A risk-risk trade-off assessment of climate-induced mortality risk changes

The impact of climate change on human health was identified as a priority for the UN COP26 conference. In this article, we consider climate-induced changes to mortality risks and how to incorporate these formally in the policy appraisal process. In the United Kingdom (UK), the Value of Statistical Life (VSL) is used to monetarize the benefits of policies to reduce mortality risks but it remains an open, empirical question as to whether the current VSL (£2.14 million per fatality prevented, December 2021 values) for traffic accidents should be applied in other contexts without any modification and particularly for extreme weather event fatalities. Using a representative sample of the UK population, we aim to estimate and better understand the trade-offs people make when comparing mortality risks, drawing on psychological insights from construal level and regulatory focus theories. We design a stated preference survey using a relative valuation framework with nonmonetary, risk-risk trade-off questions between extreme weather event and traffic accident mortality risks. We find evidence of an extreme weather event risk premium of 1.2-1.6 (implying a climate-related VSL of £2.52-£3.41 million). We also find that participants who are psychologically close to climate change (based on construal level theory), weigh reducing extreme weather event mortality risks almost two times that of reducing traffic accident mortality risks.

A Novel Application of Risk-Risk Tradeoffs in Occupational Health: Nurses' Occupational Asthma and Infection Risk Perceptions Related to Cleaning and Disinfection during COVID-19

BACKGROUND

Nurses face the risk of new onset occupational asthma (OA) due to exposures to cleaning and disinfection (C&D) agents used to prevent infections in healthcare facilities. The objective of this study was to measure nurses' preferences when presented with simultaneous OA and respiratory viral infection (e.g., COVID-19) risks related to increased/decreased C&D activities.

METHODS

Nurses working in healthcare for ≥1 year and without physician-diagnosed asthma were recruited for an online anonymous survey, including four risk-risk tradeoff scenarios between OA and respiratory infection with subsequent recovery (Infect and Recovery) or subsequent death (Infect and Death). Nurses were presented with baseline risks at hypothetical "Hospital 1", and were asked to choose Hospital 2 (increased OA risk to maintain infection risk), Hospital 3 (increased infection risk to maintain OA risk), or indicate that they were equally happy.

RESULTS

Over 70% of nurses were willing to increase infection risk to maintain baseline OA risk if they were confident they would recover from the infection. However, even when the risk of infection leading to death was much lower than OA, most nurses were not willing to accept a larger (but still small) risk of death to avoid doubling their OA risk. Age, work experience, and ever having contracted or knowing anyone who has contracted a respiratory viral infection at work influenced choices.

CONCLUSIONS

We demonstrate the novel application of a risk-risk tradeoff framework to address an occupational health issue. However, more data are needed to test the generalizability of the risk preferences found in this specific risk-risk tradeoff context.

Association between time preference, present-bias and physical activity: implications for designing behavior change interventions

BACKGROUND

The decision to initiate or maintain a healthy habit, such as physical activity involves a trade-off between a short-term cost, such as time and effort, which are commonly identified as barriers to physical activity, and a long-term health benefit. Research suggests that individual time preference may be associated with unhealthy behaviors. However, empirical evidence of this for physical activity is scant. This study investigated the relationship between time preference and physical activity, and how this might influence behavior change.

METHODS

Employees (n = 176; mean age 42.2 years) who participated in a physical activity intervention were invited to take part in a behavioral economic field experiment. Two economic experiments, using multiple price lists and monetary trade-off tables involving real money choices, were conducted face-to-face with participants to measure the two components of time preference, namely present-bias and discount rate. Together with individual risk preferences, these three variables were jointly estimated by maximum likelihood. These three parameters were expressed as a linear function of the levels of physical activity while controlling for socio-demographic variables within the same maximum likelihood framework.

RESULTS

Those who were present-biased and who had higher discount rates did significantly less physical activity than their patient and non present-biased counterparts. A 3% lower discount rate and 1.14 unit decrement in the present-bias parameter was associated with a 30 min increase of physical activity per week. This negative association was more significant for certain sub-groups, such as younger and married adults and those with higher staff grade and those who have children. Participants who dropped out of the study earlier were more present-biased.

CONCLUSIONS

Results demonstrated that discount rate and present-biasedness have a significant impact on physical activity levels. Such concepts have been largely overlooked and underutilized in physical activity interventions. Promising implications include 1) utilizing individuals' time preferences to better target interventions; 2) taking account of time preferences in the intervention design; 3) interventions attempting to correct for present-biasedness.

Comparing Increments in Utility of Health: An Individual-based Approach

BACKGROUND

Many economic evaluations of health care changes rely on quality-adjusted life year (QALY) estimates. Notably, though, the QALY approach values health states rather than changes in health states. Hence, a gain in utility of health is only indirectly valued through an ex ante preference elicitation of health states and the subsequent subtraction of health state values from one another, rather than being valued directly. There is therefore an underlying assumption that individuals, from an ex ante perspective ceteris paribus, would be indifferent between equal utility increments from health states with different baseline utilities.

OBJECTIVE

The aim of this paper is to develop a method that would allow us to measure individual-based preferences over utility increments from different baselines. We elicit our data using face-to-face interviews on a sample of UK individuals.

RESULTS

Overall, we find that gains of "equal" utility increments from different baselines are not found to be equally preferable by the individual.

CONCLUSIONS

The results indicate that the subtraction approach could lead to sub-optimal resource allocations and suggest that a new approach which values health changes directly would better reflect individual preferences. This paper provides the foundations for a method to achieve this.

Did people "buy" what was "sold"? A qualitative evaluation of a contingent valuation survey information set for gains in life expectancy

A number of stated preferences studies have estimated a monetary value for the gains in life expectancy resulting from pollution control, using a Value of a Life Year (VOLY) approach. However, life expectancy gains are a complex concept and no attempt has been made, to date, to investigate peoples' understanding of what it is they are being asked to value. Past practice has been to focus on the outcome of a policy i.e. a gain to the average person of X months', providing no details on how the individual receives, or experiences this gain, a potentially important attribute to value. This paper sets up and reports the results from a structured debriefing exercise to qualitatively investigate an alternative approach which explicitly emphasises how this gain is delivered (on-going reductions in the risk of death). We find that, for the majority of respondents, the approach is effective in communicating the on-going nature of the gain and reduces or eliminates the use of the (incorrect) heuristic that it is an 'add-on' at the end of life, in poor health. Further refinements are required, however, to communicate the cumulative nature of these risk reductions and the lack of impact on quality of life. The lesson for stated preference studies in general is that structured debriefings can be very useful, highlighting such issues as the persistence of ill-defined attributes and the difficulties that respondents may encounter setting aside their preferences over attributes of the good that should not be included in the valuation.

Low-dose lenograstim is as effective as standard dose in shortening neutrophil engraftment time following myeloablative chemotherapy and peripheral blood progenitor cell rescue

Granulocyte colony-stimulating factor (G-CSF) is widely used following myeloablative chemotherapy (high-dose therapy; HDT) and peripheral blood progenitor cell rescue (PBPCR) to reduce neutrophil engraftment time. The dose and duration required to gain maximum clinical and economic benefit has not been fully investigated. This double blind placebo-controlled randomised trial was performed to determine whether short course low-dose or standard-dose Lenograstim (L) would influence recovery of haematopoiesis following HDT and PBPCR. Sixty-one patients were randomised between May 1999 and November 2004, to receive standard-dose lenograstim (263 microg/d), low-dose lenograstim (105 microg/d) or placebo injections. These commenced on day +5 following PBPCR and continued until neutrophil engraftment [absolute neutrophil count (ANC)] > or = 0.5 x 10(9)/l. Patients received standard supportive care until haemopoietic recovery. Both standard- and low-dose lenograstim resulted in a significantly shorter median time to neutrophil recovery (ANC > or = 0.1 x 10(9)/l:10.0 vs. 11.0 d, P = 0.025; ANC > or = 0.5 x 10(9)/l:11.0 vs. 14.0 d, P = 0.0002) compared with placebo. There was no significant difference in blood product support, antibiotic usage, documented infection, overall survival or relapse-free survival between the groups. Short course low-dose lenograstim is as effective as standard-dose in reducing neutrophil engraftment time following HDT and PBPCR.

Randomised, placebo-controlled, trial comparing low dose versus standard dose Lenograstim (L) following myeloablative chemotherapy (HDT) and peripheral blood progenitor cell rescue (PBPCR) for lymphoma

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Background: This trial was performed to determine whether low-dose or standard dose L would influence recovery of haematopoiesis following HDT and PBPCR. Methods: 61 patients (pts) with non-Hodgkin lymphoma (40) or Hodgkin’s disease (21) undergoing HDT were randomised. Pts had normal peripheral blood counts prior to HDT (Hb ≥100g/L, total white cell count ≥ 3.0, neutrophils (N) ≥ 1.0 and platelets ≥ 50, and had a minimum 2.5 million CD34+ cells/kg PBPC previously collected following mobilisation with Cyclophosphamide 3g/m2 and G-CSF. All received HDT with BCNU 300mg/m2 d-7, Etoposide 200mg/m2 od d-5-d-2, Cytosine arabinoside 200mg/m2 bd d-5-d-2 and Melphalan 140mg/m2 d-1 before return of PBPC on D0. Pts were allocated standard dose L 263mcg daily (20 pts), low dose L 105mcg daily (21 pts) or placebo injections (20 pts). These commenced on day +5 following PBPCR and continued until N≥0.5. Pts received standard supportive care including prophylactic Fluconazole and Acyclovir, but not routine antibacterial prophylaxis, until haemopoietic recovery. Results: L at any dose resulted in a significantly shorter median time to N recovery ≥0.1 (10.0 vs 11.0 days, P=0.02) and ≥0.5 (11.0 vs 14.0 days, p=0.0003) compared to placebo. The only significant difference between standard- and low-dose L was in hospital stay (21.0 vs 22.0 days, p=0.04), however L at any dose showed a significant reduction over placebo (22.0 vs 23.0 days, p=0.01). Conclusions: Short course low dose L is as effective as standard dose in reducing neutrophil engraftment time following HDT and PBSCR. L at any dose reduces hospital stay when compared to placebo. This approach should be considered for those patients in whom growth factor support is indicated. Long-term follow-up data will be presented.

[Table: see text]

No significant financial relationships to disclose.

Interallelic complementation in an inborn error of metabolism: genetic heterogeneity in argininosuccinate lyase deficiency

We used complementation analysis as a probe for the detection of genetic heterogeneity within a single locus affected in a human disease, argininosuccinate lyase (L-argininosuccinate arginine-lyase, EC 4.3.2.1) deficiency. Fibroblasts cultured from 28 unrelated patients were fused in all possible pairwise combinations, and the argininosuccinate lyase activity in heterokaryons was assayed by measuring the incorporation of 14C from L-[ureido-14C]citrulline into acid-precipitable material. Partial complementation was observed in fusions involving 20 of the 28 strains, with the lyase activity increasing from 2- to 10-fold. Thirteen of the mutants were identified by the complementation analysis as being phenotypically unique. Of the 20 complementing strains, 3 were remarkable because they participated in all but 2 of the 32 positive complementation tests; 2 others constituted a unique subgroup that produced the highest increases in argininosuccinate lyase activity of all fusions. The 8 strains that did not complement any others consisted of two types: 3 mutants with the highest residual argininosuccinate lyase activity of all strains and 5 mutants with low residual activity. All of the mutants mapped to a single major complementation group. The data could be summarized as a circular complementation map with an attached linear tail, the mutants being distributed among 12 subgroups in a complex pattern. We conclude that all of these mutants are affected at a single locus, that extensive genetic heterogeneity is present in the mutant population, and that the affected locus in argininosuccinate lyase deficiency is likely to be the structural gene coding for that enzyme.