Christopher Dunphy
Current Organizations / Institutes
The organizations/institutes from the scholar's latest article
Research Subjects
Christopher Dunphy has a total of 63 co-authors. Here are the top co-authors by number of shared publications:
- Cora Peterson
National Center for Injury Prevention and Control, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
3 shared publications Gabrielle F. Miller
Division of Injury Prevention, National Center for Injury Prevention and Control, Centers for Disease Control and Prevention (CDC), Atlanta, USA
3 shared publications- Gabrielle F. Miller
National Center for Injury Prevention and Control, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
3 shared publications - Gregory Sunshine
CDC COVID-19 Response, Monitoring and Evaluation Team (Mss Ajiboye, Howard-Williams, Vo, and Weber, Mr McCord, Mr Sunshine, Drs Dunphy, Ladva, and Robinson), Office of Public Health Law Services (Mr Sunshine), and Division of Global HIV & TB, Global Health Center (Ms Ajiboye), Centers for Disease Control and Prevention, Atlanta, GA and Environmental and Occupational Health, School of Public Health (Mr Gakh), University of Nevada, Las Vegas, Nevada
3 shared publications Kun Zhang
National Center for Injury Prevention and Control, Centers for Disease Control and Prevention, Atlanta, Georgia
3 shared publicationsCandace Girod
Division of Injury Prevention, National Center for Injury Prevention and Control, Centers for Disease Control and Prevention (CDC), Atlanta, USA
2 shared publications
Latest Publications
- 14 February 2026
- Published by Elsevier in American Journal of Preventive Medicine
- Vol. 71 (2) , 108322
Mental Health Diagnosis and Costs After Unintentional Injuries and Assaults
- 14 February 2026
- Published by Elsevier in American Journal of Preventive Medicine
- Vol. 71 (2) , 108322
Mental Health Diagnosis and Costs After Unintentional Injuries and Assaults
- 1 December 2025
- Published by Elsevier in American Journal of Preventive Medicine
- Vol. 70 (4) , 108208
Association Between Health Plan Design and the Demand for Naloxone: Evidence From a Natural Experiment in New York
- 1 December 2025
- Published by Elsevier in American Journal of Preventive Medicine
- Vol. 70 (4) , 108208
Association Between Health Plan Design and the Demand for Naloxone: Evidence From a Natural Experiment in New York
- 18 October 2024
- Published by BMJ in Injury Prevention
- Vol. 32 (3) , 408-414
Rates of fall injuries across three claims databases, 2019
Introduction In 2021, among all age groups, falls ranked as the third leading cause of unintentional injury death in the USA. Unlike fatal data, which rely on death certificates as the gold standard, there is not a gold standard for non-fatal data. Non-fatal falls data are often based on insurance claims or administrative billing data. The purpose of our study is to compare three claims databases to estimate rates of unintentional fall-related hospitalisations in 2019, the most recent year of available data across the three sources. Methods Three databases were used to produce incidence rates of fall-related hospitalisations for the year 2019: (1) Merative MarketScan research databases, (2) Centers for Medicare and Medicaid Services (CMS) data and (3) Healthcare Cost and Utilization Project (HCUP) National Inpatient Sample. Inpatient falls were identified using International Classification of Diseases, 10th Revision, Clinical Modification codes. Incidence rates per 100 000 people were then produced across all three datasets by payer type. Unadjusted incidence rate ratios were estimated with corresponding 95% CIs. Results There were wide disparities among fall rates between the three datasets by payer type. HCUP had the highest rate of falls among Medicare (1087.6 per 100 000) and commercial enrollees (74.7 per 100 000), while CMS had the highest rates of falls among Medicaid enrollees (148.0 per 100 000). Conclusions This study shows wide variation in fall hospitalisation rates based on the claims data used to estimate rates. This study suggests that database selection is an important consideration when determining incidence of non-fatal falls.
- 18 October 2024
- Published by BMJ in Injury Prevention
- Vol. 32 (3) , 408-414
Rates of fall injuries across three claims databases, 2019
Introduction In 2021, among all age groups, falls ranked as the third leading cause of unintentional injury death in the USA. Unlike fatal data, which rely on death certificates as the gold standard, there is not a gold standard for non-fatal data. Non-fatal falls data are often based on insurance claims or administrative billing data. The purpose of our study is to compare three claims databases to estimate rates of unintentional fall-related hospitalisations in 2019, the most recent year of available data across the three sources. Methods Three databases were used to produce incidence rates of fall-related hospitalisations for the year 2019: (1) Merative MarketScan research databases, (2) Centers for Medicare and Medicaid Services (CMS) data and (3) Healthcare Cost and Utilization Project (HCUP) National Inpatient Sample. Inpatient falls were identified using International Classification of Diseases, 10th Revision, Clinical Modification codes. Incidence rates per 100 000 people were then produced across all three datasets by payer type. Unadjusted incidence rate ratios were estimated with corresponding 95% CIs. Results There were wide disparities among fall rates between the three datasets by payer type. HCUP had the highest rate of falls among Medicare (1087.6 per 100 000) and commercial enrollees (74.7 per 100 000), while CMS had the highest rates of falls among Medicaid enrollees (148.0 per 100 000). Conclusions This study shows wide variation in fall hospitalisation rates based on the claims data used to estimate rates. This study suggests that database selection is an important consideration when determining incidence of non-fatal falls.
- 3 September 2024
- Published by Wolters Kluwer Health in Journal of Public Health Management & Practice
- Vol. 30 (6) , E335-E343
Changes in Self-Reported Mask Use After the Lifting of State-Issued Mask Mandates in 20 US States, February–June 2021
Objective: In April 2020, the US Centers for Disease Control and Prevention (CDC) recommended community masking to prevent the transmission of SARS-CoV-2. Since then, a total of 39 US states and DC issued mask mandates. Despite CDC recommendations and supporting evidence that masking reduces COVID-19 community transmission, from January to June 20, 2021 states lifted their mask mandates for all individuals. This study examined the association between lifting state-issued mask mandates and mask-wearing behavior in 2021. Design: We estimated a difference-in-difference model, comparing changes in the likelihood for individuals to wear a mask in states that lifted their mask mandate relative to states that kept their mandates in place between February and June of 2021. Setting: Individuals were surveyed from across the United States. Participants: We used masking behavior data collected by the Porter Novelli View 360 + national surveys (N = 3459), and data from state-issued mask mandates obtained by CDC and the University of Nevada, Las Vegas. Main Outcomes: The outcome variable of interest was self-reported mask use during the 30 days prior to the survey data collection. Results: In the overall population, lifting mask mandates did not significantly influence mask-wearing behavior. Mask wearing did significantly decrease in response to the lifting of mask mandates among individuals living in rural counties and individuals who had not yet decided whether they would receive a COVID-19 vaccine. Conclusion: Policies around COVID-19 behavioral mitigation, specifically amongst those unsure about vaccination and in rural areas, may help reduce the transmission of COVID-19 and other respiratory viruses, especially in communities with low vaccination rates.
- 3 September 2024
- Published by Wolters Kluwer Health in Journal of Public Health Management & Practice
- Vol. 30 (6) , E335-E343
Changes in Self-Reported Mask Use After the Lifting of State-Issued Mask Mandates in 20 US States, February–June 2021
Objective: In April 2020, the US Centers for Disease Control and Prevention (CDC) recommended community masking to prevent the transmission of SARS-CoV-2. Since then, a total of 39 US states and DC issued mask mandates. Despite CDC recommendations and supporting evidence that masking reduces COVID-19 community transmission, from January to June 20, 2021 states lifted their mask mandates for all individuals. This study examined the association between lifting state-issued mask mandates and mask-wearing behavior in 2021. Design: We estimated a difference-in-difference model, comparing changes in the likelihood for individuals to wear a mask in states that lifted their mask mandate relative to states that kept their mandates in place between February and June of 2021. Setting: Individuals were surveyed from across the United States. Participants: We used masking behavior data collected by the Porter Novelli View 360 + national surveys (N = 3459), and data from state-issued mask mandates obtained by CDC and the University of Nevada, Las Vegas. Main Outcomes: The outcome variable of interest was self-reported mask use during the 30 days prior to the survey data collection. Results: In the overall population, lifting mask mandates did not significantly influence mask-wearing behavior. Mask wearing did significantly decrease in response to the lifting of mask mandates among individuals living in rural counties and individuals who had not yet decided whether they would receive a COVID-19 vaccine. Conclusion: Policies around COVID-19 behavioral mitigation, specifically amongst those unsure about vaccination and in rural areas, may help reduce the transmission of COVID-19 and other respiratory viruses, especially in communities with low vaccination rates.
- 3 September 2024
- Published by BMJ in Injury Prevention
- Vol. 32 (3) , 384-390
Association between state minimum wage and firearm suicides in the USA, 2000–2020
Background Firearm suicides constitute a major public health issue. Policies that enhance economic security and decrease community-level poverty may be effective strategies for reducing risk of firearm suicide. This study examined the association between state minimum wage and firearm suicide. Methods State minimum wage, obtained from Temple’s Law Atlas and augmented by legal research, was conceptualised using the modified Kaitz Index and a continuous variable centred on the federal minimum wage. State-level suicide counts were obtained from 2000 to 2020 multiple-cause-of-death mortality data from the National Vital Statistics System. Log-linear regressions were conducted to model the associations between state minimum wage and firearm suicides, stratifying by demographic groups. Analyses were conducted in 2023. Results A one percentage point increase in a state’s modified Kaitz Index was associated with a 0.3% (95% CI −0.6% to –0.0%) decrease in firearm suicides within a state. A US$1.00 increase in a state’s minimum wage above the federal minimum wage was associated with a 1.4% (95% CI −2.1% to –0.6%) decrease in firearm suicides. When stratified by quartile of firearm ownership, the modified Kaitz Index was associated with decreases in firearm suicides most consistently in the two lowest quartiles. Conclusion Increasing a state’s minimum wage may be a policy option to consider as part of a comprehensive approach to reducing firearm suicides. These findings expand the evidence base for how economic policies may be leveraged to reduce firearm suicides.
- 3 September 2024
- Published by BMJ in Injury Prevention
- Vol. 32 (3) , 384-390
Association between state minimum wage and firearm suicides in the USA, 2000–2020
Background Firearm suicides constitute a major public health issue. Policies that enhance economic security and decrease community-level poverty may be effective strategies for reducing risk of firearm suicide. This study examined the association between state minimum wage and firearm suicide. Methods State minimum wage, obtained from Temple’s Law Atlas and augmented by legal research, was conceptualised using the modified Kaitz Index and a continuous variable centred on the federal minimum wage. State-level suicide counts were obtained from 2000 to 2020 multiple-cause-of-death mortality data from the National Vital Statistics System. Log-linear regressions were conducted to model the associations between state minimum wage and firearm suicides, stratifying by demographic groups. Analyses were conducted in 2023. Results A one percentage point increase in a state’s modified Kaitz Index was associated with a 0.3% (95% CI −0.6% to –0.0%) decrease in firearm suicides within a state. A US$1.00 increase in a state’s minimum wage above the federal minimum wage was associated with a 1.4% (95% CI −2.1% to –0.6%) decrease in firearm suicides. When stratified by quartile of firearm ownership, the modified Kaitz Index was associated with decreases in firearm suicides most consistently in the two lowest quartiles. Conclusion Increasing a state’s minimum wage may be a policy option to consider as part of a comprehensive approach to reducing firearm suicides. These findings expand the evidence base for how economic policies may be leveraged to reduce firearm suicides.
- Open Access
- 21 July 2024
- Published by BMJ in Injury Prevention
- Vol. 31 (4) , 333-339
Medical and work loss costs of violence, self-harm, unintentional and traumatic brain injuries per injured person in the USA
Objective Injuries and poisoning are leading causes of US morbidity and mortality. This study aimed to update medical and work loss cost estimates per injured person. Methods Injuries treated in emergency departments (ED) during 2019–2020 were analysed in terms of mechanism (eg, fall) and intent (eg, unintentional), as well as traumatic brain injury (TBI) (multiple mechanisms and intents). Fatal injury medical spending was based on the Nationwide Emergency Department Sample and National Inpatient Sample. Non-fatal injury medical spending and workplace absences (general, short-term disability and workers’ compensation) were analysed among injury patients with commercial insurance or Medicaid and matched controls during the year following an injury ED visit using MarketScan databases. Results Medical spending for injury deaths in hospital EDs and inpatient settings averaged US$4777 (n=57 296) and US$45 678 per fatality (n=89 175) (2020 USD). Estimates for fatal TBI were US$5052 (n=5363) and US$47 952 (n=37 184). People with ED treat and release visits for non-fatal injuries had on average US$5798 (n=895 918) in attributable medical spending and US$1686 (11 missed days) (n=116 836) in work loss costs during the following year, while people with non-fatal injuries who required hospitalisation after an ED injury visit had US$52 246 (n=32 976) in medical spending and US$7815 (51 days) (n=4473) in work loss costs. Estimates for non-fatal TBI were US$4529 (n=25 792), US$1503 (10 days) (n=1631), US$51 241 (n=3030) and US$6110 (40 days) (n=246). Conclusions and relevance Per person costs of injuries and violence are important to monitor the economic burden of injuries and assess the value of prevention strategies.
- 21 July 2024
- Published by BMJ in Injury Prevention
- Vol. 31 (4) , 333-339
Open AccessMedical and work loss costs of violence, self-harm, unintentional and traumatic brain injuries per injured person in the USA
Objective Injuries and poisoning are leading causes of US morbidity and mortality. This study aimed to update medical and work loss cost estimates per injured person. Methods Injuries treated in emergency departments (ED) during 2019–2020 were analysed in terms of mechanism (eg, fall) and intent (eg, unintentional), as well as traumatic brain injury (TBI) (multiple mechanisms and intents). Fatal injury medical spending was based on the Nationwide Emergency Department Sample and National Inpatient Sample. Non-fatal injury medical spending and workplace absences (general, short-term disability and workers’ compensation) were analysed among injury patients with commercial insurance or Medicaid and matched controls during the year following an injury ED visit using MarketScan databases. Results Medical spending for injury deaths in hospital EDs and inpatient settings averaged US$4777 (n=57 296) and US$45 678 per fatality (n=89 175) (2020 USD). Estimates for fatal TBI were US$5052 (n=5363) and US$47 952 (n=37 184). People with ED treat and release visits for non-fatal injuries had on average US$5798 (n=895 918) in attributable medical spending and US$1686 (11 missed days) (n=116 836) in work loss costs during the following year, while people with non-fatal injuries who required hospitalisation after an ED injury visit had US$52 246 (n=32 976) in medical spending and US$7815 (51 days) (n=4473) in work loss costs. Estimates for non-fatal TBI were US$4529 (n=25 792), US$1503 (10 days) (n=1631), US$51 241 (n=3030) and US$6110 (40 days) (n=246). Conclusions and relevance Per person costs of injuries and violence are important to monitor the economic burden of injuries and assess the value of prevention strategies.
- 23 May 2024
- Published by SAGE Publications in Public Health Reports®
- Vol. 139 (6) , 750-759
Changes in State Laws on Suicide Prevention Training for School Staff, 2002-2022
Objectives: Youth suicide is an urgent public health problem. Gatekeeper training aims to prevent suicide by training people to identify warning signs and make referrals to appropriate services. Many states in the United States have enacted gatekeeper training laws (GTLs) to train school staff in suicide prevention. The objectives of this study were to describe the development of a dataset on GTLs and use the dataset to summarize trends in uptake of GTLs from 2002 through 2022 as well as differences in characteristics (eg, frequency and duration of training) of GTLs. Methods: We used publicly available legal databases from all 50 states and the District of Columbia to conduct a policy surveillance assessment of GTLs. We cross-checked data with the American Foundation for Suicide Prevention’s 2022 Suicide Prevention in Schools (K-12) issue brief and used Westlaw Edge to conduct a sensitivity analysis. We included the following data in the full dataset: type of laws (encouraged, mandatory, or conditional mandatory), date passed, effective date, frequency of training, and length of training. Results: In 2022, 49 states and the District of Columbia had GTLs, 31 of which were mandatory laws. In 2002, only 6 states had such laws, and none were mandatory. Conclusion: The growing proliferation of laws on suicide prevention training for school staff warrants evaluation of the laws’ effectiveness. Our policy surveillance data may be used to better understand the role of these laws in a school-based approach to youth suicide prevention.
- 23 May 2024
- Published by SAGE Publications in Public Health Reports®
- Vol. 139 (6) , 750-759
Changes in State Laws on Suicide Prevention Training for School Staff, 2002-2022
Objectives: Youth suicide is an urgent public health problem. Gatekeeper training aims to prevent suicide by training people to identify warning signs and make referrals to appropriate services. Many states in the United States have enacted gatekeeper training laws (GTLs) to train school staff in suicide prevention. The objectives of this study were to describe the development of a dataset on GTLs and use the dataset to summarize trends in uptake of GTLs from 2002 through 2022 as well as differences in characteristics (eg, frequency and duration of training) of GTLs. Methods: We used publicly available legal databases from all 50 states and the District of Columbia to conduct a policy surveillance assessment of GTLs. We cross-checked data with the American Foundation for Suicide Prevention’s 2022 Suicide Prevention in Schools (K-12) issue brief and used Westlaw Edge to conduct a sensitivity analysis. We included the following data in the full dataset: type of laws (encouraged, mandatory, or conditional mandatory), date passed, effective date, frequency of training, and length of training. Results: In 2022, 49 states and the District of Columbia had GTLs, 31 of which were mandatory laws. In 2002, only 6 states had such laws, and none were mandatory. Conclusion: The growing proliferation of laws on suicide prevention training for school staff warrants evaluation of the laws’ effectiveness. Our policy surveillance data may be used to better understand the role of these laws in a school-based approach to youth suicide prevention.
- 2 February 2024
- Published by Elsevier in American Journal of Preventive Medicine
- Vol. 66 (6) , 963-970
The Association Between State Minimum Wage and Firearm Homicides, 2000–2020
- 2 February 2024
- Published by Elsevier in American Journal of Preventive Medicine
- Vol. 66 (6) , 963-970
The Association Between State Minimum Wage and Firearm Homicides, 2000–2020
- 23 September 2022
- Published by Wolters Kluwer Health in Journal of Public Health Management & Practice
- Vol. 28 (6) , 712-719
The Association Between State-Issued Mask Mandates and County COVID-19 Hospitalization Rates
Context: Mask mandates are one form of nonpharmaceutical intervention that has been utilized to combat the spread of SARS-CoV2, the virus that causes COVID-19. Objective: This study examines the association between state-issued mask mandates and changes in county-level and hospital referral region (HRR)–level COVID-19 hospitalizations across the United States. Design: Difference-in-difference and event study models were estimated to examine the association between state-issued mask mandates and COVID-19 hospitalization outcomes. Participants: All analyses were conducted with US county-level data. Interventions: State-issued mask mandates. County-level data on the mandates were collected from executive orders identified on state government Web sites from April 1, 2020, to December 31, 2020. Main Outcome Measures: Daily county-level (and HRR-level) estimates of inpatient beds occupied by patients with confirmed or suspected COVID-19 were collected by the US Department of Health and Human Services. Results: The state issuing of mask mandates was associated with an average of 3.6 fewer daily COVID-19 hospitalizations per 100 000 people (P < .05) and a 1.2-percentage-point decrease in the percentage of county beds occupied with COVID-19 patients (P < .05) within 70 days of taking effect. Event study results suggest that this association increased the longer mask mandates were in effect. In addition, the results were robust to analyses conducted at the HRR level. Conclusions: This study demonstrated that state-issued mask mandates were associated with reduction in COVID-19 hospitalizations across the United States during the earlier portion of the pandemic. As new variants of the virus cause spikes in COVID-19 cases, reimposing mask mandates in indoor and congested public areas, as part of a layered approach to community mitigation, may reduce the spread of COVID-19 and lessen the burden on our health care system.
- 23 September 2022
- Published by Wolters Kluwer Health in Journal of Public Health Management & Practice
- Vol. 28 (6) , 712-719
The Association Between State-Issued Mask Mandates and County COVID-19 Hospitalization Rates
Context: Mask mandates are one form of nonpharmaceutical intervention that has been utilized to combat the spread of SARS-CoV2, the virus that causes COVID-19. Objective: This study examines the association between state-issued mask mandates and changes in county-level and hospital referral region (HRR)–level COVID-19 hospitalizations across the United States. Design: Difference-in-difference and event study models were estimated to examine the association between state-issued mask mandates and COVID-19 hospitalization outcomes. Participants: All analyses were conducted with US county-level data. Interventions: State-issued mask mandates. County-level data on the mandates were collected from executive orders identified on state government Web sites from April 1, 2020, to December 31, 2020. Main Outcome Measures: Daily county-level (and HRR-level) estimates of inpatient beds occupied by patients with confirmed or suspected COVID-19 were collected by the US Department of Health and Human Services. Results: The state issuing of mask mandates was associated with an average of 3.6 fewer daily COVID-19 hospitalizations per 100 000 people (P < .05) and a 1.2-percentage-point decrease in the percentage of county beds occupied with COVID-19 patients (P < .05) within 70 days of taking effect. Event study results suggest that this association increased the longer mask mandates were in effect. In addition, the results were robust to analyses conducted at the HRR level. Conclusions: This study demonstrated that state-issued mask mandates were associated with reduction in COVID-19 hospitalizations across the United States during the earlier portion of the pandemic. As new variants of the virus cause spikes in COVID-19 cases, reimposing mask mandates in indoor and congested public areas, as part of a layered approach to community mitigation, may reduce the spread of COVID-19 and lessen the burden on our health care system.