Battery-Powered Portable Rotary Real-Time Fluorescent qPCR with Low Energy Consumption, Low Cost, and High Throughput

The traditional qPCR instrument is bulky, expensive, and inconvenient to carry, so we report a portable rotary real-time fluorescent PCR (polymerase chain reaction) that completes the PCR amplification of DNA in the field, and the reaction can be observed in real-time. Through the analysis of a target gene, namely pGEM-3Zf (+), the gradient amplification and melting curves are compared to commercial devices. The results confirm the stability of our device. This is the first use of a mechanical rotary structure to achieve gradient amplification curves and melting curves comparable to commercial instruments. The average power consumption of our system is about 7.6 W, which is the lowest energy consumption for real-time fluorescence quantification in shunting PCR and enables the use of our device in the field thanks to its self-contained power supply based on a lithium battery. In addition, all of the equipment costs only about 710 dollars, which is far lower than the cost of a commercial PCR instrument because the control system through mechanical displacement replaces the traditional TEC (thermoelectric cooler) temperature control. Moreover, the equipment has a low technical barrier, which can suit the needs of non-professional settings, with strong repeatability.

Sustainable governance of scarce metals: the case of lithium

Minerals and metals are finite resources, and recent evidence suggests that for many, primary production is becoming more difficult and more expensive. Yet these resources are fundamentally important for society--they support many critical services like infrastructure, telecommunications and energy generation. A continued reliance on minerals and metals as service providers in modern society requires dedicated and concerted governance in relation to production, use, reuse and recycling. Lithium provides a good example to explore possible sustainable governance strategies. Lithium is a geochemically scarce metal (being found in a wide range of natural systems, but in low concentrations that are difficult to extract), yet recent studies suggest increasing future demand, particularly to supply the lithium in lithium-ion batteries, which are used in a wide variety of modern personal and commercial technologies. This paper explores interventions for sustainable governance and handling of lithium for two different supply and demand contexts: Australia as a net lithium producer and Switzerland as a net lithium consumer. It focuses particularly on possible nation-specific issues for sustainable governance in these two countries' contexts, and links these to the global lithium supply chain and demand scenarios. The article concludes that innovative business models, like 'servicizing' the lithium value chain, would hold sustainable governance advantages for both producer and consumer countries.

Effectiveness and medical costs of divalproex versus lithium in the treatment of bipolar disorder: results of a naturalistic clinical trial

OBJECTIVE

The clinical, quality of life (QOL), and medical cost outcomes of treatment with divalproex were compared with lithium in patients with bipolar I disorder over 1 year.

METHODS

In a pragmatic, randomized clinical trial, 201 adults hospitalized with bipolar I manic or mixed episodes were randomized to divalproex or lithium, in addition to usual psychiatric care, and followed for 1 year. All subsequent treatment of bipolar disorder was managed by the patient's psychiatrist. Symptoms of mania and depression were evaluated at baseline and at hospital discharge. Assessments at the start of maintenance therapy and after 1, 3, 6, 9 and 12 months included manic and depressive symptoms, disability days and QOL. Medical resource use data were also collected monthly and costs were estimated using national sources.

RESULTS

Divalproex-treated patients (12%) were less likely to discontinue study medications for lack of efficacy or adverse effects than lithium-treated patients (23%). No statistically significant differences between the treatment groups were observed over the 1-year maintenance phase for clinical symptoms, QOL outcomes, or disability days. Mean estimated total medical costs were USD 28,911 for the divalproex group compared with USD 30,666 for the lithium treatment group. Patients continuing mood stabilizer therapy at 3 months had slightly better health outcomes and substantially lower total medical costs than those who discontinued therapy ( USD 10,091 versus USD 34,432, respectively).

CONCLUSIONS

Divalproex maintenance treatment for bipolar disorder resulted in comparable medical costs, clinical and QOL outcomes compared with lithium. Patients remaining on mood stabilizer therapy had substantially lower total medical costs and better health outcomes compared with those who discontinued therapy.

A rapid and systematic review and economic evaluation of the clinical and cost-effectiveness of newer drugs for treatment of mania associated with bipolar affective disorder

OBJECTIVES

To evaluate the clinical and cost-effectiveness of quetiapine, olanzapine and valproate semisodium in the treatment of mania associated with bipolar disorder.

DATA SOURCES

Electronic databases; industry submissions made to the National Institute for Clinical Excellence.

REVIEW METHODS

Randomised trials and economic evaluations that evaluated the effectiveness of quetiapine, olanzapine or valproate semisodium in the treatment of mania associated with bipolar disorder were selected for inclusion. Data were extracted by one reviewer into a Microsoft Access database and checked for quality and accuracy by a second. The quality of the cost-effectiveness studies was assessed using a checklist updated from that developed by Drummond and colleagues. Relative risk and mean difference data were presented as Forest plots but only pooled where this made sense clinically and statistically. Studies were grouped by drug and, within each drug, by comparator used. Chi-squared tests of heterogeneity were performed for the outcomes if pooling was indicated. A probabilistic model was developed to estimate costs from the perspective of the NHS, and health outcomes in terms of response rate, based on an improvement of at least 50% in a patient's baseline manic symptoms derived from an interview-based mania assessment scale. The model evaluated the cost-effectiveness of the alternative drugs when used as part of treatment for the acute manic episode only.

RESULTS

Eighteen randomised trials met the inclusion criteria. Aspects of three of the quetiapine studies were commercial-in-confidence. The quality of the included trials was limited and overall, key methodological criteria were not met in most trials. Quetiapine, olanzapine and valproate semisodium appear superior to placebo in reducing manic symptoms, but may cause side-effects. There appears to be little difference between these treatments and lithium in terms of effectiveness, but quetiapine is associated with somnolence and weight gain, whereas lithium is associated with tremor. Olanzapine as adjunct therapy to mood stabilisers may be more effective than placebo in reducing mania and improving global health, but it is associated with more dry mouth, somnolence, weight gain, increased appetite, tremor and speech disorder. There was little difference between these treatments and haloperidol in reducing mania, but haloperidol was associated with more extrapyramidal side-effects and negative implications for health-related quality of life. Intramuscular olanzapine and lorazepam were equally effective and safe in one very short (24 hour) trial. Valproate semisodium and carbamazepine were equally effective and safe in one small trial in children. Olanzapine may be more effective than valproate semisodium in reducing mania, but was associated with more dry mouth, increased appetite, oedema, somnolence, speech disorder, Parkinson-like symptoms and weight gain. Valproate semisodium was associated with more nausea than olanzapine. The results from the base-case analysis demonstrate that choice of optimal strategy is dependent on the maximum that the health service is prepared to pay per additional responder. For a figure of less than 7179 British pounds per additional responder, haloperidol is the optimal decision; for a spend in excess of this, it would be olanzapine. Under the most favourable scenario in relation to the costs of responders and non-responders beyond the 3-week period considered in the base-case analysis, the incremental cost-effectiveness ratio of olanzapine is reduced to 1236 British pounds.

CONCLUSIONS

In comparison with placebo, quetiapine, olanzapine and valproate semisodium appear superior in reducing manic symptoms, but all drugs are associated with adverse events. In comparison with lithium, no significant differences were found between the three drugs in terms of effectiveness, and all were associated with adverse events. Several limitations of the cost-effectiveness analysis exist, which inevitably means that the results should be treated with some caution. There remains a need for well-conducted, randomised, double-blind head-to-head comparisons of drugs used in the treatment of mania associated with bipolar disorder and their cost-effectiveness. Participant demographic, diagnostic characteristics, the treatment of mania in children, the use of adjunctive therapy and long-term safety issues in the elderly population, and acute and long-term treatment are also subjects for further study.

How should findings on antisuicidal effects of lithium be integrated into practical treatment decisions?

Beyond its prophylactic efficacy lithium has demonstrated possibly specific antisuicidal effects. Lithium significantly reduces the high excess mortality of patients with affective disorders. Appropriate lithium prophylaxis prevents ca. 250 suicides per year in Germany although lithium salts are prescribed within the National Health Scheme at low frequency (0.06% of the population). Rational treatment strategies most likely would demand for about 10 times higher prescription rates. Guidelines and algorithms for selecting an appropriate prophylactic strategy in affective disorders should take into consideration the suicide risk of an individual patient.

[Prophylactic long-term therapy of affective disorders with lithium, valproic acid and carbamazepine--effectiveness and cost-effectiveness]

Affective disorders have a substantial public health impact due to morbidity, mortality, quality of life impairment and economic implications. There has been renewed debate of the efficacy and effectiveness of Lithium in long-term treatment of affective disorders. In the present paper current literature is discussed with a focus on the routine use of Lithium (effectiveness) and on cost aspects. Recent reviews have confirmed the prophylactic efficacy of Lithium in bipolar affective disorders. However, there is some evidence that effectiveness studies do not hold what efficacy research would promise. Non-compliance is likely to be a major reason for this. Lithium response rates have declined in recent studies. This may be related to diagnostic change (broader concept of affective disorders) and more widespread Lithium use. Non-compliance in patients taking Lithium is a primary factor in relapse with substantial cost effects (due to inpatient care). Current studies compare Lithium with Valproic acid/divalproex, and find cost advantages for the latter possibly due to better compliance. A special suicide-preventive effect has only been proven for Lithium. To ensure the full prophylactic potential of Lithium compliance needs to be improved. Future studies will compare Lithium with Valproic acid/divalproex, Carbamazepine and new treatment strategies more detailed.

Health-economic implications of the onset of action of antimanic agents

BACKGROUND

Three medications, lithium, valproate, and carbamazepine, have been shown to be effective in the treatment of acute mania in randomized, controlled clinical trials. Additional research over the past decade has provided data regarding potential differences between these medications according to their time course of onset and clinical predictors of response in acute mania. These differences have potential impact on both the choice of medication and the health-economics of the treatment of acute mania.

METHOD

Published reports regarding the time course of onset, clinical factors associated with response, and health-economic impact of the treatment of acute mania with lithium, valproate, and carbamazepine were reviewed (PAPERCHASE data base, 1966 to present, terms: bipolar disorder, drug treatment, lithium, valproate, and carbamazepine).

RESULTS

Valproate, when administered via an oral loading dosage, may have a more rapid onset of action than lithium and carbamazepine. Preliminary data suggest that specific clinical factors associated with response differ between the three medications. Health-economic studies suggest that treatment of acute mania with valproate may be associated with greater cost savings due to shorter lengths of hospital stay, particularly in patients with mixed mania and rapid cycling. Patients treated with the combination of carbamazepine and lithium also had reduced hospital lengths-of-stay in one study. Lithium may have greater cost savings in patients with classic mania.

CONCLUSION

Preliminary data from studies reviewed suggest that important differences exist between lithium, valproate, and carbamazepine in their time course of onset and factors associated with response in the treatment of patients with acute mania. These differences may also impact the cost savings associated with treatment with these agents.

Lithium revisited: savings brought about by the use of lithium, 1970-1991

BACKGROUND

Recent estimates of the cost of manic-depressive illness totaled roughly $45 billion in 1991. Using data from the Epidemiological Catchment Area (ECA) study, this study estimates the savings brought about by the use of lithium between 1970 and 1991.

METHODS

Total savings are the difference between estimated actual costs and projected costs had lithium never been introduced. Actual yearly costs were interpolated from data for 1970 and 1991, and projected costs were obtained by adjusting 1970 costs with Consumer Price Index (CPI) and population inflaters. All costs for 1970 were obtained using methods almost identical to those used to calculate the 1991 costs of manic-depressive illness, presented in a previous publication. All savings are presented in 1991 dollars.

RESULTS

Between 1970 and 1991, lithium saved over $170 billion, or roughly over $8 billion per year. Approximately $15 billion in direct costs, which included inpatient and outpatient care as well as research, was saved between 1970 and 1991. The savings are more dramatic for indirect costs, which include the lost productivity of wage-earners, homemakers, family caregivers, and individuals who are in institutions or who committed suicide; these totaled roughly $155 billion.

CONCLUSIONS

Our results suggest that, although manic-depressive illness is still costly, lithium has been tremendously successful in treating the illness, and has provided enormous financial savings in the process.

Effects of divalproex versus lithium on length of hospital stay among patients with bipolar disorder

The medical records of all inpatients with bipolar disorder at the Connecticut Mental Health Center in 1997 were examined to compare length of stay for patients who began monotherapy with divalproex (27 treatment starts) and lithium (20 treatment starts). No statistically significant difference was found in length of stay (11. 5+/-6.9 and 10.3+/-5.2 days for patients on divalproex and lithium, respectively) or other length-of-stay variables. Demographic variables, diagnostic variables, and dosages of neuroleptics and benzodiazepines used adjunctively were similar as well. Dosages and blood levels for divalproex and lithium were consistent with practice guidelines. Prospective randomized studies are needed to compare the cost-effectiveness of divalproex and of lithium in the treatment of bipolar disorder.

[Prophylactic treatment of mood disorders: cost effectiveness analysis comparing lithium and carbamazepine]

Economic impact of lithium therapy has seldom been assessed, economic comparisons with alternative mood stabilizers are almost non existent. This economic evaluation of preventive treatment of mood disorders recurrences (whether unipolar or bipolar) compared lithium with carbamazepine, through data from a randomized controlled clinical trial. A retrospective analysis of medical files of index patients is included in this trial, with experts' global ratings. A brief survey checked for representativity of in-patients length of stay. The model compared two cohorts of patients followed-up for two years after prophylactic treatment had begun. Rates of recurrence and direct medical costs related to mood disorders (prophylactic treatment, treatment of recurrences and serious adverse effects) were assessed. Data extrapolation was necessary because of variable lengths of follow-up during the trial and was based on medical review of index patients. Assessment of consumed health care resources were derived from the available database of the clinical trial, when necessary practice guidelines and experts' opinions were added to the model. Costs were valued according to available french unit costs (Vidal, NGAP, and Comptes de la santé). Analysis only included direct costs. An estimate of mean cost of care of 15,404 French francs per year per patient was calculated. The components of health costs show that in-patient costs are the most important part of annual medical costs for mood disorders (70% of the total costs). Prophylactic medication costs accounted for only 6.9% of total costs. Comparison of prophylactic alternatives gave lithium a clinical benefit with 27% fewer recurrences than carbamazepine. Lithium led to an economic benefit of 4,280 French francs per year of treatment for a single patient. Robustness of this finding was assessed through a sensitivity analysis on estimate of length of stay. Total costs of treatment would be equal between lithium and carbamazepine if length of stay in hospital for lithium patients was increased by 51%. According to the cost-effectiveness analysis developed in this study, lithium should stay the "gold standard" of prophylactic treatment of recurrent mood disorders, and has both clinical and economic advantages compared to carbamazepine.

Pharmacoeconomic and health outcome comparison of lithium and divalproex in a VA geriatric nursing home population: influence of drug-related morbidity on total cost of treatment

OBJECTIVE

Clinicians use mood stabilizers for treating agitation in older patients, but limited information is available regarding side effects and costs in clinical practice. Total costs of treatment were assessed for a subset of geriatric patients receiving either lithium carbonate or divalproex sodium for agitation.

STUDY DESIGN

Retrospective cohort examination of the medical records of 72 patients, 55 years of age or older, in a Veterans Administration long-term, skilled nursing care facility, with a diagnosis of dementia or bipolar affective disorder or both.

PATIENTS AND METHODS

Patients treated with lithium or divalproex during the previous 4 years (1994-1997) were evaluated. Quantitative information was collected and compared regarding routine care, including cost of treatment and laboratory monitoring; and occurrence of adverse events and associated diagnostic and treatment measurements.

RESULTS

Routine care costs for the 2 groups were similar. The lower annual acquisition cost per patient-year for lithium ($15 vs $339 for divalproex) was offset by higher laboratory monitoring costs associated with its administration ($278 vs $53 for divalproex). Examining the adverse events showed that the lithium group had more medication-related adverse events (32 total) than the divalproex group (10 total) and more severe occurrences, including 6 cases requiring medical intensive care unit (MICU) hospitalization. The total mean cost of treating drug-related mild-to-moderate morbidity was $3472 for lithium and $672 for divalproex. An additional cost per admission of $12,910 ($77,462 for all 6 cases) increased total morbidity-related expenditures in the lithium group to $80,934.

CONCLUSIONS

Treating geriatric patients with lithium requires careful monitoring because of side effects. Staffing and resource limitations of a skilled nursing care facility may compromise optimal lithium monitoring in elderly patients. The collected data indicated that divalproex does not result in as many as or as severe adverse events and is, therefore, a safer treatment. The use of lithium was not only more expensive (on average $2875 more per patient) than treatment with divalproex but, more importantly, it was associated with poorer patient outcomes.

The social and economic effects of manic depressive illness and of its treatment in lithium clinics

Advising about the employment of those who have had manic depressive episodes requires Occupational Health Physicians to obtain, with consent, an objective account of previous episodes and to appreciate the enormous range of manic and depressive manifestations. Familiarity is needed with the likely effects of treatment of episodes and the benefits and problems of prophylaxis--not just in general but in individual cases, for example, where driving is required. This article summarizes research into the effects of lithium preparations on the course of the illness, thyroid and renal function and the risk of suicide. The author found that changing from treatment of episodes to continuous prophylaxis benefited employment and personal relationships without causing body weight problems. Many patients do well in life if supported by an experienced professional team, with 61% requiring no further admissions once on lithium, and with an 86% reduction in admissions achieved in our local clinic.

Lithium use and discontinuation in a health maintenance organization

OBJECTIVE

For decades, lithium has been prescribed to treat bipolar disorder. Its efficacy has been documented by clinical trials and by data from specialized clinics. An issue of considerable interest is the use of lithium in managed care systems. This project examined the use of lithium and its continuity of use by enrollees of a health maintenance organization (HMO).

METHOD

In a 6-year longitudinal cohort study, 1,594 lithium users aged 15 years and older who were enrolled in an HMO were followed from 1986-1991. Data were obtained from automated databases and from medical record review of a random 5% subsample of the group (N = 74).

RESULTS

Bipolar disorder was the most frequent morbidity treated. Eighty-four percent (N = 62 or 74) received services from a psychiatrist. Annual prevalence of lithium use increased over the 6-year period from 1.4 to 2.3 persons per thousand HMO members. Duration of use varied widely with some long-term but many short-term users. Discontinuation of treatment was associated with evaluated rates of psychiatric hospitalization and use of psychiatric emergency services. Lithium users were much more likely to receive a variety of other psychotropic drugs than nonusers of the same sex and age.

CONCLUSIONS

Lithium use in this population was more often sporadic than continuous. Discontinuation of lithium was associated with psychiatric hospitalization. If lithium is to be a cost-effective treatment for bipolar disorder, managed care systems will need to improve adherence to drug treatment regimens.

A pharmacoeconomic model of divalproex vs. lithium in the acute and prophylactic treatment of bipolar I disorder

BACKGROUND

Divalproex and lithium are the two most rigorously studied pharmacologic treatments for acute mania in bipolar I disorder in randomized, controlled trials. The differences between the drugs in their time course of onset, predictors of response, and side effects have potentially important pharmacoeconomic implications.

METHOD

Utilizing data from published studies, the University of Cincinnati Mania Project, and a consensus panel of psychiatrists, we developed a decision-analytic model to estimate the costs of treating patients with bipolar I disorder, acutely and prophylactically, for 1 year with divalproex or lithium.

RESULTS

In the overall group of patients with bipolar I disorder, initial treatment with divalproex led to costs that were 9% lower than costs for initial treatment with lithium. Cost savings associated with divalproex were greatest for patients with mixed mania and rapid cycling, whereas cost savings for patients with classic mania were greater for lithium.

CONCLUSION

According to the decision-analytic model developed in this study, divalproex, possibly because of a more rapid rate of antimanic activity associated with oral loading, is a less costly treatment than lithium in the acute and prophylactic treatment of patients with bipolar I disorder over 1 year.

Lithium prophylaxis in recurrent affective illness. Efficacy, effectiveness and efficiency

The efficacy of lithium prophylaxis for recurrent mood disorders is well established. Despite concern that the later efficacy studies have shown poorer results, these studies (after 1980) are equally confirmatory of lithium's efficacy. However, questions have been raised with regards to the effectiveness of lithium prophylaxis under 'ordinary' clinical conditions. Part of the confusion stems from the failure to distinguish clearly efficacy (the potential of a treatment) from effectiveness (the results obtained under clinical conditions). Studies of effectiveness or naturalistic studies show poorer results than efficacy studies in all areas of medicine. The major reason for this discrepancy with lithium prophylaxis is poor compliance. Estimations of the efficiency (cost benefits) of lithium prophylaxis are flawed by the failure to consider such issues. It is proposed that specialised lithium or mood disorders clinics have the potential to narrow the gap between efficacy and effectiveness--efficiency.