Determining the Prevalence and Costs of Unnecessary Referrals in Adolescent Idiopathic Scoliosis

Abstract

Background:

Adolescent idiopathic scoliosis (AIS) has been associated with unnecessary referrals, but the provider and patient costs associated with these referrals remain unknown. The purpose of this study was to determine the prevalence and associated costs of unnecessary referrals for AIS in a university hospital-based orthopaedic clinic. These data are required to estimate the cost-efficacy of scoliosis screening programs.

Methods:

We accessed the electronic medical records of all patients referred during 2013-2014 with suspected AIS. Spine radiographs were reviewed to determine whether the referral was “unnecessary,” defined as a Cobb angle <20 degrees. Patient and provider costs were estimated. Patient costs included transportation expenses and parental lost wages. Provider costs included orthopaedic evaluation, diagnostic imaging, and overhead. Transportation costs were based on actual driving distances and the Internal Revenue Service standard mileage rate. Parental lost wages and the cost of evaluation by an orthopaedic surgeon were calculated with time-driven activity-based costing. Diagnostic imaging costs were calculated with a traditional activity-based costing methodology.

Results:

Three hundred thirty-seven patients were included. The prevalence of unnecessary referrals was 39% (n=131). 17% of patients had a Cobb angle <10 degrees and 22% had a Cobb angle between 10-20 degrees. Males were more likely to be referred unnecessarily than females, 49% to 35% (p=0.02) as were non-Caucasians (54% vs. 37%, p=0.04). No difference was noted related to source of insurance (private or public, p=0.18). The average total cost of an unnecessary referral was $782.13 USD, including $231.07 in patient costs and $551.06 in provider costs.

Conclusions:

Nearly 40% of all referrals for AIS were deemed unnecessary. The average cost of an unnecessary referral is approximately $780, imposing significant costs on both patients and the healthcare system.

Level of Evidence: III

Introduction

The United States spends more money on health care than any other nation in the world.¹ Increasing health care expenditures have become a major policy focus of politicians and health care administrators. One of the factors contributing to rising health care costs is the high number of unnecessary referrals to specialists. Barnett et al. demonstrated that referral rates in the United States nearly doubled between 1999 and 2009.² Changes in referral rates have led to increased health care costs, as patients referred to a specialist typically utilize more healthcare resources than those not referred.^3,4 Minimizing costs associated with unnecessary referrals to specialists is critically important to improving value-based healthcare delivery.⁵

Data from a Canadian community without a school-screening program suggests adolescent idiopathic scoliosis (AIS) is associated with a high rate of unnecessary referrals to orthopaedic surgeons.⁶ At the current time, there is limited data on the prevalence and cost of unnecessary referrals for AIS in the United States. This data is critical to determining the cost-efficacy of community-based programs and screening provided during primary care encounters.

This investigation seeks to define the prevalence and cost of unnecessary referrals for AIS in a United States community without a state-mandated screening program. All direct and indirect costs related to referral were considered including transportation expenses, parental lost wages, orthopaedic evaluation, diagnostic imaging, and clinic overhead.

Methods

Sample

This investigation is a retrospective review of all patients who presented to a single orthopaedic surgeon at a tertiary care hospital-based clinic during 2013 and 2014 for evaluation of AIS or possible AIS. Prospective cost accounting techniques were used to accurately capture all direct and indirect expenses associated with referral.

The records of all new patients, age 10-19 years, evaluated by a single pediatric orthopaedic surgeon during 2013 and 2014 with ICD-9 codes of 737.30, 737.8, 737.9, 738.5, 754.2, and V65.5 were reviewed. Any patient with a neuromuscular, congenital, or other non-idiopathic scoliosis was excluded, as was any patient with previous spinal surgery. Finally, all orders for scoliosis spine radiographs were reviewed to ensure no patient was missed due to errant coding. Only those records that noted ‘scoliosis evaluation’ as the reason for referral were retained in the study sample. Demographic data was abstracted. For all patients included in the investigation, spine radiographs were reviewed and Cobb angles were recorded.

In addition, a prospective cross-sectional survey of parents and caretakers was used to collect data needed for estimation of transportation costs and parental lost wages as these data were not available in the medical record. The survey was offered to all parents attending the clinic visit with a child being evaluated for scoliosis; no parent declined. For each patient, we recorded how many parents were present for the appointment and the gender of any parent in attendance. We also asked each parent to estimate how long it took to navigate to the clinic from the parking lot (wayfinding time).

Prevalence of Unnecessary Referrals

The patient’s maximal Cobb angle determined whether a referral was necessary. Referral of patients with a Cobb angle less than 20 degrees was deemed unnecessary, and referral of patients with Cobb angles of at least 20 degrees was deemed necessary. The 20-degree threshold was based upon expert opinion and previous literature,⁷ and also because treatment is not typically offered to patients with curves below 20 degrees. Unfortunately, we were unable to find recommendations from any major professional organization guiding referring physicians as to what constitutes an appropriate referral in terms of curve severity.

Patients were also stratified by gender, insurance status (public or private), and race (Caucasian or other). The impact of gender, insurance status, and race on the rate of unnecessary referrals and the presenting Cobb angle was assessed.

Transportation Costs

The costs associated with patient travel were estimated by using an online distance calculator along with standard mileage rates from the Internal Revenue Service (IRS).⁸ The distance from the patient’s home address to the hospital was calculated. If a patient’s home address was not found in the distance-calculating program, the center of the patient’s home city was used. Those residing more than 350 miles from the hospital were excluded due to both their outlier effects and the increased probability of the family using air travel. The calculated distance was multiplied by the standard mileage rates available from the IRS. The “business miles” rate was used. This rate includes all fixed and variable costs of operating a motor vehicle. For clinic visits occurring in 2013, the rate was 56.5 cents. For clinic visits in 2014, the rate was 56.0 cents.

Parental Lost Wages

The educational attainment, county of residence, and sex of each of the parents of each patient in the retrospective sample were extracted from the medical record. These variables were then cross referenced with earnings data from the U.S. Census Bureau to estimate each parent’s annual salary.⁹ The salary was divided by 2087 hours to determine the parent’s hourly wage.¹⁰

To determine parent lost time, an estimate of driving time (determined by the distance calculating program) and wayfinding time was added to the time in office (patient’s check-in time to check-out time). This lost time estimate was multiplied by the hourly wage to determine lost wages. Finally, these lost wages were multiplied by the probability of a parent of a specific gender was present at the clinic visit, which was estimated by the cross-sectional survey as described above. For example, Maternal Lost Wages = [(Driving time)+(Wayfinding time)+(Length of Clinic Appointment)]*(Mother’s hourly wage estimate)*(Probability mother was present at the appointment).

Provider Costs

Orthopaedic physician costs were calculated with a time-driven activity-based costing (TDABC) methodology,¹¹ which accounts for all costs of employing a provider including salary, benefits, administrative support, and department overhead. The resulting per minute cost rate was multiplied by the time a provider dedicated to each patient’s visit, measured prospectively with a stopwatch. Clinic overhead costs were calculated with a traditional activity-based costing methodology. These costs included hospital overhead, non-physician (e.g. medical assistant) labor, and utilities. This costing methodology has been shown to be more accurate than traditional relative-value unit based methods in other areas of orthopaedic surgery.¹²

Radiography costs were estimated by a traditional activity-based costing methodology. In our clinic, outside radiographs are first screened by a staff member to assess if they were adequate to determine the diagnosis of AIS. If not, new spine radiographs were taken. Therefore, because adequate spine radiographs are necessary for the diagnosis of AIS, all spine radiographs taken at the clinic were deemed necessary. Hand radiographs were also taken of all new patients to determine the Sanders skeletal maturity stage and assist in AIS treatment decisions. However, in patients who were not consequently assigned a diagnosis of AIS, hand radiographs for bone age were considered unnecessary. Costs of unnecessary hand radiographs were included when calculating the cost A burden of unnecessary referrals.

Statistical Analysis

The sample demographics and presenting Cobb angle are summarized using the average and percentage for the sample overall and stratified by type of referral. Differences in the average Cobb angle between gender, insurance and race by referral type were evaluated via independent t-tests; differences in sample proportions by referral type were evaluated using the Chi-square test. The threshold for statistical significance was set at alpha=0.05.

Results

337 patients met the inclusion criteria for the retrospective sample and their electronic medical records were reviewed. 24 patients and 32 parents who accompanied AIS patients to a clinic visit were included in the cross-sectional portion of the study.

Sample Characteristics and Prevalence of Unnecessary Referrals

The proportion of unnecessary and appropriate referrals by sex, race and insurance (private or public) is summarized in Table 1. Of the 337 patients, 74% (n=284) were female, 86% (n=290) were Caucasian, and 84% (n=284) had private insurance. 39% (n=131) were referred unnecessarily, defined by a maximum Cobb angle of less than 20 degrees. 17% were referred with a Cobb angle of less than 10 degrees.

Table 1.

Unnecessary and Appropriate Referrals by Sex, Race and Insurance

Total	n (%)	Mean Cobb Angle at Referral	Unnecessary Referral (0-19°) n (%)	Appropriate Referral (20°+) n (%)	p value
All Referrals	337 (100)	26.23	131 (39)	206 (61)
Sex
Female	248 (74)	28.00	87 (35)	161 (65)	0.02
Male	89 (26)	21.40	44 (49)	45 (51)
Race
Caucasian	290 (86)	26.63	106 (37)	184 (63)	0.04
Other	41 (14)	23.61	22 (54)	19 (46)
Insurance
Private	284 (84)	26.49	107 (38)	177 (62)	0.18
Public	48 (16)	23.83	23 (48)	25 (52)

Females presented with an average Cobb angle of 28 degrees compared to 21 degrees for males (p = 0.001). Consequently, more males were unnecessarily referred (49%) than females (35%) (p=0.02). Caucasians were less likely to be unnecessarily referred than other racial groups (37% vs. 54%, p=0.04). Having private or public insurance was not significantly associated with the appropriateness of the referral (p=0.18).

Transportation Costs

The average family traveled 172.4 miles ± 124.8 (range 2.4 - 594 miles) to visit the clinic and return home, resulting in an average cost of $98.34 ± $70.20 (range $1.34 - $335.61).

Parental Lost Wages

Of the 24 patient visits included in the cross-sectional study, the mother was present in 96%, and the father was present in 38%. Combining data from these visits to data from the retrospective chart review, we estimated total parent lost time averaged 322.7 minutes and included an average of 177.9 ± 113.9 minutes of driving, 16.4 ± 12.0 minutes of wayfinding, and an average of 128.4 ± 38.0 minutes in clinic. This resulted in an average total wage loss per family of $132.73 ± $60.60 (range $34.26 - $512.31).

Hospital Costs

Patients were first seen by either a mid-level provider (44%) or a resident physician (56%), followed then by the staff physician. The mid-level provider spent an average of 32.0 minutes with each patient, the resident averaged 39.6 minutes, and the staff physician averaged 11.2 minutes. The labor cost of the orthopaedic healthcare providers for a single visit averaged $118.96.

Clinic overhead costs were $193.11 per patient, and the cost of unnecessary radiography, (hand films to establish skeletal maturity during an inappropriate referral), was $239.00 per patient.

Cost Summary

In total, the average cost of an unnecessary AIS referral was $782.13. Average patient costs (travel, lost wages) were $231.07 and average provider costs (provider time, clinic overhead, radiography) were $551.06.

Discussion

Nearly 40% of referrals for AIS to our clinic were medically unnecessary, as defined by a Cobb angle of less than 20 degrees. The average cost of an unnecessary referral was $782.13, with more than half that amount attributable to provider-side costs. Male and non-Caucasian patients were more likely to be referred unnecessarily. The insurance provider was not associated with the appropriateness of the referral.

Currently, there is not a consensus in the literature as to what constitutes an appropriate referral. The American Academy of Pediatrics released guidelines in 2014 for referral to a pediatric surgical specialist.¹³ The guidelines include “infants, children, and adolescents with significant spinal deformity (scoliosis or kyphosis)” as grounds for a referral to a pediatric orthopaedic surgeon. However, the authors fail to define what “significant” means in this context. In addition, these guidelines do not distinguish between the type of scoliosis (e.g., infantile, juvenile, adolescent, neuromuscular, congenital) or the stage of the disease. While there is a question as to which AIS patients with curves of 21-30 degrees should be referred, most published literature agrees that referral of patients with less than 20 degree curves is unnecessary.^7,14,15 Since the present investigation only defines referrals as unnecessary for curves less than 20 degrees, the incidence may be somewhat underestimated. Further clarification from professional organizations as to which patients should be referred for specialist treatment could be instrumental in decreasing the number of unnecessary referrals.

The prevalence (39%) of patients presenting with curves less than 20 degrees noted in this sample is lower than other prior investigations. Hines et al. reported that 67% of patients at Texas Scottish Rite Hospital for Children presented with curves of less than 20 degrees, albeit based on a small sample (n=27).¹⁶ In a Montreal study, Beauséjour et al. reported 42% of referred patients had curves of less than 10 degrees, and 67% had curves of less than 20 degrees.⁶ It seems plausible that rates of unnecessary referrals may vary across investigations due to geographic variations and the presence or absence of community screening programs. The majority of patients included in the current study live in a predominately rural section of the Midwest. The long travel distances noted in this sample may explain the lower rate of unnecessary referrals.

In 2015, the Scoliosis Research Society, American Academy of Orthopaedic Surgeons, American Academy of Pediatrics, and the Pediatric Orthopaedic Society of North America called on the United States Preventive Services Task Force (USPSTF) to review its recommendation against screening for AIS in light of new research evidence supporting bracing, and to a lesser degree, screening.^17,18,19 Upon review, the USPSTF found insufficient evidence to recommend for or against the practice of screening, citing lack of evidence that screening leads to improved patient-reported outcomes in adulthood.²⁰ We anticipate that state health departments may cancel mandatory screening programs as a result of this review, but it is unlikely that primary care providers will eliminate spine and posture examinations during well child checks or sports physicals, and will instead continue to refer patients to orthopaedic surgeons when asymmetries are noted. Since Iowa does not have a statewide mandate to provide community screening, we do not foresee a significant decrease in referrals as a result of the updated recommendation, although its effect in other states remains to be seen.

It is important to consider the financial impact screening and consequent referrals can have on families. A single unnecessary referral can create a financial burden to a family. To put the patient cost of $231.07 into perspective, one should consider that in 2011 the average family had only $3050 in interest-earning assets at financial institutions and regular checking accounts.²¹ While harm from unnecessary radiation or treatment are often discussed, our study suggests financial harms should also be recognized and taken into consideration. This emphasizes the need for a screening protocol with not only a high sensitivity, but a high specificity as well.

Our study is the first to examine the costs associated with unnecessary referrals for AIS using TDABC and primary data, in contrast to prior investigations relying on charges or reimbursements.²² The accuracy of our cost estimates could have been improved if radiography and overhead costs were calculated with TDABC instead of activity-based costing. Prior work by Akhavan et al. suggests that the ABC methodology may overestimate actual costs.¹² Nonetheless, the cost data reported herein are essential to appropriately assessing the cost-efficacy of scoliosis screening programs. Establishing the value of community- and provider-based scoliosis screening programs is critical to value-based healthcare delivery in pediatric orthopaedics.