Comparative analysis of injury identification using KABCO and ISS in linked North Carolina trauma registry and crash data.

OBJECTIVE: The purpose of this study was to examine differences between police-reported injury severity and trauma registry data among persons with linked records in North Carolina and quantify the degree of alignment. METHODS: We analyzed linked North Carolina trauma registry and motor vehicle crash data from 2018. Injury severity identification was assessed using police-reported 5-point scale KABCO from crash data and Injury Severity Score (ISS) from trauma records. The analysis was stratified by age, sex/gender, race, ethnicity, and road users type to examine differences across groups. We calculated sensitivity, specificity, positive predictive values, and negative predictive values between police-reported injury severity and trauma registry data using ISS as the gold standard. RESULTS: A higher proportion of patients were classified as suspected minor injuries (39.0%) compared to moderate injuries in trauma registry (25.1%). Police-reported crash data underreported injury severity when compared to trauma registry data. Police-reported KABCO had a higher degree of specificity when classifying minor injuries (79.3%) but substantially underestimated seriously injured patients, with a sensitivity of 49.9%. These findings were also consistent when stratified by subpopulations. CONCLUSION: Hospital-based motor vehicle crash data are a main source of injury severity identification for road safety. Police-reported data were relatively accurate for minor injuries but not seriously injured patients. Understanding the characteristics of each data source both separately and linked will be critical for problem identification and program development to move toward a safe transportation system for all road users.

Racial and ethnic disparities in motor vehicle crash-related outcomes in North Carolina surrounding the COVID-19 pandemic.

Long-term impacts of the COVID-19 pandemic on racial and ethnic disparities in motor vehicle crash (MVC) injuries and death are poorly understood. This study aimed to characterize trends and investigate the heterogeneity of MVC-related disparities in North Carolina across several data sources. Crash reports, emergency department visit records, and death certificates from 2018 to 2021 were used to calculate monthly population-rates of MVC-related public health outcomes. We estimated trendlines using joinpoint regression and compared outcomes across racial and ethnic classifications. MVC and MVC-related injury rates declined in conjunction with NC's stay-at-home order, while rates of severe outcomes remained unimpacted. By December 2021 rates of MVC-related outcomes met or exceeded pre-pandemic levels, with the highest rates observed among non-Hispanic Black individuals. Racial and ethnic disparities in MVC-related outcomes remained prevalent throughout the COVID-19 pandemic. These results highlight the importance of a holistic approach to traffic injury surveillance when assessing the impact of MVCs.

Feasibility of linking violent death decedents to prior-month emergency department visits in North Carolina, 2019-2020.

OBJECTIVE: Linking data between violent death decedents and other sources can provide valuable insight, highlighting opportunities for prevention of violent injury. This study investigated the feasibility of linking North Carolina Violent Death Reporting System (NC-VDRS) records with North Carolina Disease Event Tracking and Epidemiologic Collection Tool (NC DETECT) emergency department (ED) visit data to identify prior-month ED visits among this population. METHODS: NC-VDRS death records from 2019 through 2020 were linked to NC DETECT ED visit data from December 2018 through 2020 using a probabilistic linkage approach. Linkage variables included date of birth, age, sex, zip code and county of residence, date of event (death/ED visit) and mechanism of injury. Potential linkable ED visits were filtered to those occurring in the month prior to death and manually reviewed for validity. Linked records were compared with the NC-VDRS study population to assess linkage performance and generalisability. RESULTS: Among the 4768 violent deaths identified, we linked 1340 NC-VDRS records to at least one ED visit in the month prior to death. A higher proportion of decedents dying in medical facilities (ED/outpatient, hospital inpatient, hospice or nursing/long-term care facility) linked to a prior-month visit (80%) relative to those dying in other locations (12%). When stratified by place of death, linked decedents demographically resembled the overall NC-VDRS study population. CONCLUSIONS: Though resource intensive, an NC-VDRS-to-NC DETECT linkage was successful in identifying prior-month ED visits among violent death decedents. This linkage should be leveraged to further analyse ED utilisation prior to violent death, expanding the knowledge base surrounding prevention opportunities for violent injuries.

Structural Racism and Pedestrian Safety: Measuring the Association Between Historical Redlining and Contemporary Pedestrian Fatalities Across the United States, 2010‒2019.

Objectives. To examine the association between historical redlining and contemporary pedestrian fatalities across the United States. Methods. We analyzed 2010-2019 traffic fatality data, obtained from the Fatality Analysis Reporting System, for all US pedestrian fatalities linked by location of crash to 1930s Home Owners' Loan Corporation (HOLC) grades and current sociodemographic factors at the census tract level. We applied generalized estimating equation models to assess the relationship between the count of pedestrian fatalities and redlining. Results. In an adjusted multivariable analysis, tracts graded D ("Hazardous") had a 2.60 (95% confidence interval = 2.26, 2.99) incidence rate ratio (per residential population) of pedestrian fatalities compared with tracts graded A ("Best"). We found a significant dose‒response relationship: as grades worsened from A to D, rates of pedestrian fatalities increased. Conclusions. Historical redlining policy, initiated in the 1930s, has an impact on present-day transportation inequities in the United States. Public Health Implications. To reduce transportation inequities, understanding how structurally racist policies, past and present, have an impact on community-level investments in transportation and health is crucial. (Am J Public Health. 2023;113(4):420-428. https://doi.org/10.2105/AJPH.2022.307192).

Database selection matters: A case study in child restraint use and injury patterns using North Carolina motor vehicle traffic crash report and trauma registry data.

OBJECTIVE: While proper restraint use is protective against motor traffic vehicle crash (MVTC)-associated morbidity and mortality, it is inconsistently measured across health and MVTC data sources. This project addresses this gap by assessing differences in child restraint measures between two North Carolina (NC) datasets and comparing the utility of these sources to evaluate patterns of child restraint use and associated health outcomes. METHODS: We analyzed 2018 NC MVTC and NC Trauma Registry (NCTR) data for children ≤15 years old, both separately and as linked MVTC-NCTR records. We calculated mean and standard deviation for continuous variables and frequency and proportion for categorical variables. Among linked records, we compared reported restraint use and performed age-adjusted logistic regression to estimate associations between restraint use and severe injury. RESULTS: A lower proportion of pediatric MVTC victims were reported as unrestrained in the MVTC (14.7%) versus NCTR (25.8%) data. Among linked MVTC-NCTR records, only 41.3% featured perfect concordance of restraint information between datasets. Among linked records, child restraint was reported for 31.3% of children, while the NCTR data allowed more granular coding of child restraint (30.3% overall), including child booster seat (13.5%), child car seat (8.7%), infant car seat (4.8%), and unrestrained in child car seat (3.4%). Age-adjusted regression analyses of the linked data revealed that lap/shoulder seatbelt use was significantly associated with lower likelihood of severe injury compared to being unrestrained whether informed by MVTC (OR = 0.39; 95% CI: 0.16, 0.93) or NCTR (OR = 0.38; 95% CI: 0.15, 0.96) data. While the association between reported use of a child car seat and severe injury was not statistically significant in the MVTC data (OR = 0.50; 95% CI: 0.19, 1.32), child car seat use reported in the NCTR data revealed a significant association (OR = 0.16; 95% CI: 0.03, 0.93). CONCLUSIONS: Linked crash and trauma center data allow for identifying important patterns of restraint use among pediatric passengers in MVTCs. Dataset-dependent differences in measuring restraint use have critical public health implications and illustrate the importance of careful dataset selection prior to analysis, as the use of different data sources may impact overall study conclusions.

Examining the Effect of Pedestrian Crashes on Vulnerable Populations in North Carolina.

BACKGROUND: Over the last several years, pedestrian fatalities have increased in North Carolina; however, fatalities represent a small proportion of the total number of nonfatally injured pedestrians. Therefore, we linked statewide motor vehicle crash (MVC) and emergency department (ED) visit data to better understand the circumstances and characteristics of pedestrians treated in North Carolina emergency departments (EDs) for injuries related to crashes. METHODS: We linked information for pedestrians and bicyclists from 2017 North Carolina police-reported MVCs to population-based ED visit data using hierarchical deterministic methods. RESULTS: We linked 45% of pedestrian crash records to ED visit records (N = 1383 incident ED visits). The rate of pedestrians treated in North Carolina EDs for their injuries was 13.6 ED visits per 100,000 person years. For pedestrian injuries treated in North Carolina EDs, rates (per 100,000 person years in parentheses) were higher among men (15.5) and Black pedestrians (22.7) than women (10.6) and White pedestrians (8.2). Sociodemographic characteristics associated with serious injuries included age, sex, race/ethnicity, and expected source of payment for the ED visit. Crash characteristics associated with serious injuries included posted speed limit, ambient light, number of lanes, and striking vehicle type. LIMITATIONS: The study involved the use of secondary data, not collected specifically for pedestrian injury surveillance. CONCLUSIONS: Pedestrian injuries and fatalities place a considerable burden on the population of North Carolina, especially among persons of color and older adults. Injury prevention programs are actively addressing this problem, but more needs to be done.

The impact of the COVID-19 pandemic on the utilization of emergency department services for the treatment of injuries.

CONTEXT: The global COVID-19 pandemic has had a major impact on the utilization of healthcare services; however, the impact on population-level emergency department (ED) utilization patterns for the treatment of acute injuries has not been fully characterized. OBJECTIVE: This study examined the frequency of North Carolina (NC) EDs visits for selected injury mechanisms during the first eleven months of the COVID-19 pandemic. METHODS: Data were obtained from the NC Disease Event Tracking and Epidemiologic Collection Tool (NC DETECT), NC's legislatively mandated statewide syndromic surveillance system for the years 2019 and 2020. Frequencies of January - November 2020 NC ED visits were compared to frequencies of 2019 visits for selected injury mechanisms, classified according to International Classification of Diseases, 10th Revision, Clinical Modification (ICD-10-CM) injury diagnosis and mechanism codes. RESULTS: In 2020, the total number of injury-related visits declined by 19.5% (N = 651,158) as compared to 2019 (N = 809,095). Visits related to motor vehicle traffic crashes declined by a greater percentage (29%) and falls (19%) declined by a comparable percentage to total injury-related visits. Visits related to assault (15%) and self-harm (10%) declined by smaller percentages. Medication/drug overdose visits increased (10%), the only injury mechanism studied to increase during this period. CONCLUSION: Both ED avoidance and decreased exposures may have contributed to these declines, creating implications for injury morbidity and mortality. Injury outcomes exacerbated by the pandemic should be addressed by timely public health responses.

Selected characteristics and injury patterns by age group among pedestrians treated in North Carolina emergency departments.

OBJECTIVE: The objective of this study was to describe pedestrian demographic characteristics, crash characteristics, selected health outcomes, and injury patterns by age using linked North Carolina (NC) crash-emergency department (ED) visit data for the period October 1, 2010, to September 30, 2015. METHODS: This was a descriptive epidemiologic study. To examine both crash and health outcomes, NC pedestrian crash records were linked to statewide NC ED visit records using hierarchical deterministic methods. Pearson chi-square tests were used to compare the frequencies of pedestrians treated in NC EDs by sex, race/ethnicity, crash location, rurality, estimated driver speed at impact, ambient light, hospitalization/death, location of injury, and nature of injury, stratified by the following age groups: 0-14, 15-24, 25-64, and ≥65 years. RESULTS: Most pedestrians treated in NC EDs were male (57.5%), except among adults ≥65 years old (47.5%). Over half of all injured pedestrians aged 0-14 (52.6%) and 15-24 (50.5%) years were Black/African American, and 70.8% of injured pedestrians ≥65 years were white. Among pedestrians aged 25-64 years, no single racial/ethnic group was the majority. Though most pedestrians were injured on trafficways (71.7%) and at speeds ≤35 mph (80.1%), adults ≥65 years were less likely to be involved in on-trafficway crashes (51.0%) and pedestrians aged 15-24 years were more likely to be involved in >35 mph crashes (22.9%) compared to other age groups. Most pedestrians were injured under daylight conditions (56.9%). Regarding selected health outcomes, the highest frequency of hospitalization/death was for pedestrians aged ≥65 years (26.3%), compared to those aged 0-14 years (18.8%) and 15-64 years (12.4%). In terms of location of injury, 0- to 14-year-olds had the highest proportion of head injuries (39.5%), and adults ≥65 years of age had the highest proportion of spinal column/vertebral column (12.6%) and upper extremity injuries (33.2%). For nature of injury, 0- to 14-year-olds had the highest proportion of traumatic brain injuries (11.4%) and superficial wounds and contusions (62.8%). Adults aged ≥65 years had the highest proportion of open wounds/amputations and fractures (16.1%). Adults aged 25-64 years had the highest proportion of strains/sprains/dislocations (18.7%). CONCLUSIONS: There were considerable differences in demographic characteristics, crash characteristics, frequency of hospitalization/death, and injury patterns by age group. It is important to design streets and implement transportation policies and programs that improve safety for all pedestrians.

Begin risk assessment for falls in women at 45, not 65.

The clinical and epidemiological literature provides guidelines for fall prevention starting at age 65; however, the focus on age ≥65 is not evidence based. Therefore, this study examined state-wide North Carolina emergency department visit data to examine the characteristics of falls across the age spectrum, identify the age at which the incidence of fall-related emergency department visits started to increase and determine whether these trends were similar for men and women. We determined that incidence rates of fall-related emergency department visits began to increase in early middle age, particularly for women. Since fall risk assessment and prevention activities should be initiated prior to an injurious fall, we recommend beginning these activities before age 65.

Characteristics of sports and recreation-related emergency department visits among school-age children and youth in North Carolina, 2010-2014.

BACKGROUND: Sports and recreational activities are an important cause of injury among children and youth, with sports-related traumatic brain injuries (TBIs) being of particular concern given the developing brain. This paper reports the characteristics of sport and recreation-related (SR) emergency department (ED) visits among school-age children and youth in a statewide population. METHODS: This study included all injury-related visits made to all North Carolina 24/7 acute-care civilian hospital-affiliated EDs by school-age youth, 5-18 years of age, during 2010-2014 (N = 918,662). Population estimates were based on US decennial census data. Poisson regression methods were used to estimate incidence rates and rate ratios. RESULTS: During the five-year period, there were 767,075 unintentional injury-related ED visits among school-age youth, of which 213,518 (27.8%) were identified as SR injuries. The average annual absolute number and incidence rate (IR) of SR ED visits among school-age youth was 42,704 and 2374.5 ED visits per 100,000 person-years (95% confidence interval [CI], 2364.4-2384.6), respectively. In comparison to other unintentional injuries among school-age youth, SR ED visits were more likely to be diagnosed with an injury to the upper extremity (Injury Proportion Ratio [IPR] = 1.28; 95% CI, 1.27-1.29), the lower extremity (IPR = 1.14; 95% CI, 1.13-1.15), and a TBI or other head/neck/facial injury (IPR = 1.12; 95% CI, 1.11-1.13). Among ED visits made by school-age youth, the leading cause of SR injury was sports/athletics played as a group or team. The leading cause of team sports/athletics injury was American tackle football among boys and soccer among girls. The proportion of ED visits diagnosed with a TBI varied by age and sex, with 15-18 year-olds and boys having the highest population-based rates. CONCLUSIONS: Sports and recreational activities are an important component of a healthy lifestyle, but they are also a major source of injury morbidity among school-age youth. Physical activity interventions should take into account sex and age differences in SR injury risk.

Snakebites Treated in North Carolina Emergency Departments, October 2013-September 2015.

INTRODUCTION: North Carolina (NC) is home to more than 30 species of indigenous venomous and nonvenomous snakes. Snakebites can cause debilitating and potentially fatal injuries. However, there is a lack of current information available describing the incidence of snakebites in NC. Therefore, we performed this study of snakebites treated in NC emergency departments (EDs) using the statewide syndromic surveillance system, the North Carolina Disease Event Tracking and Epidemiologic Collection Tool (NC DETECT). METHODS: This was a descriptive epidemiologic study characterizing NC ED visits collected by NC DETECT between October 1, 2013 and September 30, 2015 with an assigned International Classification of Diseases, 9th Revision, Clinical Modification code or keyword indicating a snakebite. RESULTS: Over the 2-year period, the absolute count of snakebite-related ED visits was 2080 visits with an incidence rate of 10.4 visits per 100 000 person-years (95% confidence interval: 10.0-10.9). The frequency of snakebite was highest during the summer months and evening hours. Men had higher incidence rates of snakebite-related ED visits than women, and residents of the Coastal Plain geographic region of NC had higher incidence rates than persons in other regions. CONCLUSIONS: The current study indicated that snakebites are common injuries treated at NC EDs, with a strong seasonal and geographic component. Additional research is needed to further characterize the circumstances associated with snakebites for the development of preventive measures and public health education.

Use of syndromic surveillance data to monitor poisonings and drug overdoses in state and local public health agencies.

BACKGROUND: The incidence of poisoning and drug overdose has risen rapidly in the USA over the last 16 years. To inform local intervention approaches, local health departments (LHDs) in North Carolina (NC) are using a statewide syndromic surveillance system that provides timely, local emergency department (ED) and Emergency Medical Services (EMS) data on medication and drug overdoses. OBJECTIVE: The purpose of this article is to describe the development and use of a variety of case definitions for poisoning and overdose implemented in NC's syndromic surveillance system and the impact of the system on local surveillance initiatives. DESIGN, SETTING, PARTICIPANTS: Thirteen new poisoning and overdose-related case definitions were added to NC's syndromic surveillance system and LHDs were trained on their use for surveillance purposes. Twenty-one LHDs were surveyed on the utility and impact of these new case definitions. RESULTS/CONCLUSIONS: Ninety-one per cent of survey respondents (n = 29) agreed or strongly agreed that their ability to access timely ED data was vital to inform community-level overdose prevention work. Providing LHDs with access to local, timely data to identify pockets of need and engage stakeholders facilitates the practice of informed injury prevention and contributes to the reduction of injury incidence in their communities.

Use of diagnosis codes for detection of clinically significant opioid poisoning in the emergency department: A retrospective analysis of a surveillance case definition.

BACKGROUND: Although fatal opioid poisonings tripled from 1999 to 2008, data describing nonfatal poisonings are rare. Public health authorities are in need of tools to track opioid poisonings in near real time. METHODS: We determined the utility of ICD-9-CM diagnosis codes for identifying clinically significant opioid poisonings in a state-wide emergency department (ED) surveillance system. We sampled visits from four hospitals from July 2009 to June 2012 with diagnosis codes of 965.00, 965.01, 965.02 and 965.09 (poisoning by opiates and related narcotics) and/or an external cause of injury code of E850.0-E850.2 (accidental poisoning by opiates and related narcotics), and developed a novel case definition to determine in which cases opioid poisoning prompted the ED visit. We calculated the percentage of visits coded for opioid poisoning that were clinically significant and compared it to the percentage of visits coded for poisoning by non-opioid agents in which there was actually poisoning by an opioid agent. We created a multivariate regression model to determine if other collected triage data can improve the positive predictive value of diagnosis codes alone for detecting clinically significant opioid poisoning. RESULTS: 70.1 % of visits (Standard Error 2.4 %) coded for opioid poisoning were primarily prompted by opioid poisoning. The remainder of visits represented opioid exposure in the setting of other primary diseases. Among non-opioid poisoning codes reviewed, up to 36 % were reclassified as an opioid poisoning. In multivariate analysis, only naloxone use improved the positive predictive value of ICD-9-CM codes for identifying clinically significant opioid poisoning, but was associated with a high false negative rate. CONCLUSIONS: This surveillance mechanism identifies many clinically significant opioid overdoses with a high positive predictive value. With further validation, it may help target control measures such as prescriber education and pharmacy monitoring.

Enhancing Tabletop X-Ray Phase Contrast Imaging with Nano-Fabrication.

X-ray phase-contrast imaging is a promising approach for improving soft-tissue contrast and lowering radiation dose in biomedical applications. While current tabletop imaging systems adapt to common x-ray tubes and large-area detectors by employing absorptive elements such as absorption gratings or monolithic crystals to filter the beam, we developed nanometric phase gratings which enable tabletop x-ray far-field interferometry with only phase-shifting elements, leading to a substantial enhancement in the performance of phase contrast imaging. In a general sense the method transfers the demands on the spatial coherence of the x-ray source and the detector resolution to the feature size of x-ray phase masks. We demonstrate its capabilities in hard x-ray imaging experiments at a fraction of clinical dose levels and present comparisons with the existing Talbot-Lau interferometer and with conventional digital radiography.

Motorcycle crash-related emergency department visits and hospitalizations for traumatic brain injury in North Carolina.

OBJECTIVE: To examine statewide emergency department (ED) visit data for motorcycle crash morbidity and healthcare utilization due to traumatic brain injuries (TBIs) and non-TBIs. SETTING: North Carolina ED data (2010-2012) and hospital discharge data (2009-2011). POPULATION: Statewide ED visits and hospitalizations due to injuries from traffic-related motorcycle crashes stratified by TBI status. DESIGN: Descriptive study. MAIN MEASURES: Descriptive statistics include age, sex, mode of transport, disposition, expected source of payment, hospital length of stay, and hospital charges. RESULTS: Over the study period, there were 18 780 ED visits and 3737 hospitalizations due to motorcycle crashes. Twelve percent of ED visits for motorcycle crashes and 26% of hospitalizations for motorcycle crashes had a diagnosis of TBI. Motorcycle crash-related hospitalizations with a TBI diagnosis had median hospital charges that were nearly $9000 greater than hospitalizations without a TBI diagnosis. CONCLUSIONS: Emergency department visits and hospitalizations due to motorcycle crashes with a TBI diagnosis consumed more healthcare resources than motorcycle crash-related ED visits and hospitalizations without a TBI diagnosis. Increased awareness of motorcyclists by other road users and increased use of motorcycle helmets are 2 strategies to mitigate the incidence and severity of motorcycle crash injuries, including TBIs.

Motionless electromagnetic phase stepping versus mechanical phase stepping in x-ray phase-contrast imaging with a compact source.

X-ray phase contrast imaging based on grating interferometers detects the refractive index distribution of an object without relying on radiation attenuation, thereby having the potential for reduced radiation absorption. These techniques belong to the broader category of optical wavefront measurement, which requires stepping the phase of the interference pattern to obtain a pixel-wise map of the phase distortion of the wavefront. While phase stepping traditionally involves mechanical scanning of a grating or mirror, we developed electromagnetic phase stepping (EPS) for imaging with compact sources to obviate the need for mechanical movement. In EPS a solenoid coil is placed outside the x-ray tube to shift its focal spot with a magnetic field, causing a relative movement between the projection of the sample and the interference pattern in the image. Here we present two embodiments of this method. We verified experimentally that electromagnetic and mechanical phase stepping give the same results and attain the same signal-to-noise ratios under the same radiation dose. We found that the relative changes of interference fringe visibility were within 3.0% when the x-ray focal spot was shifted by up to 1.0 mm in either direction. We conclude that when using x-ray tube sources, EPS is an effective means of phase stepping without the need for mechanical movement.

The epidemiology of traumatic brain injuries treated in emergency departments in North Carolina, 2010-2011.

BACKGROUND: Traumatic brain injuries (TBIs) are a leading cause of injury morbidity and mortality in the United States. An estimated 1.7 million TBIs occur each year, and TBIs may lead to severe lifelong disability and death; even mild-to-moderate TBIs may have long-term consequences. North Carolina's population-wide data on TBIs are limited, so it is important to analyze the available data regarding TBI-related emergency department (ED) visits. METHODS: Statewide data on TBI-related ED visits were obtained from the North Carolina Disease Event Tracking and Epidemiologic Collection Tool (NC DETECT), an electronic public health surveillance system. Counts and rates were produced by sex, age, county of residence, disposition, mode of transport, and mechanism of injury. RESULTS: In 2010-2011, there were 140,234 TBI-related ED visits in North Carolina, which yields a rate of 7.3 ED visits per 1,000 person-years. The rate was higher for men (7.9 visits per 1,000 person-years) than for women (6.8 visits per 1,000 person-years). Rates were highest in individuals aged 0-4 years (13.1 visits per 1,000 person-years), 15-19 years (10.6 visits per 1,000 person-years), 75-79 years (11.3 visits per 1,000 person-years), 80-84 years (17.9 visits per 1,000 person-years), and 85 years or older (30.6 visits per 1,000 person-years). TBI-related ED visits were principally the result of falls (39.0%), being struck by a person or object (17.6%), or motor vehicle traffic-related crashes (14.1%). LIMITATIONS: This study utilizes data collected primarily for administrative purposes, such as hospital billing. CONCLUSION: TBIs are a common cause of ED visits in North Carolina. These descriptive statistics demonstrate needs for statewide ED surveillance to monitor the incidence of TBIs and for the development of prevention strategies.

Efficient decoding of 2D structured illumination with linear phase stepping in X-ray phase contrast and dark-field imaging.

The ability to map the phase distribution and lateral coherence of an x-ray wavefront offers the potential for imaging the human body through phase contrast, without the need to deposit significant radiation energy. The classic means to achieve this goal is structured illumination, in which a periodic intensity modulation is introduced into the image, and changes in the phase distribution of the wavefront are detected as distortions of the modulation pattern. Two-dimensional periodic patterns are needed to fully characterize a transverse wavefront. Traditionally, the information in a 2D pattern is retrieved at high resolution by acquiring multiple images while shifting the pattern over a 2D matrix of positions. Here we describe a method to decode 2D periodic patterns with single-axis phase stepping, without either a loss of information or increasing the number of sampling steps. The method is created to reduce the instrumentation complexity of high-resolution 2D wavefront sensing in general. It is demonstrated with motionless electromagnetic phase stepping and a flexible processing algorithm in x-ray dark-field and phase contrast imaging.