Skip main navigation

Military Health System

Clear Your Browser Cache

This website has recently undergone changes. Users finding unexpected concerns may care to clear their browser's cache to ensure a seamless experience.

Surveillance Snapshot: A Simple Model Estimating the Impact of COVID-19 on Lost Duty Days Among U.S. Service Members

Image of Cover 4 Snapshot_ A simple model. U.S. Navy Hospital Corpsman 2nd Class Julian Gordon, left, a preventative medicine technician with Marine Rotational Force - Darwin, administers a COVID-19 test to a U.S. Marine with MRF-D, at Royal Australian Air Force Base, Darwin, NT, Australia, March 22, 2021. Marines and Sailors with MRF-D are required to conduct strict COVID-19 mitigation procedures prior to arrival in Darwin, in compliance with Northern Territory Health Authorities. All service members must provide three documented negative COVID-19 swab tests throughout their travel and prior to being released from a 14-day quarantine period. (U.S. Marine Corps photo by Sgt. Micha Pierce)

Since the start of the coronavirus disease 2019 (COVID-19) pandemic, the Department of Defense (DOD) has reported 226,510 cases of COVID-19 among military members as of 25 Aug. 2021.1 Managing COVID-19 infections and implementing quarantines of their contacts could alter the training and mission plans for most, if not all, military units. Although there was robust prognostication regarding the impact of COVID-19 on lost duty days in the early months of the pandemic,2,3 little has been published in this area since then.

Simple modeling can provide an important estimate of the impact of COVID-19 on lost duty days among U.S. service members. The model used in this analysis assumes that each reported case undergoes 10 days of isolation and allows for variation in the number of close contacts (e.g., low [2], medium [4] and high [7]) and the length of quarantine (7 or 14 days). This model estimates the impact of a single COVID-19 case for each of the possible values of close contacts and quarantine length and also extrapolates the DOD-wide impact in terms of number of lost duty days (Table).

The model is a gross approximation of lost duty days and may both underestimate and overestimate lost duty days due to several factors. The model ignores the lost duty days of the 34 deaths and 2,036 hospitalizations among military service members reported by DOD since the start of the pandemic.1 This model also does not take into account the indirect lost duty days affecting service members charged with special duties in tracking, caring for, and administratively handling service members in isolation and quarantine. It also ignores the lost duty days of cases diagnosed in family members and the impact of lost duty days on non-military close contacts, including family members and DOD civilian employees. Furthermore, this model does not estimate the cumulative impact on unit readiness of multiple simultaneous or consecutive COVID-19 infections within a command. Finally, this model may overestimate lost duty days by including weekend days and it is unclear if the military members included in the DOD case report1 include inactivated reserve/Guard members who may not be on duty.

The COVID-19 pandemic has adversely impacted the availability of service members to unit Commanders. Using this model, one can estimate a best-case scenario of the loss of 0.71% of all duty days, with a worst-case scenario of the loss of around 3.2% of all duty days in the DOD during the period of March 1, 2020 to Aug. 25, 2021. When this loss is placed in the context of 3 to 8 members of a unit being unavailable for a mission, deployment, or training event due to a single infection, the impact on unit readiness is easily seen. Preventing a single case has a far-reaching impact on readiness, conserving 24–98 duty days of availability to Commanders. Although some service members were able to recover a portion of these lost days by teleworking, they represent the minority and were primarily among higher ranks.

Prevention of COVID-19 infections can have a significant positive impact on service member availability for missions and training. Ongoing efforts using all available infection prevention tools, including immunization, non-pharmaceutical interventions, and policies designed to prevent new infections should be pursued by Commanders and leaders at all levels of the DOD in order to optimize training tempo and readiness activities.

Author affiliations: Department of Public Health, Madigan Army Medical Center, U.S. Army, WA (LTC Mease and CPT Smith).

Disclaimer: The views expressed are those of the authors and do not reflect the official policy of the Department of the Army, the Department of Defense, or the U.S. Government.

References

  1. Coronavirus: DOD Response. U.S. Department of Defense. Published 3 May 2021. Accessed 25 Aug. 2021. https://www.defense.gov/Explore/Spotlight/Coronavirus
  2. Burke T, Dycus C, O'Hanlon M, Reid E, Worst J. COVID-19 and military readiness: Preparing for the long game. Brookings. Published April 22, 2020. Accessed 4 May 2021. https://www.brookings.edu/blog/order-from-chaos/2020/04/22/covid-19-and-military-readiness-preparing-for-the-long-game
  3. DiEuliis D, Junor L. Ready or Not: Regaining Military Readiness during COVID19. Inst Natl Strateg Stud. Published online April 10, 2020. Accessed 4 May 2021. https://inss.ndu.edu/Media/News/Article/2145282/ready-or-not-regaining-military-readiness-during-covid19 

TABLE. Impact of quarantine length (7 versus 14 days) on military readiness, by lost duty days after a COVID-19 infection, as of 25 Aug 2021

You also may be interested in...

Article
Apr 1, 2019

Modeling Lyme Disease Host Animal Habitat Suitability, West Point, New York

A deer basks in the morning sun at Joint Base San Antonio-Fort Sam Houston, Texas.  (Photo Courtesy: U.S. Air Force)

As the most frequently reported vector-borne disease among active component U.S. service members, with an incidence rate of 16 cases per 100,000 person-years in 2011, Lyme disease poses both a challenge to health care providers in the Military Health System and a threat to military readiness. Spread through the bite of an infected blacklegged tick, ...

Article
Mar 1, 2019

Sexually Transmitted Infections, Active Component, U.S. Armed Forces, 2010–2018

Anopheles merus

This report summarizes incidence rates of the 5 most common sexually transmitted infections (STIs) among active component service members of the U.S. Armed Forces during 2010–2018. Infections with chlamydia were the most common, followed in decreasing order of frequency by infections with genital human papillomavirus (HPV), gonorrhea, genital herpes ...

Article
Mar 1, 2019

Vasectomy and Vasectomy Reversals, Active Component, U.S. Armed Forces, 2000–2017

Sperm is the male reproductive cell  Photo: iStock

During 2000–2017, a total of 170,878 active component service members underwent a first-occurring vasectomy, for a crude overall incidence rate of 8.6 cases per 1,000 person-years (p-yrs). Among the men who underwent incident vasectomy, 2.2% had another vasectomy performed during the surveillance period. Compared to their respective counterparts, the ...

Article
Mar 1, 2019

Brief Report: Male Infertility, Active Component, U.S. Armed Forces, 2013–2017

Sperm is the male reproductive cell  Photo: iStock

Infertility, defined as the inability to achieve a successful pregnancy after 1 year or more of unprotected sexual intercourse or therapeutic donor insemination, affects approximately 15% of all couples. Male infertility is diagnosed when, after testing both partners, reproductive problems have been found in the male. A male factor contributes in part ...

Article
Mar 1, 2019

Testosterone Replacement Therapy Use Among Active Component Service Men, 2017

Image of Marines carrying a wooden log for physical fitness. Click to open a larger version of the image.

This analysis summarizes the prevalence of testosterone replacement therapy (TRT) during 2017 among active component service men by demographic and military characteristics. This analysis also determines the percentage of those receiving TRT in 2017 who had an indication for receiving TRT using the 2018 American Urological Association (AUA) clinical ...

Article
Feb 1, 2019

Update: Malaria, U.S. Armed Forces, 2018

Anopheles merus

Malaria infection remains an important health threat to U.S. service mem­bers who are located in endemic areas because of long-term duty assign­ments, participation in shorter-term contingency operations, or personal travel. In 2018, a total of 58 service members were diagnosed with or reported to have malaria. This represents a 65.7% increase from ...

Article
Feb 1, 2019

Update: Incidence of Glaucoma Diagnoses, Active Component, U.S. Armed Forces, 2013–2017

Glaucoma

Glaucoma is an eye disease that involves progressive optic nerve damage and vision loss, leading to blindness if undetected or untreated. This report describes an analysis using the Defense Medical Surveillance System to identify all active component service members with an incident diagnosis of glaucoma during the period between 2013 and 2017. The ...

Article
Feb 1, 2019

Outbreak of Acute Respiratory Illness Associated with Adenovirus Type 4 at the U.S. Naval Academy, 2016

Malaria case definition

Human adenoviruses (HAdVs) are known to cause respiratory illness outbreaks at basic military training (BMT) sites. HAdV type-4 and -7 vaccines are routinely administered at enlisted BMT sites, but not at military academies. During Aug.–Sept. 2016, U.S. Naval Academy clinical staff noted an increase in students presenting with acute respiratory ...

Article
Feb 1, 2019

Re-evaluation of the MSMR Case Definition for Incident Cases of Malaria

Anopheles merus

The MSMR has been publishing the results of surveillance studies of malaria since 1995. The standard MSMR case definition uses Medical Event Reports and records of hospitalizations in counting cases of malaria. This report summarizes the performance of the standard MSMR case definition in estimating incident cases of malaria from 2015 through 2017. ...

Article
Dec 1, 2018

Thyroid Disorders, Active Component, U.S. Armed Forces, 2008–2017

A U.S. naval officer listens through his stethoscope to hear his patient’s lungs at Camp Schwab in Okinawa, Japan in 2018. (Photo courtesy of U.S. Marine Corps) photo by Lance Cpl. Cameron Parks)

This analysis describes the incidence and prevalence of five thyroid disorders (goiter, thyrotoxicosis, primary/not otherwise specified [NOS] hypothyroidism, thyroiditis, and other disorders of the thyroid) among active component service members between 2008 and 2017. During the 10-year surveillance period, the most common incident thyroid disorder ...

Article
Dec 1, 2018

Incidence and Prevalence of the Metabolic Syndrome Using ICD-9 and ICD-10 Diagnostic Codes, Active Component, U.S. Armed Forces, 2002–2017

This report uses ICD-9 and ICD-10 codes (277.7 and E88.81, respectively) for the metabolic syndrome (MetS) to summarize trends in the incidence and prevalence of this condition among active component members of the U.S. Armed Forces between 2002 and 2017. During this period, the crude overall incidence rate of MetS was 7.5 cases per 100,000 person ...

Article
Dec 1, 2018

Adrenal Gland Disorders, Active Component, U.S. Armed Forces, 2002–2017

During 2002–2017, the most common incident adrenal gland disorder among male and female service members was adrenal insufficiency and the least common was adrenomedullary hyperfunction. Adrenal insufficiency was diagnosed among 267 females (crude overall incidence rate: 8.2 cases per 100,000 person-years [p-yrs]) and 729 males (3.9 per 100,000 p-yrs). ...

Fact Sheet
Mar 30, 2017

Demographic and Military Traits of Service Members Diagnosed as Traumatic Brain Injury Cases

.PDF | 283.00 KB

This fact sheet provides details on the demographic and military traits of service members diagnosed as traumatic brain injury (TBI) cases during a 16-year surveillance period from 2001 through 2016, a total of 276,858 active component service members received first-time diagnoses of TBI - a structural alteration of the brain or physiological ...

Fact Sheet
Mar 30, 2017

Rhabdomyolysis by Location, Active Component, U.S. Armed Forces, 2012-2016 Fact Sheet

.PDF | 313.80 KB

This fact sheet provides details on Rhabdomyolysis by location for active component, U.S. Armed Forces during a five-year surveillance period from 2012 through 2016. The medical treatment facilities at nine installations diagnosed at least 50 cases each and, together approximately half (49.9%) of all diagnosed cases.

Fact Sheet
Mar 30, 2017

Heat Illnesses by Location, Active Component, U.S. Armed Forces, 2012-2016 Fact Sheet

.PDF | 267.04 KB

This fact sheet provides details on heat illnesses by location during a five-year surveillance period from 2012 through 2016. 11,967 heat-related illnesses were diagnosed at more than 250 military installations and geographic locations worldwide. Three Army Installations accounted for close to one-third of all heat illnesses during the period.

Skip subpage navigation
Refine your search
Last Updated: July 11, 2023
Follow us on Instagram Follow us on LinkedIn Follow us on Facebook Follow us on X Follow us on YouTube Sign up on GovDelivery