Insomnia treatment in New Zealand

Insomnia is defined as having difficulty initiating or maintaining sleep, or non-restorative sleep, together with impaired waking function that has been present for at least one month. These complaints occur despite having adequate time and opportunity for sleep.1,2 Insomnia may occur secondary to other conditions including medical and psychological conditions, substance abuse and other sleep disorders, or it may occur as primary insomnia.Based on a national survey of insomnia symptoms,3,4 we have estimated that 13.0% of New Zealanders aged 20-59 yrs are affected by at least one symptom of insomnia often/always, together with excessive daytime sleepiness. M ori are affected disproportionately (prevalence in the study population: M ori 19.1%, non-M ori 8.9%). The risk of reporting a chronic sleep problem (lasting longer than six months) increased with increasing socioeconomic deprivation and increasing age, but ethnicity and sex were not significant independent risk factors. These figures are similar to international population prevalence estimates, in which approximately 30% of individuals report symptoms of insomnia, 15-20% report insomnia symptoms with daytime impairment and 5-10% meet a diagnosis of insomnia according to standardised criteria.1,2,5A number of health factors such as poor physical health, poor mental health, and symptoms of anxiety or depression are associated with insomnia.6 Individuals with insomnia are more likely to develop symptoms of depression at a later assessment, and persistent insomnia symptoms may increase the likelihood of developing a mental health disorder at a later date.7 It has been shown that insomnia symptoms precede the onset of depression and that depressed older individuals with persistent insomnia are more likely to remain depressed (OR 1.8) than those who do not suffer from insomnia.8,9Few studies have investigated whether there is a causal relationship between insomnia and poor physical wellbeing, however it is known that short sleep duration is a risk factor for increased body mass, metabolic dysfunction, type 2 diabetes and hypertension.10 Individuals with insomnia are more likely to take more medications, use more healthcare resources, be absent from work due to illness more often, and have more work-related and motor vehicle accidents.11,12 Recent studies controlling for anxiety, depression and various medical comorbidities have shown that poor sleep can independently impair health-related quality of life.13Despite significant advancement in pharmacological and non-pharmacological insomnia treatment internationally, including practice parameters for the behavioural and psychological treatment of insomnia,14,15 there is currently no standardised approach to the diagnosis and treatment of insomnia in New Zealand. There is also no formal training of health care professionals working in this area and no current requirement for treatment providers to be legally registered.This study aimed to: Investigate insomnia treatment in New Zealand based on interviews with a snowball sample of different providers; and Estimate the societal costs of insomnia among New Zealanders aged 20-59 yrs. The economic modelling and analysis followed the approach we used in estimating the societal costs of obstructive sleep apnoea syndrome in New Zealand.16Method InterviewStructured interviews of insomnia treatment providers were conducted in person and by telephone between October 2007 and March 2008. The interviews were used to collect information on the profile of patients seen, the diagnostic and treatment practices being used, length of treatment regimes, patient outcomes in terms of treatment success, and the costs of treatment. In addition to open interview questions relating to their diagnosis and treatment practices, interviewees were shown or read a list of treatment options sourced from the literature, but not limited to those validated in the literature.14,15Interviewees were also given the opportunity to comment on any issue pertaining to insomnia treatment that they felt had not been adequately discussed within the structured interview. Initial interviews were conducted with sleep physicians known to the researchers and currently working in established clinics, as well as other health practitioners known to specialise in insomnia treatment. A snowballing method was used during the interview process to build a small database of practitioners to interview that would canvas the range of treatment options currently available. In order to obtain a reasonable representation of the different insomnia treatment practices available in New Zealand, providers were categorised as:specialist physicians (appropriately qualified physician working in specialty medical practice other than general practice ); general practitioners (GP);psychologists; pharmacists; health practitioners (a medically-trained GP or other qualified health practitioner who has taken an interest, or undergone some training, in sleep); and alternative health practitioners (a practitioner with any level of training in alternative medicine, practising insomnia treatment). An equal number of treatment providers were sought from each category for interview. A scoring system for comparing providers was developed based on: category of practitioner; being registered to practise with an appropriate New Zealand Registration Board or Council under the Health Practitioners Competence Assurance Act (2003); apparent knowledge of sleep terminology and medicine (and in particular, insomnia); diagnostic and treatment approaches used; practising within their scope of practice and competency guidelines; and provision of patient follow-up. Knowledge of sleep terminology and sleep medicine was rated against a four-point scale ranging from poor (lacked any knowledge or understanding of sleep terminology or medicine) to excellent (full understanding of sleep terminology and medicine). Economic analysisThis study is a retrospective, prevalence-based, cost utility analysis (CUA) where net treatment costs were compared with quality of life years (QALYs) gained. The impact of treated and untreated insomnia on health resource utilisation and quality of life were evaluated to estimate the total costs of all cases in a one year period. As a one year time frame was used, discounting of costs was not necessary. The interviews and a review of the literature were used to develop a treatment cost decision tree which was used as a basis for the health economic costing model. The decision tree took into account potential pathways for patients with insomnia, the population prevalence of insomnia, and the direct medical and non-medical costs associated with diagnosis of insomnia. To maintain a manageable level of complexity, the final version of the model represented a simplified version of all potential pathways. Pathways with low probability were excluded and the model was limited to one level of on-referral. On-referral pathways were also limited to those identified by the interviewees. Patient pathwaysThe final decision tree is shown in Figure 1. In the first instance, a patient with insomnia could choose to seek treatment or not seek treatment. The treatment provider interviews were used to estimate the total number of patients who would seek treatment, and the proportions who would seek treatment from each category of provider. Since patients cannot self-refer to a specialist physician, this option only occurs in subsequent branches of the model. In each case, the probability of a confirmed diagnosis of insomnia, successful treatment of insomnia, and on-referral to other treatment providers were estimated. For example, we assumed that approximately 40% of patients first approached their GP for treatment of insomnia. Of these, 65% received a diagnosis of insomnia and treatment was initiated. It was estimated that for 87.5% of these patients treatment was successful, with the remaining 12.5% were on-referred to either a psychologist, specialist physician or health practitioner. Similar pathways were constructed for other treatment providers. To account for uncertainty in estimates of the proportion of patients following each pathway, high and low probabilities were calculated as \u00b125% of the base case. Prevalence and QALYsThe prevalence of insomnia was estimated as 13.0%, with a high probability of 16.2% and a low probability of 9.7%. Quality of life years (QALYs) gained with successful treatment were estimated from international literature for the base case values, and 0 was used as the low value.18-20Two treatment providers retrospectively completed a EuroQoL 5D (EQ-5D) questionnaire relating to successful treatment of insomnia in their patients, which were compared against the international literature. The EQ-5D score of one treatment provider was used for the high case value for QALYs gained in the decision tree. The score from the remaining practitioner was determined to be a high outlier and was disregarded. Resource utilisationsAt each node in the decision tree, events take place and resources are consumed. For example, a person with insomnia may consult a pharmacist and be recommended an over-the-counter medication. A purchase is made and transport costs are incurred. The resource utilisation estimates are summarised in Table 1. Table 2. Unit resource cost estimates for insomnia treatment in 2009 New Zealand dollars Resource Base Case Source Direct Medical General practitioner $48.89 Average adult consultation fee21 Specialist physician initial $222.22 Initial adult consultation fee for medical practitioner band III21 Specialist physician follow up $99.56 Follow-up adult consultation fee for medical practitioner band III21 Psychologist $88.89 Initial adult consultation fee21 Health practitioner $120.00 Average adult consultation fee for medical practitioner band II;21 high case, interviews Alternative health practitioner $75.56 Base case and range, interviews Prescription medicine $6.42 Zopiclone,22,23 interviews; base case, 7.5mg @30 days plus prescription dispensing fees24 Non prescription medicine $16.00 Blackmores Valerian Forte,25 interviews Increase in cost per capita for individuals with and without insomnia $627.52 Difference in total health costs of individuals with and without insomnia, derived from population prevalence estimates3,4,26-28 Direct Non-Medical Transport for treatment (round trip) $16.71 Average reimbursement of $0.63/km for round trip to hospital (average 29.83km)29 Sensitivity analysisTo account for uncertainty in prevalence and cost estimates, 10,000 Monte Carlo simulations were conducted using randomly generated variables between the low and high estimates for each model parameter.30 Multiple linear regression was then used to evaluate the effects of each model parameter on the total direct and indirect costs, and the total costs calculated by the model. Results Insomnia treatment providersOf 31 providers approached, 18 agreed to complete an interview. Three specialist physicians, two GPs, one pharmacist, five psychologists, three health practitioners and four alternative health practitioners completed a full interview. Three pharmacists were not able to commit the time required to complete a full interview and agreed to complete a shortened version so that costing information and patient treatment pathways could be determined. Data from all 21 interviews were used in the analyses. Insomnia patients were referred to treatment providers via a number of pathways. Self-referral and GP were the most common modes of referral, with occasional referrals from psychologists, psychiatrists, nurses, occupational health physicians and sleep physicians. Those interviewed reported that insomnia patients have often consulted several other insomnia treatment providers before seeking their services. Among interviewees, 81% stated that their patients had consulted a GP at some stage and 81% stated that their patients had consulted alternative health practitioners in the past. Psychologists, psychiatrists, occupational health physicians and sleep physicians were also occasionally consulted. Four of the 21 interviewees did not hold any registration to practise under the Health Practitioners Competence Assurance Act (2003), three because their field of work is not covered by the Act and one whose registration had lapsed. Providers indicated treating individuals aged 3 months to 90 years for insomnia, of which the majority were middle-aged and Caucasian. The number of patients seen by each practitioner varied greatly, ranging from 15-110 patients per year for specialist physicians to 1000-5200 per year for pharmacists. The majority of interviewees (62%) had poor/fair knowledge of the different types of insomnia. This included all the pharmacists, alternative health practitioners, and GPs interviewed. These providers were also the most likely to confirm a diagnosis of insomnia, were the least likely to use structured interviews, validated questionnaires, or supplementary tools for diagnosis, had the poorest understanding of standard sleep terminology, and offered the most limited range of treatment options. All psychologists and specialist physicians, and the majority of health practitioners, considered supplementary diagnostic tools in their every day practice. Sleep diaries were the most commonly employed adjunct diagnostic tool. Table 3 shows the treatment options offered to insomnia patients by different providers. Sleep hygiene education was the most popular option being offered by 61.9%. Approximately half the providers (52.4%) also considered pharmacological management of insomnia. Specialist physicians, GPs, health practitioners and psychologists always used validated treatment options as per the American Academy of Sleep Medicine guidelines. A quarter of alternative health practitioners used validated treatment options, while the remainder of the interviewees (38%) used forms of treatment lacking any evidence base for successful insomnia treatment. None of the pharmacists interviewed used validated treatment options. Specialist physicians, GPs, and psychologists always implemented treatment according to best practice guidelines, as did three of four alternative health practitioners. However, while health practitioners reported using validated treatment options, two of the three deviated from best practice guidelines for these treatments. Table 3. Treatment options offered to insomnia patients by provider type Treatment options Specialist Physician Pharmacist GP Psychologist Health Practitioner Alternative Health Practitioner N 3 4 2 5 3 4 Pharmacological management 100% 100% 100% 20% 33% 0% Herbal remedies 0% 100%