Duration of Patients' Visits to the Hospital Emergency Department

Zeynal Karaca; Herbert S Wong; Ryan L Mutter

Disclosures

BMC Emerg Med. 2012;12(15) 

In This Article

Results

Descriptive Results

Admission Hour and Day of the Week. Duration of visits varied substantially by admission hour and day of the week. At the 95th percentile, the mean duration of T&R ED visits was between 194.2 and 197.2 minutes. We found that the distribution of duration of ED visits was right-skewed. Therefore, we explored the relationship between total volume of visits with both mean and median duration at EDs by admission hour.f As shown in Figure 1, the mean duration of ED visits increased from 8 a.m. until noon, then decreased until midnight at which time we observed an approximately 70-minute spike in mean duration. One plausible explanation for this might be that healthcare personnel change shifts at this time and/or a reduction in other resources between 11 p.m. and midnight. Another plausible explanation might be that healthcare personnel might experience a decrease in their labor productivity towards the end of their shifts. After midnight, we noticed decreases in duration of ED visits until early morning, and increases thereafter.

Figure 1.

Duration of treat-and-release visits at emergency departments by hour. Data includes all treat-and-release emergency visits during 2008 in Arizona, Massachusetts and Utah. Duration is measured in minutes as the difference between admission time and discharge time for each visit.

Next, we explored the relationship between total number of visits and admission hour. As presented in Figure 1, the number of ED visits rose from 5 a.m. until reaching its highest level around noon. It stayed around peak volume until 6 p.m., and then decreased sharply—reaching its lowest volume just before 5 a.m. There may be many factors related to staffing, total number of patients in the ED, especially during the night shift, that contribute to the change over time. We further explored the relationship between admission hour and duration of ED visits by hospital characteristics. As presented in Figures 2 and 3, at both teaching and non-teaching hospitals, the mean duration of ED visits increased from 8 a.m. until noon, then decreased until midnight, at which time we observed spikes in mean duration of ED visits of 96 minutes at teaching hospitals, and 89 minutes at non-profit hospitals. In contrast, we did not observe a substantial increase in mean duration at for-profit or public hospitals. As shown in Figure 4, the mean duration of ED visits increased from 6 p.m. until midnight, at which time we observed a 41-minute spike in mean duration. The mean duration of ED visits at public hospitals was stable when compared to other hospital types. Figure 5 shows that there was a slight increase in mean duration of ED visits at public hospitals during the early morning and late night hours. As shown in Figures 2 and 3, the patterns of the variation of median and mean duration of ED visits throughout the day at teaching hospitals and non-profit hospitals were similar. However, at for-profit hospitals and public hospitals, the median duration was very stable at around 120 minutes throughout the day (Figures 4 and 5).

Figure 2.

Duration of treat-and-release visits at emergency departments of teaching hospitals by hour. Data includes all treat-and-release emergency visits during 2008 in Arizona, Massachusetts and Utah. Duration is measured in minutes as the difference between admission time and discharge time for each visit.

Figure 3.

Duration of treat-and-release visits at emergency departments of non-profit hospitals by hour. Data includes all treat-and-release emergency visits during 2008 in Arizona, Massachusetts and Utah. Duration is measured in minutes as the difference between admission time and discharge time for each visit.

Figure 4.

Duration of treat-and-release visits at emergency departments of for-profit hospitals by hour. Data includes all treat-and-release emergency visits during 2008 in Arizona, Massachusetts and Utah. Duration is measured in minutes as the difference between admission time and discharge time for each visit.

Figure 5.

Duration of treat-and-release visits at emergency departments of public hospitals by hour. Data includes all treat-and-release emergency visits during 2008 in Arizona, Massachusetts and Utah. Duration is measured in minutes as the difference between admission time and discharge time for each visit.

There is growing concern among healthcare providers and policymakers about ED LOS on Mondays. We repeated the secondary data analyses to empirically show the differences, if any, between visits on Mondays and other weekdays or the weekend. As shown in Figures 6, 7, and 8, the mean duration of ED visits on the weekend were slightly shorter than that for visits on Mondays or other weekdays. For example, the mean duration of ED visits for patients arriving at 8 a.m. on Mondays, other weekdays, and weekends were about 184, 189, and 172 minutes, respectively. We found sizable difference in mean duration of ED visits between Mondays and other weekdays (over 90 minutes) only during the transition time from the evening of the day before to early morning hours (i.e., between midnight and 2 a.m.). While we observed a systematic increase in mean duration of ED visits during hours near midnight regardless of the admission day, we calculated that the increase was substantially larger on Mondays when compared to other weekdays or the weekend. This finding supports the hypothesis that our nation's EDs may lack adequate resources to see patients on a typical Monday.[14]

Figure 6.

Duration of treat-and-release visits at emergency departments on Mondays by hour. Data includes all treat-and-release emergency visits during 2008 in Arizona, Massachusetts and Utah. Duration is measured in minutes as the difference between admission time and discharge time for each visit.

Figure 7.

Duration of treat-and-release visits at emergency departments on Non-Monday weekdays by hour. Data includes all treat-and-release emergency visits during 2008 in Arizona, Massachusetts and Utah. Duration is measured in minutes as the difference between admission time and discharge time for each visit.

Figure 8.

Duration of treat-and-release visits at emergency departments on weekends by hour. Data includes all treat-and-release emergency visits during 2008 in Arizona, Massachusetts and Utah. Duration is measured in minutes as the difference between admission time and discharge time for each visit.

The mean, median and inter-quartiles (i.e., 25th and 75th quantiles) of duration across admission hours for the various characterizations reported in Figures 1, 2, 3, 4, 5, 6, 7, 8 showed very little variations. While the upper range was consistent at about 500 minutes for all visits (Figure 1), there were some variations for specific characterizations (i.e., Figure 2, teaching hospitals).

Patient Characteristics. We analyzed patient demographics to explore potential explanations for the long duration of ED visits we observed (194.2 – 197.2 minutes). Table 1 displays the total number of T&R ED visits, mean duration of visits, and corresponding 95% confidence intervals for various patient characteristics. As shown in Table 1, the mean duration of visit increased with the age of the patient. We observed that the mean duration of ED visits for patients over 74 years of age was noticeably higher when compared to visits for patients younger than 15 years of age (237.5 versus 142.2 minutes). We also observed about 15 minutes longer mean duration of ED visits for female patients when compared to male patients.

We also analyzed the mean duration of ED visits across race groups. As show in Table 1, the duration of ED visits for black/African American and Hispanic patients, respectively, was 11.2% and 6.2% longer than the duration of visits for non-Hispanic white patients. Our results support the findings of Herring et al. (2009) who found longer ED LOS for black/African American non-Hispanic patients (10.6% longer) and Hispanic patients (13.9% longer) when compared to non-Hispanic white patients.

Next, we analyzed the mean duration of ED visits by insurance coverage type. We found that Medicare patients' visits had the longest mean duration (237.7 minutes), which could be due to higher severity of illness and presence of multiple diseases among these patients. Similarly, as shown in Table 1, the mean duration of ED visits for patients with Medicaid, private insurance, other insurance (e.g., TRICARE, worker's compensation, health safety net, and other government payments or non-managed care plans) and no insurance coverage were 182.8, 192.8, 169.4, and 191.8 minutes, respectively. These results suggest that the difference in mean duration of ED visits between patients with any insurance coverage and uninsured patients is negligible. This result can also be interpreted as a positive sign that uninsured patients face limited barriers to healthcare access at emergency department settings.

Finally, we explored the potential relationship between the mean duration of visits and various disease groups as an assessment of severity of illness. As presented in Table 1, patients with diseases of blood and blood forming organs, neoplasm, and mental disorders experienced the longest mean duration of ED visits (327.3, 286.8, and 284.0 minutes, respectively). We observed the shortest ED stays among patients diagnosed with diseases of skin and subcutaneous tissue, injury and poisoning, and perinatal conditions (160.0, 159.6, and 140.5 minutes, respectively). These results highlight the impact of clinical severity of diseases on the mean duration of ED visits.

Hospital Characteristics and Area Characteristics. Next, we analyzed hospital and area characteristics to explore other potential associations with longer ED visits. As shown in Table 2, hospitals with large bed sizeg were associated with the longest duration of visits (222.2 minutes) when compared to hospitals with small bed size (172.4 minutes) or with medium bed size (166.5 minutes). Similarly, the mean duration of ED visits at urban hospitals was 26.8 minutes longer than those at their rural counterparts. Recognizing the differences in income levels across geographic regions, we compared the mean duration based on income distribution. We did not find significant differences in mean duration of ED visits between relatively richer or poorer counties. We also observed that the mean duration of visits at hospitals that are members of a hospital system was 6.7% shorter when compared to non-member hospitals. Similarly, the mean duration of visits at Level 1 trauma centers was 278.2 minutes and substantially longer than those at Level 2 or Level 3 trauma centers or non-trauma centers. One plausible explanation for this result is that Level 1 trauma centers provide the highest level of surgical care to seriously injured patients who may use more resources and whose treatments last longer. In contrast to visits at Level 1 trauma centers, the mean duration of visits at Level 2 and Level 3 trauma centers were shorter by more than 45 minutes compared to those at the non-trauma centers. When we looked more closely at the discharge positions of patients at non-trauma centers versus those at Level 2 and 3 trauma centers, we found that non-trauma centers have a relatively higher shares of patients transferred to short-term hospitals or other facilities. It might be plausible to assume that relatively higher shares of patients discharged to other facilities might be driving the difference since this discharge position is generally associated with longer duration of ED visits.

Table 2 also shows that the mean duration of visits at teaching hospitals was substantially higher than at non-teaching hospitals (243.8 versus 175.6 minutes). The mean duration of visits at public, non-profit, and for-profit hospitals was 180.0, 202.5, and 178.4 minutes, respectively, showing significant differences between for-profit and non-profit hospitals (where duration was 13.5% longer). One plausible reason for the difference could be the different financial incentives for for-profit and non-profit hospitals. We further analyzed the mean duration of visits throughout the day to uncover any significant differences. Figure 3 shows that the mean duration at non-profit hospitals was substantially higher for the majority of the day when compared to for-profit hospitals, except between 8 p.m. and 1 a.m. During the late evening period, non-profit hospitals showed lower mean duration when compared to for-profit hospitals. For example, the mean duration of ED visits from 10 p.m. to 12 a.m. was about 70 minutes shorter at non-profit hospitals when compared to their for-profit hospitals.

Finally, we analyzed patients' discharge disposition from EDs by hospital and area characteristics to further explore other potential associations with longer ED visits. As shown in Table 3, the mean duration of ED visits for patients discharged to home health care was substantially higher when compared to patients discharged elsewhere. The mean duration of visits for patients transferred to home health care and other long-term care facilities were about 871 minutes and 507 minutes respectively. The mean duration of ED visits for patients discharged home and patients discharged against medical advice were about 187 and 209 minutes, respectively. As presented in Table 3, the mean duration for patients visiting EDs at urban hospitals were substantially higher when compared to rural hospitals regardless of patients' discharge disposition. Similarly, mean duration of visits at teaching hospitals relative to non-teaching hospitals and at non-profit hospitals relative to for-profit were considerably longer for patients transferred to short-term hospitals or other facilities. The mean duration of ED visits was also higher in Level 1 trauma centers when compared to non-trauma, Level 2, and Level 3 trauma centers across patients' discharge status, except when the patient died in the hospital. Patients visiting EDs of hospitals with large bed size experienced longer duration regardless of their discharge status when compared to hospitals with small or medium bed sizes. Finally, the mean duration of ED visits at hospitals that were members of a hospital system was slightly higher when compared to hospitals that were not members of hospital systems.

Regression Results

Table 4 presents regression results that convey the impact of admission day of the week, patient demographics, and hospital characteristics on duration of patients' visits to EDs. All results are highly statistically significant for all variables across all models except hospital characteristics estimated under the multilevel model. Average duration of visits on Mondays is at least 4 percent and 9 percent more than the average duration of visits on non-Monday workdays and on weekends, respectively. The results also show that average duration of ED visits for older patients or female patients is generally longer when compared to younger patients or male patients. Non-white patients generally experience longer duration of ED visits when compared to white patients. When compared to patients with other primary payers, Medicare patients are generally associated with longer duration of ED visits, and uninsured patients or patients who pay out-of-pocket are generally associated with shorter duration of ED visits.

The regression results presented in Table 4 show that patients visiting teaching hospitals and Level 1 trauma centers generally experience longer duration of ED visits. Average duration of patient's visits to Level 2 and Level 3 trauma centers are generally shorter when compared to the duration of ED visits at non-trauma hospital centers. Patients visiting urban hospitals experience longer duration of ED visits when compared to patients visiting rural hospitals. Similarly, the average duration of ED visits to hospitals with large or medium bed size is shorter than the average duration of ED visits to hospitals with small bed size. Table 4 also provides crucial information about the source of variation in duration of ED visits. The intra-class correlation coefficient obtained through multilevel regression analysis indicates that about 56 percent of variations in duration of patients' visits to EDs are due to variation within patients clustered by hospitals. Alternatively, hospitals are accountable for less than 45 percent of total variations in duration of ED visits.

Limitations

As mentioned earlier, measures of timeliness of care in the ED that have been advanced in the literature are not available in HCUP data. Therefore, we computed the duration for each visit by taking the difference between admission and discharge times, which is the total time patients were waiting in the ED plus their treatment and discharge times.

The HCUP SEDD data is based on ED encounters as the unit of analysis, so a given patient may have many visits. As a consequence, the summary information reported under patient characteristics might overestimate or underestimate demographics for individual patients. Finally, this study does not address the impact of financial incentives and other confounding factors across hospitals types on duration of ED visits.

Our analysis is confined to the T&R ED data presented in the HCUP SEDD from only three states: Arizona, Massachusetts, and Utah. Relatively small sample sizes may contribute to some of our findings, such as observing a skew in duration around Monday midnight. ED encounters that result in subsequent admission to the same hospital are not included in the analysis. Patients that are admitted, and perhaps boarded, might have different experiences than those presented in our results. There can also be considerable variations at the facility-level in the rate at which patients are admitted from the ED. Therefore, the EDs contained in this analysis may have considerably different mixes in the number of patients that they treat and release and those that they admit.

fWe focus mainly on the mean value of duration in our analysis. However, we have provided both mean and median values for each measure separately throughout all tables and figures to set the stage for further research and to provide additional detail to key policymakers and curious researchers.
gFurther details about hospital bed sizes are available at http://www.hcup-us.ahrq.gov/db/vars/hosp_bedsize/nisnote.jsp.

Comments

3090D553-9492-4563-8681-AD288FA52ACE

processing....