Hospital variation in admissions for low back pain following an emergency department presentation: a retrospective study

Abstract

Background One in 6 patients with low back pain (LBP) presenting to emergency departments (EDs) are subsequently admitted to hospital each year, making LBP the ninth most common reason for hospital admission in Australia. No studies have investigated and quantified the extent of clinical variation in hospital admission following an ED presentation for LBP. Methods We used routinely collected ED data from public hospitals within the state of New South Wales, Australia, to identify presentations of patients aged between 18 and 111 with a discharge diagnosis of LBP. We fitted a series of random effects multilevel logistic regression models adjusted by case-mix and hospital variables. The main outcome was the hospital-adjusted admission rate (HAAR). Data were presented as funnel plots with 95% and 99.8% confidence limits. Hospitals with a HAAR outside the 95% confidence limit were considered to have a HAAR significantly different to the state average. Results We identified 176,729 LBP presentations across 177 public hospital EDs and 44,549 hospital admissions (25.2%). The mean (SD) age was 51.8 (19.5) and 52% were female. Hospital factors explained 10% of the variation (ICC = 0.10), and the median odds ratio (MOR) was 2.03. We identified marked variation across hospitals, with HAAR ranging from 6.9 to 65.9%. After adjusting for hospital variables, there was still marked variation between hospitals with similar characteristics. Conclusion We found substantial variation in hospital admissions following a presentation to the ED due to LBP even after controlling by case-mix and hospital characteristics. Given the substantial costs associated with these admissions, our findings indicate the need to investigate sources of variation and to determine instances where the observed variation is warranted or unwarranted.

Global prevalence of hospital admissions for low back pain: a systematic review with meta-analysis

“…We analysed the proportion of low back pain admissions from ED from 3 government reports25 28 43 and 20 peer-reviewed studies14 16–19 40 42–56 (table 1). Seven studies were from healthcare systems with predominantly private funding, 16 with predominantly public funding.…”

“…The majority of included studies were from urban, university-affiliated tertiary care centres. Only two included studies, both from New South Wales, Australia,14 18 presented a breakdown of admission data from both urban and rural settings.…”

“…In the USA, 65% of all low back pain admissions are unscheduled admissions through the ED 11. The estimated prevalence of low back pain admissions in low-income and middle-income countries has not been well studied, but the available studies suggest that it is a global healthcare issue 12–14. A cost of illness study in Brazil identified 118 705 low back pain admissions over 5 years (2012–2016), with those aged 39–58 years identified as accounting for 48% (64 002/133 971) of inpatient hospital days 15…”

“…We know that admission rates for low back pain as a proportion of ED presentations vary greatly even within similar healthcare settings. One study of 177 New South Wales (Australia) EDs reported that the admission rate for low back pain ranged from 7–66% 14. Two other recent Australian studies reported that 18%16 (public hospital) and 53%17 (private hospital) of low back pain presentations to the ED were subsequently admitted as inpatients.…”

Identification and classification of principal features for analyzing unwarranted clinical variation

“…The classification of features is shown in Figure 1 Race and ethnicity 18 (39) 18 [9][10][11][12][13][14][15]17,21,23,28,29,[35][36][37][38]45,49 Social Socioeconomic status 30 (65) 30 [9][10][11][12][13][14][15][16] Social risk factors 12 (26) 12 [10][11][12][13][14][15][16][18][19][20][21]45 Clinical characteristics Patient profile N/A Body mass index 7 (15) 7 20,23,34,[39][40][41]49 History Comorbidity 29 (63) 29 [9][10][11]13,[15]…”