Association of Large Financial Incentives With COVID-19 Vaccination Uptake Among Employees of a Large Private Company.

Introduction

Without a federal mandate,[1] motivating employees to receive COVID-19 vaccination is a challenge. For influenza vaccination, Nowalk et al[2] found that a small ($5) financial incentive increased uptake by 3.4 percentage points in a workplace-based program. However, financial incentives to increase COVID-19 vaccination uptake have mixed outcomes. Campos-Mercade et al[3] found that a moderate ($24) cash incentive increased COVID-19 vaccine uptake by 4.2 percentage points, whereas Wong et al[4] found that $25 was associated with slower decline of vaccination uptake. Acharya and Dhakal[5] found that large but uncertain incentives (lottery programs) across 11 states had mixed success.

On August 6, 2021, a large medical device manufacturer announced a vaccination incentive program for US-based employees. The program required that all employees watch and acknowledge online educational information. Employees were also encouraged to report their vaccination status. Those fully vaccinated for COVID-19 by September 30, 2021, would receive a $1000 incentive if able to show proof of vaccination. The incentive was paid in October 2021.

Methods

The University of Minnesota institutional review board determined that this study used deidentified data and did not involve human participants, so this study was deemed exempt and granted a waiver of informed patient consent. This cross-sectional study followed the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) reporting guideline.

Each employee’s vaccination status was logged in a human resources database in addition to the vaccine brand and date(s) of each dose. Employees could update their status through September 30, 2021. Program data were combined with personnel data (age, salary band, and self-classification of sex and race) to determine whether vaccination uptake varied within employee subgroups. Employees considered not fully vaccinated prior to the incentive were those who had not received any vaccine dose or had only received 1 mRNA dose more than 50 days prior to the announcement.

We conducted a cross-sectional study using χ2 tests and interrupted time series analyses between May 14 and September 30, 2021, to estimate changes in weekly vaccination uptake before and after the program announcement. In post hoc analyses, we described patterns of vaccine uptake by demographic subgroups. Two-sided P < .05 was considered significant. All statistical analyses were conducted using Stata 15 MP (StataCorp) from November to December 2021.

Results

By September 30, 2021, 2055 of 2099 (97.90%) employees eligible for the financial incentive reported their vaccination status and were included in the analysis. Among the 2055 eligible employees, 257 (12.5%) were Asian, 140 (6.8%) were Hispanic or Latino, 1552 (75.5%) were White, and 1125 (54.7%) were female. Prior to the incentive announcement, 1555 employees (75.7%) were fully vaccinated compared with 1769 employees (86.1%) after—a 10.4 percentage point increase. Among 500 employees not fully vaccinated prior to the announcement, 214 (42.8%) became fully vaccinated by September 30, 2021 (Table).

Table.

Characteristics of Employees Eligible for COVID-19 Financial Incentive

Characteristic	No. (%)
	All employees (N = 2055)		Not fully vaccinated before incentive (n = 500)
	Fully vaccinated before incentive (n = 1555)	Fully vaccinated after incentive (n = 1769)	Not fully vaccinated before incentive (n = 500)	Fully vaccinated after incentive (n = 214)	Change %	P value
Race
American Indian or Alaskan Native	4 (0.26)	4 (0.23)	2 (0.40)	0	0.00	.21
Asian	236 (15.18)	247 (13.96)	21 (4.20)	11 (5.14)	52.38
Black or African American	30 (1.93)	32 (1.81)	13 (2.60)	2 (0.93)	15.38
Hispanic or Latino	117 (7.52)	126 (7.12)	23 (4.60)	9 (4.21)	39.13
Native Hawaiian or other Pacific Islander	0 (0.00)	2 (0.11)	2 (0.40)	2 (0.93)	100.00
Not specified	20 (1.29)	23 (1.30)	8 (1.60)	3 (1.40)	37.50
≥2 Races	18 (1.16)	21 (1.19)	9 (1.80)	3 (1.40)	33.33
White	1130 (72.67)	1314 (72.28)	422 (84.40)	184 (85.98)	43.60
Sex
Female	798 (51.32)	946 (53.48)	327 (65.40)	148 (69.16)	45.26	.13
Male	757 (48.68)	823 (46.52)	173 (34.60)	66 (30.84)	38.15
Age band, y
17-24	50 (3.22)	57 (3.22)	14 (2.80)	7 (3.27)	50.00	.18
25-39	504 (32.41)	575 (32.50)	182 (36.40)	71 (33.18)	39.01
40-49	362 (23.28)	409 (23.12)	120 (24.00)	47 (21.96)	37.30
50-64	579 (37.23)	660 (37.31)	161 (32.20)	81 (37.85)	48.80
≥65	60 (3.86)	68 (3.84)	23 (4.60)	8 (3.74)	32.00
Salary band level
3 (highest)	51 (3.28)	54 (3.05)	6 (1.20)	3 (1.40)	50.00	.64
4	194 (12.48)	213 (12.04)	48 (9.60)	19 (8.88)	39.58
5	280 (18.01)	292 (16.51)	40 (8.00)	12 (5.61)	30.00
6	393 (25.27)	450 (25.44)	131 (26.20)	57 (26.64)	43.51
7	181 (11.64)	221 (12.49)	89 (17.80)	40 (18.69)	44.94
8 (lowest)	456 (29.32)	539 (30.47)	186 (37.20)	83 (38.79)	44.62

On the week of the announcement, there was an increase of 54 employees (95% CI, 29-79 employees; P = .001) receiving their first dose of vaccine (Figure A). Similarly, there was an increase of 70 employees (95% CI, 30-110 employees; P = .002) receiving their second dose (Figure B). Prior to the incentive announcement, there were flat weekly trends in employees receiving first and second doses.

Figure.

Weekly Number of Employees Receiving COVID-19 Vaccine

Vaccination uptake was analyzed before and after the incentive announcement by various demographic groups. A higher percentage of previously unvaccinated female (45.3% [148 of 327]) vs male (38.2% [66 of 173]) employees were vaccinated after the incentive (Table). We observed similar patterns in previously unvaccinated Asian employees (52.4% [11 of 21]) compared with White (43.6% [184 of 422]) and Black or African American (15.4% [2 of 13]) employees. There were no significant differences by age groups or salary levels.

Discussion

Our results found that a workplace-based large ($1000) guaranteed financial incentive was associated with increased COVID-19 vaccine uptake. Limitations of the study include absence of a control group, being limited to a single company, and possible confounding with full approval of the Pfizer vaccine by the FDA on August 23, 2021.