Does the feedback of blood results in observational studies influence response and consent? A randomised study of the Understanding Society Innovation Panel.

BACKGROUND: While medical studies generally provide health feedback to participants, in observational studies this is not always the case due to logistical and financial difficulties, or concerns about changing observed behaviours. However, evidence suggests that lack of feedback may deter participants from providing biological samples. This paper investigates the effect of offering feedback of blood results on participation in biomeasure sample collection. METHODS: Participants aged 16 and over from a longitudinal study - the Understanding Society Innovation Panel-were randomised to three arms - nurse interviewer, interviewer, web survey - and invited to participate in biomeasures data collection. Within each arm they were randomised to receive feedback of their blood results or not. For those interviewed by a nurse both venous and dried blood samples (DBS) were taken in the interview. For the other two arms, they were asked if they would be willing to take a sample, and if they agreed a DBS kit was left or sent to them so the participant could take their own sample and return it. Blood samples were analysed and, if in the feedback arms, participants were sent their total cholesterol and HbA1c results. Response rates for feedback and non-feedback groups were compared: overall; in each arm of the study; by socio-demographic and health characteristics; and by previous study participation. Logistic regression models of providing a blood sample by feedback group and data collection approach controlling for confounders were calculated. RESULTS: Overall 2162 (80.3% of individuals in responding households) took part in the survey; of those 1053 (48.7%) consented to provide a blood sample. Being offered feedback had little effect on overall participation but did increase consent to provide a blood sample (unadjusted OR 1.38; CI: 1.16-1.64). Controlling for participant characteristics, the effect of feedback was highest among web participants (1.55; 1.11-2.17), followed by interview participants (1.35; 0.99 -1.84) and then nurse interview participants (1.30; 0.89-1.92). CONCLUSIONS: Offering feedback of blood results increased willingness to give samples, especially for those taking part in a web survey.

The heterogeneous and regressive consequences of COVID-19: Evidence from high quality panel data.

Using new data from the first two waves of the Understanding Society COVID-19 Study collected in April and in May 2020 in the UK, we study the labour market shocks that individuals experienced in the first wave of the pandemic, and the steps they and their households took to cope with those shocks. Understanding Society is based on probability samples and the Covid-19 Study is constructed carefully to support valid population inferences. The Covid-19 Study collected novel data on the mitigation strategies that individuals and households employ. Further, prior observation of respondents in the panel allows us to characterize regressivity with respect to pre-pandemic economic positions. Our key findings are that those with precarious employment, aged under 30 and from minority ethnic groups faced the biggest labour market shocks. Almost 50% of individuals have experienced declines in household earnings of at least 10%, but declines are most severe in the bottom pre-pandemic income quintiles. Methods of mitigation vary substantially across groups: borrowing and transfers from family and friends are most prevalent among those most in need.

The health benefits of a targeted cash transfer: The UK Winter Fuel Payment.

Each year, the UK records 25,000 or more excess winter deaths, primarily among the elderly. A key policy response is the "Winter Fuel Payment" (WFP), a labelled but unconditional cash transfer to households with a member above the female state pension age. The WFP has been shown to raise fuel spending among eligible households. We examine the causal effect of the WFP on health outcomes, including self-reports of chest infection, measured hypertension, and biomarkers of infection and inflammation. We find a robust, 6 percentage point reduction in the incidence of high levels of serum fibrinogen. Reductions in other disease markers point to health benefits, but the estimated effects are less robust.

A randomised study of nurse collected venous blood and self-collected dried blood spots for the assessment of cardiovascular risk factors in the Understanding Society Innovation Panel.

Dried blood spot (DBS) sample collection has been suggested as a less invasive, cheaper and more convenient alternative to venepuncture, which requires trained personnel, making it a potentially viable approach for self-collection of blood on a large scale. We examine whether participants in a longitudinal survey were willing to provide a DBS sample in different interview settings, and how resulting cardiovascular risk biomarkers compared with those from venous blood to calculate clinical risk. Participants of the Understanding Society Innovation Panel, a representative sample of UK households, were randomly assigned to three modes of interview. Most participants (84%) were interviewed in their allocated mode. Participants (n = 2162) were interviewed by a nurse who collected both a blood sample by venepuncture and a DBS card ('nurse collection') or participants were seen by an interviewer or took part in the survey online to self-collect a DBS card ('self-collection'). All DBS cards were returned in the post after the sample had dried. Lipids (total cholesterol, HDL-cholesterol, triglycerides), HbA1c and C-reactive protein were measured in venous and DBS samples and equivalence was calculated. The resultant values were used to confirm equivalent prevalence of risk of cardiovascular disease in each type of blood sample by mode of participation. Of participants interviewed by a nurse 69% consented to venous blood sample and 74% to a DBS sample, while in the self-collection modes, 35% consented to DBS collection. Demographic characteristics of participants in self-collection mode was not different to those in nurse collection mode. The percentage of participants with clinically raised biomarkers did not significantly differ between type of blood collection (for example, 62% had high cholesterol (> 5 mmol/l) measured by venepuncture and 67% had high cholesterol within the self-collected DBS sample (p = 0.13)). While self-collected DBS sampling had a lower response rate to DBS collected by a nurse, participation did not vary by key demographic characteristics. This study demonstrates that DBS collection is a feasible method of sample collection that can provide acceptable measures of clinically relevant biomarkers, enabling the calculation of population levels of cardiovascular disease risk.

Physician labour supply in Canada: a cohort analysis.

This paper employs a cohort analysis to examine the relative importance of different factors in explaining changes in the number of hours spent in direct patient care by Canadian general/family practitioners (GPs) over the period 1982-2003. Cohorts are defined by year of graduation from medical school. The results for male GPs indicate that there is little age effect on hours of direct patient care, especially among physicians aged 35-55, there is no strong cohort effect on hours of direct patient care, but there is a secular decline in hours of direct patient care over the period. The results for female GPs indicate that female physicians on average work fewer hours than male physicians, there is a clear age effect on hours of direct patient care, there is no strong cohort effect, and there has been little secular change in average hours of direct patient care. The changing behaviour of male GPs accounted for a greater proportion of the overall decline in hours of direct patient care from the 1980s through the mid-1990 s than did the growing proportion of female GPs in the physician stock.

Returns to scale in food preparation and the Deaton-Paxson puzzle.

We consider returns to scale in food preparation as a potential resolution of a puzzle raised by Deaton and Paxson (Journal of Political Economy, 106(5), 897-930, 1998). We clarify the conditions under which returns to scale in food preparation can resolve the puzzle. The key requirement is that foods are heterogeneous in time costs. We then show that detailed food expenditure and time use data are consistent with larger households shifting to more time intensive foods.

The reliability of self-assessed health status.

The use of self-assessed health status (SAHS) as a measure of health is common in empirical research. We analyse a unique Australian survey in which a random sub-sample of respondents answer a standard self-assessed health question twice-before and after an additional set of health related questions. A total of 28% of respondents change their reported health status. Response reliability is related to age, income and occupation. We also compare the responses of these individuals to other respondents who are queried only once, to isolate effects of question order and mode of administration.

The effects of drug subsidies on out-of-pocket prescription drug expenditures by seniors: regional evidence from Canada.

Between 1970 and 1986, all Canadian provinces introduced some version of a prescription drug subsidy for those aged 65 years or over and since 1986, all the provinces have increased copayments or deductibles to some degree. Employing a first-order approximation to the welfare gains from a subsidy, we find evidence that these subsidies have been less redistributive than an absolute per household cash transfer but slightly more redistributive than a transfer that would increase each household's income by the same percentage. Such evidence may have relevance for predicting the redistributive effects of a potential national prescription drug plan for seniors in the US.

The effect of health changes and long-term health on the work activity of older Canadians.

Using longitudinal data from the Canadian National Population Health Survey (NPHS), we study the relationship between health and employment among older Canadians. We focus on two issues: (1) the possible problems with self-reported health, including endogeneity and measurement error, and (2) the relative importance of health changes and long-term health in the decision to work. We contrast estimates of the impact of health on employment using self-assessed health, an objective health index contained in the NPHS - the HUI3, and a 'purged' health stock measure. Our results suggest that health has an economically significant effect on employment probabilities for Canadian men and women aged 50-64, and that this effect is underestimated by simple estimates based on self-assessed health. We also corroborate recent US and UK findings that changes in health are important in the work decision.