency or under opiate maintenance treatment. All their psychoactive substances consumed are reported. This work focuses on the different ways of acquisition specially the illegal ways of acquisition (bought on the street, forged prescription, stolen, given, internet). For each medication illegally obtained, a ratio has been calculated (number of illegal acquisitions divided by the number of described acquisitions). In 2008, 5542 subjects have been included and have described the consumption of 11 027 substances including 63.8% of prescription drugs. Among them, 11% were illegally obtained. The different illegal acquisition ways were 'street market' (77.6%), 'gift' (16.6%), 'theft' (2.3%), 'forged prescription' (2.3%), and 'internet' (0.7%). The third first drugs illegally obtained were high dosage buprenorphine, methadone, and clonazepam. Some prescription drugs, less consumed, have an important ratio of illegal acquisition like ketamine, flunitrazepam, morphine, trihexyphenidyl, or methylphenidate. This study confirms that theft, forged prescription and internet are few used and permits to highlight diversion of prescription drugs. It is important to inform healthcare professionals on the different prescription drugs that are illegally obtained.

Misuse of buprenorphine maintenance treatment since introduction of its generic forms: OPPIDUM survey.

PURPOSE: The purpose of the study was to compare, using data from Observation of Illicit Psychotropic Substances or Non-medical Used Medications (OPPIDUM) surveys, first, the profile of buprenorphine users and their modalities of buprenorphine use from 2006 to 2008 and, second, two subgroups: brand-name and generic buprenorphine users in 2008. METHODS: OPPIDUM is an annual, nationwide, multicentric, cross-sectional survey, including buprenorphine users followed in specialised centres dedicated to drug dependence. The evolution of the profile during three consecutive years (2006, 2007 and 2008) was analysed using Cochran-Armitage test for trend. A multivariate regression analysis was used to identify the factors associated with the use of generic compared with brand-name buprenorphine in 2008. RESULTS: In OPPIDUM, 1311 individuals used buprenorphine in 2006, 1688 in 2007 and 1696 in 2008. The proportion of users of generic buprenorphine increased from 4.2% in 2006 to 31.7% in 2008. From 2006 to 2008, a decrease in intravenous use and higher than recommended dosage, with an increase in occupation, have been observed. According to the multivariate analysis, factors associated with being generic buprenorphine user compared with brand-name buprenorphine user in 2008 were younger age, more education, absence of use of alcohol with buprenorphine, absence of heroin and/or cocaine use and absence of nasal route for buprenorphine. CONCLUSION: Three years after the launch of the buprenorphine generic, the health professionals' and buprenorphine users' perception of generic can still change. Additionally, the long-term impact of generic medications with abuse potential has not yet been studied. Thus, continued monitoring of buprenorphine is needed.

Assessment of abuse of tianeptine from a reimbursement database using 'doctor-shopping' as an indicator.

Doctor-shopping is a patient behaviour characterized by simultaneous consultations of several physicians during the same period. Some case reports have described an abuse of tianeptine, an atypical antidepressant. Our objective was to assess the extent of abuse of this drug with a method quantifying doctor-shopping in comparison with other antidepressants and benzodiazepines (BZD). All dispensations of antidepressants and BZD during the year 2005 in a French area of 4.5 million inhabitants were extracted from a reimbursement database. For each patient, two quantities were computed: quantity dispensed and obtained by doctor-shopping. Tianeptine and other drugs were compared using their doctor-shopping indicator (DSI), defined as the percentage of drug obtained by doctor-shopping among dispensed quantity; 410 525 patients received at least one antidepressant dispensation during the year 2005. Tianeptine was the sixth most dispensed antidepressant. The DSI of tianeptine was 2.0%, ranking it first among antidepressant (the second being mianserine with a DSI of 1%). Flunitrazepam has the highest DSI (30.2%), the DSI of the five following BZD (clonazepam, zolpidem, oxazepam, diazepam, bromazepam) range from 3.0% to 2.0%. Tianeptine is associated with higher DSI, compared with other antidepressants, suggesting that it may be subject to abuse in the population. Moreover, its DSI as a measure of diversion is similar to the DSI of diazepam or bromazepam.

[Post-marketing surveillance systems for psychoactive prescription drug abuse]. / Les systèmes d'évaluation de l'abus et de la dépendance des médicaments psychoactifs.

Drugs affecting the central nervous system form a unique group of products for surveillance because they could be misused, abused or diverted. Considering the characteristics of this behaviour that is often concealed, specific post-marketing surveillance systems have been developed to monitor abuse of prescription drugs in some countries. The purpose of this review is to list and to describe post-marketing surveillance systems, according their methodology, in France and in foreign countries. These programs are based on adverse effect notifications, medical or legal consequences of abuse, general or specific population-based survey, professional networks or medication databases. Some programs use simultaneously several information sources. In conclusion, the multifaceted nature, the diversity and the inventiveness of post-marketing surveillance systems reflects the complexity of the abuse issue.

Monitoring of benzodiazepine diversion using a multi-indicator approach.

Fourteen benzodiazepine (BZD) or BZD-like medications were analyzed with three data sources aiming to assess prescription drug abuse for the year 2008. After a descriptive analysis, a principal component analysis was carried out to explore correlations between seven indicators obtained by different methods using these three different data sources and to compute a composite score of diversion for these drugs. For all the indicators, flunitrazepam appears first with much higher values than the other drugs, whereas clonazepam appears in the second or third place. These methods produce globally correlated indicators and the composite score obtained from principal component analysis ranks the drugs with the highest diversion as follows: flunitrazepam, clonazepam, oxazepam, diazepam, and bromazepam. This study shows that these methods yield consistent results. Their integration into a single multi-indicator approach gives health authorities a global view of different behaviors regarding diversion of a given drug.

Evolution of opioids reimbursement since 2004 from the National Database of the General Health Insurance System.

OBJECTIVE: This study aims at evaluating trends in the consumption of opioids over the last years to assess the impact of public health measures on the management of pain and opiate addiction in France. METHODS: The evolution of opioids consumption was analysed by using the national database of the General Health Insurance System in France between 2004 and 2008. RESULTS: During the study period, the reimbursed quantities of opioids used for pain management have increased by 13%, except for dextropropoxyphene that has decreased by 9%. The reimbursed quantities of opioids used for substitution maintenance treatments for opioid dependence have increased by 34%, with a 116% increase for methadone. CONCLUSION: This study suggests that consumption of opioids is globally increasing in France and reveals discrepancies concerning the evolution of the different drugs. It allows to analyse switches of consumption between different opioids and constitutes the first step for further studies targetting signals of diversion and abuse.

Patterns of methylphenidate use and assessment of its abuse and diversion in two French administrative areas using a proxy of deviant behaviour determined from a reimbursement database: main trends from 2005 to 2008.

BACKGROUND: Methylphenidate is a psychostimulant drug indicated for the treatment of attention-deficit hyperactivity disorder (ADHD). Its abuse and diversion have been previously described in specific populations, such as students; however, few studies investigating abuse and diversion among the overall population are available. OBJECTIVES: The aim of this study was to describe patterns of methylphenidate use and to explore the magnitude of its abuse and diversion in two French administrative areas using data from a reimbursement database. A proxy of 'deviant behaviour' was used for the abuse and diversion of methylphenidate, defined using the following parameters: total number of defined daily doses (DDDs) of methylphenidate dispensed; number of different pharmacies seen for dispensing of methylphenidate; number of prescribers consulted for a prescription of methylphenidate; and number of dispensings of methylphenidate. Data from the reimbursement database were analysed by clustering methods. These data were assessed from 2005 to 2008. METHOD: The French General Health Insurance System (GHIS) database was used to obtain data on methylphenidate use in two French administrative areas. Individuals affiliated to the GHIS who had a prescription for methylphenidate reimbursed between 1 January and 31 March of 4 selected years (2005, 2006, 2007 and 2008) were included. After the first dispensing of methylphenidate for these individuals, all their dispensings (including methylphenidate and other psychoactive drugs) were monitored over a 9-month period. Following a descriptive analysis, a clustering method was used to identify different subgroups of subjects according to the methylphenidate consumer profile characteristics. RESULTS: With regard to the number of patients who had a dispensing for methylphenidate during the first quarter of the year, an 84% increase was observed between 2005 (n = 640) and 2008 (n = 1175). The clustering method identified two subgroups. One of them was characterized by a higher number of dispensings, different prescribers and pharmacies and a greater total dispensed quantity, suggesting a deviant behaviour and, thus, possible abuse and diversion of methylphenidate. These subjects were older (aged 35.4 ± 11.3 years) and were more frequently patients receiving benzodiazepines, antidepressants, antipsychotics and maintenance opioid treatment. The proportion of subjects with a deviant behaviour increased from 0.5% in 2005 to 2% in 2007 and then decreased to 1.2% in 2008. CONCLUSION: This method was able to assess the magnitude of methylphenidate abuse liability and to follow its evolution. The decrease in methylphenidate abuse and diversion seen between 2007 and 2008 can be explained by the enactment in April 2008 of specific regulations for prescription drugs (such as methylphenidate) that are deemed by the French government to have the potential for misuse; these regulations require the establishment of a 'contract of care' between the GHIS, prescriber and patient.