The Sting of Rejection: Deferring Blood Donors due to Low Hemoglobin Values Reduces Future Returns.

BACKGROUND: Roughly one quarter of short-term temporary deferrals (STTD) of blood donors are low-hemoglobin deferrals (LHD), i.e. STTD due to a hemoglobin (Hb) value falling below a cutoff of 125 g/L for female and 135 g/L for male donors. Since voluntarily donating blood is a prosocial activity, donors may perceive deferral as social exclusion, which can cause social pain, decrease self-esteem, and lead to antisocial behavior. However, little is known about the causal impacts of LHD on donor return. STUDY DESIGN AND METHODS: We conducted a quasi-experiment with 80,060 donors invited to blood drives in the canton of Zurich, Switzerland, between 2009 and 2014. Within a narrow window of Hb values around the predetermined cutoff, the rate of LHD jumps discontinuously. This discontinuous jump allows us to quantify the causal effects of LHD on donor return, as it is uncorrelated with other unobserved factors that may also affect donor return. RESULTS: We found different behavioral reactions to LHD for female and male donors. Female donors do not react to the first LHD. However, after any repeated LHD, they are 13.53 percentage points (p <0.001) less likely to make at least 1 donation attempt within the next 18 months and make 0.389 fewer donation attempts (p <0.001). Male donors react to the first LHD. They are 5.32 percentage points (p = 0.139) less likely to make at least 1 donation attempt over the next 18 months and make 0.227 (p = 0.018) fewer donation attempts. After any repeated LHD, male donors are 13.30 percentage points (p = 0.004) less likely to make at least 1 donation attempt and make 0.152 (p = 0.308) fewer donation attempts. CONCLUSION: LHD have detrimental impacts on donor return, especially if they occur repeatedly - suggesting that avoiding false LHD and helping donors to better cope with them helps to maintain the pool of prospective donors.

Maternal mental health and social support from online communities during pregnancy.

Social determinants of public health have gained increasing attention. This paper studied whether social support from online communities related to maternal mental health. We focused on online maternity communities that group users with a similar prenatal status to facilitate their exchange of personal experiences and knowledge about maternal caring during pregnancy. Such online maternity communities are getting increasingly popular and can be found across countries and societies. We invited users-currently pregnant and gave birth within 1 year at the time of the study-from one such community in China to participate in a survey. The survey measured their perceived social support (PSS) exclusively from the peer group in the online community, their mental health and newborns' birth outcomes (N = 500). Users reported high score in PSS from the online peer group which was comparable to the ones from family, significant other and friends in other studies. We used linear regression models to examine the effects of PSS on mental health and birth outcomes. We found that a one-point increase in the PSS score was associated with a 0.19-point (p < 0.1) decrease in the prenatal depression and a 0.26-point (p < 0.01) decrease in the postnatal depression, which was equivalent to 3% and 4.5% of the average respectively. Moreover, a one-point increase in the PSS score was associated with a 14.49-gram increase in a newborn's weight (p < 0.01).

Spillovers of prosocial motivation: Evidence from an intervention study on blood donors.

Blood donations are increasingly important for medical procedures, while meeting demand is challenging. This paper studies the role of spillovers arising from social interactions in the context of voluntary blood donations. We analyze a large-scale intervention among pairs of blood donors who live at the same street address. A quasi-random phone call provides the instrument for identifying the extent to which the propensity to donate spills over within these pairs. Spillovers transmit 41% to 46% of the behavioral impulse from one donor to the peer. This creates a significant social multiplier, ranging between 1.7 and 1.85. There is no evidence that these spillovers lead to intertemporal substitution. Taken together, our findings indicate that policy interventions have a substantially larger effect when targeted towards pairs instead of isolated individuals.