Capturing what matters: updating NICE methods guidance on measuring and valuing health

In July 2019, the National Institute for Health and Care Excellence (NICE) initiated a major review of its health technology evaluation methods to update its methods guide. This update has recently concluded with the publication of its health technology evaluation manual in January 2022. This paper reports the methods and findings of the review in relation to the recommended approach to use for the measurement and valuation of health-related quality of life (HRQoL) in submissions to NICE. Issues related to (i) the methods to use when NICE’s preferred measure (EQ-5D) is not appropriate or not available; (ii) adjusting health state utility values over time to account for age; (iii) measuring and valuing HRQoL in children and young people; and (iv) including carers’ QoL in economic evaluations were included in this review. This commentary summarises the methods used to undertake the review, its findings, and the changes to NICE methods that were proposed based on these findings. It also outlines topics where further research is needed before definitive methods guidance can be issued. The broad proposals described here were subject to a public consultation in 2020 and a further consultation on the updated methods guidance was completed in October 2021 before the publication of the manual in January 2022.

A structured review of health utility measures and elicitation in advanced/metastatic breast cancer

BACKGROUND

Health utilities are increasingly incorporated in health economic evaluations. Different elicitation methods, direct and indirect, have been established in the past. This study examined the evidence on health utility elicitation previously reported in advanced/metastatic breast cancer and aimed to link these results to requirements of reimbursement bodies.

METHODS

Searches were conducted using a detailed search strategy across several electronic databases (MEDLINE, EMBASE, Cochrane Library, and EconLit databases), online sources (Cost-effectiveness Analysis Registry and the Health Economics Research Center), and web sites of health technology assessment (HTA) bodies. Publications were selected based on the search strategy and the overall study objectives.

RESULTS

A total of 768 publications were identified in the searches, and 26 publications, comprising 18 journal articles and eight submissions to HTA bodies, were included in the evidence review. Most journal articles derived utilities from the European Quality of Life Five-Dimensions questionnaire (EQ-5D). Other utility measures, such as the direct methods standard gamble (SG), time trade-off (TTO), and visual analog scale (VAS), were less frequently used. Several studies described mapping algorithms to generate utilities from disease-specific health-related quality of life (HRQOL) instruments such as European Organization for Research and Treatment of Cancer Quality of Life Questionnaire - Core 30 (EORTC QLQ-C30), European Organization for Research and Treatment of Cancer Quality of Life Questionnaire - Breast Cancer 23 (EORTC QLQ-BR23), Functional Assessment of Cancer Therapy - General questionnaire (FACT-G), and Utility-Based Questionnaire-Cancer (UBQ-C); most used EQ-5D as the reference. Sociodemographic factors that affect health utilities, such as age, sex, income, and education, as well as disease progression, choice of utility elicitation method, and country settings, were identified within the journal articles. Most submissions to HTA bodies obtained utility values from the literature rather than exploring the HRQOL data obtained during clinical development. This was critiqued by the National Institute for Health and Clinical Excellence (NICE). Furthermore, the impact of age on utilities was highlighted by NICE and it was suggested that an age match of the study population should be attempted.

CONCLUSION

Health utilities are recorded across the globe to varying extents and using differing elicitation methods. Manufacturers seeking reimbursement need to be aware of the country-specific requirements for elicitation of health utilities.

Distal spike initiation zone location estimation by morphological simulation of ionic current filtering demonstrated in a novel model of an identified Drosophila motoneuron

Studying ion channel currents generated distally from the recording site is difficult because of artifacts caused by poor space clamp and membrane filtering. A computational model can quantify artifact parameters for correction by simulating the currents only if their exact anatomical location is known. We propose that the same artifacts that confound current recordings can help pinpoint the source of those currents by providing a signature of the neuron’s morphology. This method can improve the recording quality of currents initiated at the spike initiation zone (SIZ) that are often distal to the soma in invertebrate neurons. Drosophila being a valuable tool for characterizing ion currents, we estimated the SIZ location and quantified artifacts in an identified motoneuron, aCC/MN1-Ib, by constructing a novel multicompartmental model. Initial simulation of the measured biophysical channel properties in an isopotential Hodgkin-Huxley type neuron model partially replicated firing characteristics. Adding a second distal compartment, which contained spike-generating Na⁺ and K⁺ currents, was sufficient to simulate aCC’s in vivo activity signature. Matching this signature using a reconstructed morphology predicted that the SIZ is on aCC’s primary axon, 70 μm after the most distal dendritic branching point. From SIZ to soma, we observed and quantified selective morphological filtering of fast activating currents. Non-inactivating K⁺ currents are filtered ∼3 times less and despite their large magnitude at the soma they could be as distal as Na⁺ currents. The peak of transient component (NaT) of the voltage-activated Na⁺ current is also filtered more than the magnitude of slower persistent component (NaP), which can contribute to seizures. The corrected NaP/NaT ratio explains the previously observed discrepancy when the same channel is expressed in different cells. In summary, we used an in vivo signature to estimate ion channel location and recording artifacts, which can be applied to other neurons.

The study of ion channels is essential both for understanding normal brain function and for finding drug targets to treat neurological disease. Traditional experimental techniques remain challenging for recording ion channel currents accurately because of their locations in the neuron. Computer modeling of the three dimensional structure of neurons can provide a correction estimate for the measurement error introduced by neuronal membranes. To achieve this, we developed a modeling approach to localize, and correct for, distant ion channels. We demonstrated this approach by constructing novel computer models of an identified insect motor neuron, which provides a powerful model for studying the central nervous system. Through the study of electrical activity and genetic manipulations, it has been found that the persistent sodium current contributes to seizure. By modeling three dimensional structure, we were able to predict the location of these currents in the neuron, which were more distal than expected. Localizing sodium channels allowed us to predict their properties at origin, which favorably matched isolated recordings of these channels in more compact cells. This result is important in validating the use of heterologous compact cells to study insect sodium channels, and also demonstrates the usefulness of the presented modeling approach for studying channel physiology more generally.

Patient reported burden of asthma on resource use and productivity across 11 countries in Europe

Introduction

Asthma affects 30 million people in Western Europe, leading to substantial burden on healthcare systems and economies. REcognise Asthma and LInk to Symptoms and Experience (REALISE™) was a large European survey across 11 countries assessing patient attitudes and behaviors towards their asthma. The present study utilizes REALISE™ data to understand resource use and absenteeism in asthma.

Methods

Data were collected on absenteeism and healthcare resource use from 8000 asthma patients (aged 18–50 years) across the 11 countries. All data were patient reported. Odds ratios (ORs) were calculated against the country with the lowest proportion of respondents for hospitalization (as a proxy for lowest resource use).

Results

Patient characteristics were broadly similar across countries. However, self-reported asthma control status varied. More than 50% of respondents in most countries considered primary healthcare professionals (HCPs), i.e., general practitioners and nurses, the main HCP they see about their asthma. However, in some countries, specialists or nurses were considered the main HCP. Hospitalization was lowest amongst patients in the Netherlands. Resource use and productivity loss varied widely across the countries; ORs for hospitalization ranged from 1 in Sweden to 4 in Norway and for productivity loss from 0.6 in Sweden to 2.6 in Italy, compared with the Netherlands.

Conclusion

This study quantified utilization of healthcare resources in asthma (number of visits of HCPs, hospitalization, and accident and emergency visits) as well as absenteeism and showed that differences exist across countries. The differences in primary care and specialist use suggest a possible difference in healthcare delivery across countries.

Funding

Mundipharma International Limited, Cambridge, UK.

Electronic supplementary material

The online version of this article (doi:10.1007/s12325-015-0204-6) contains supplementary material, which is available to authorized users.

Miniature neurotransmission regulates Drosophila synaptic structural maturation

Miniature neurotransmission is the transsynaptic process where single synaptic vesicles spontaneously released from presynaptic neurons induce miniature postsynaptic potentials. Since their discovery over 60 years ago, miniature events have been found at every chemical synapse studied. However, the in vivo necessity for these small-amplitude events has remained enigmatic. Here, we show that miniature neurotransmission is required for the normal structural maturation of Drosophila glutamatergic synapses in a developmental role that is not shared by evoked neurotransmission. Conversely, we find that increasing miniature events is sufficient to induce synaptic terminal growth. We show that miniature neurotransmission acts locally at terminals to regulate synapse maturation via a Trio guanine nucleotide exchange factor (GEF) and Rac1 GTPase molecular signaling pathway. Our results establish that miniature neurotransmission, a universal but often-overlooked feature of synapses, has unique and essential functions in vivo.

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Miniature, but not evoked, neurotransmission is required for synapse development

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Miniature neurotransmission bidirectionally regulates synaptic terminal maturation

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Miniature events signal locally through the GEF Trio and the GTPase Rac1

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Miniature neurotransmission has unique and essential functions in vivo

The LIM-homeodomain protein islet dictates motor neuron electrical properties by regulating K(+) channel expression

Neuron electrical properties are critical to function and generally subtype specific, as are patterns of axonal and dendritic projections. Specification of motoneuron morphology and axon pathfinding has been studied extensively, implicating the combinatorial action of Lim-homeodomain transcription factors. However, the specification of electrical properties is not understood. Here, we address the key issues of whether the same transcription factors that specify morphology also determine subtype specific electrical properties. We show that Drosophila motoneuron subtypes express different K⁺ currents and that these are regulated by the conserved Lim-homeodomain transcription factor Islet. Specifically, Islet is sufficient to repress a Shaker-mediated A-type K⁺ current, most likely due to a direct transcriptional effect. A reduction in Shaker increases the frequency of action potential firing. Our results demonstrate the deterministic role of Islet on the excitability patterns characteristic of motoneuron subtypes.

Feedback network controls photoreceptor output at the layer of first visual synapses in Drosophila

At the layer of first visual synapses, information from photoreceptors is processed and transmitted towards the brain. In fly compound eye, output from photoreceptors (R1-R6) that share the same visual field is pooled and transmitted via histaminergic synapses to two classes of interneuron, large monopolar cells (LMCs) and amacrine cells (ACs). The interneurons also feed back to photoreceptor terminals via numerous ligand-gated synapses, yet the significance of these connections has remained a mystery. We investigated the role of feedback synapses by comparing intracellular responses of photoreceptors and LMCs in wild-type Drosophila and in synaptic mutants, to light and current pulses and to naturalistic light stimuli. The recordings were further subjected to rigorous statistical and information-theoretical analysis. We show that the feedback synapses form a negative feedback loop that controls the speed and amplitude of photoreceptor responses and hence the quality of the transmitted signals. These results highlight the benefits of feedback synapses for neural information processing, and suggest that similar coding strategies could be used in other nervous systems.

Impact of rearing conditions and short-term light exposure on signaling performance in Drosophila photoreceptors

The amount of visual information an animal can extract from its environment is ultimately limited by the signaling performance of its photoreceptors. To maximize their performance, photoreceptors must be able to accommodate large changes in input caused by the dynamic properties of the visual environment and the animal's own behavior. This is likely to require a range of adaptation mechanisms operating over multiple time scales. Using intracellular recordings, we investigated the effects of developmental light rearing conditions and the effects of 2 h light or dark exposure prior the experiment on the signaling performance of adult Drosophila melanogaster photoreceptors. We show that light-rearing amplifies photoreceptors' voltage responses to light contrast changes by >or =20% and accelerates them by 3 ms. We argue that these differences mostly reflect changes in the timing of the early phototransduction reactions, some of which are persistent. However, being born and nurtured in certain lighting conditions does not set an ultimate limit for the signaling performance of Drosophila photoreceptors. Two-hour light exposure prior to the experiment can improve the information capacity of dark-reared photoreceptors close to the values of light-reared photoreceptors by reducing voltage noise. This effect may originate from plastic changes in the utilization of phototransduction proteins and ion channels.