1 Administrative Delays And Secondary Disability Following Occupational Low Back Injury California Commission on Health and Safety and Workers’ Compensation Research Colloquium Patricia L. Sinnott, PT, MPH May 1, 2003

2 Introduction Low back pain in the workplace:  5 – 20% of all claims.  30 – 40% of all costs.  20-30% of low back claims produce % of low back costs.  2/3 of low back costs are for indemnity payments.  Majority of these costs are produced by injured workers who are off 3 months or more.

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4 Research to Date Extensive but not conclusive. Requires multifactorial approach. The Holy Grail: to find reasons why some workers return to work quickly and some do not.

5 Healthcare Research That medical diagnosis and treatment not wholly predictive of outcomes. That patient expectations, perceived needs and reaction to care play significant part in prediction of good outcomes.

6 Workers’ Compensation Research Physical Effects Psychological Effects Workplace Accommodation Early intervention But no one influence explains all the variation.

7 The Individual Economic and Environmental Influences Healthcare System Family and Social Support Employer And Payer System Individual

8 Background Claim delay is a necessary procedure used to determine compensability and liability and to identify fraud. However: Claim delay may introduce an adversarial interaction between employer and employee. Claim delay may hinder access to medical treatment.

9 Claim delay may interfere with early intervention, positive reinforcement and workplace accommodation supported in the literature. Claim delay may increase physiological and psychological stress associated with the original injury. Claim delay may require repetition and reinforcement of the complaints by the injured.

10 Reinforcement of the complaints may slow progress, institutionalize pain behavior, and may promote intentional or unintentional exaggeration of symptoms.

11 Hypotheses Individuals injured at work and take any temporary disability days, who experience delays in claim acceptance are more likely to take more than 91 days off than those who do not experience delays. Individuals who experience longer delays will have an increased probability of taking 91 days or more of TD.

12 The Data California Workers' Compensation Institute ICIS dataset Contributing carriers represent 70%+ of the premium in the market All claims from 1993 – 2000 Administrative data

13 Case Definition New claim for non specific low back pain/injury Non traumatic injury No fractures, falls, motor vehicle crashes, systemic illnesses, neoplasm or pregnancy At least one day of temporary disability paid

14 Key Control Variables Individual characteristics: age, gender, tenure, wage, full-time status, home zip. Clinical variables: severity classified by diagnostic complexity. Work and work environment: employer size, employer industry. Medical care characteristics: days to first treatment; Provider experience. Time.

15 Key Study Variables Delay: days of delay to claim acceptance calculated as days between the first date of TD and the date of the first check paying TD. Outcome: 2 possible: takes 91 days or more of TD or not.

16 Analysis Logistic model to estimate the probability of taking 91 days or more of TD. Then calculate: Conditional probabilities estimated based on length of delay.

17 Descriptive Results observations: 74.01% male Mean age: 36.8 years Average weekly wage: $ Mean tenure: 4.44 years 87.5% worked full-time 47.27% worked in the agriculture and mining sector % of claims from employers with <= 50 employees

% of the TD cases were classified as least severe 60.87% were delayed 14 days or less 5.85% were delayed 91 days or more Descriptive Results

19 Total Days off 50.62% off 30 days or more 38.42% off 60 days or more 32.% off 91 days or more off 120 days or more* Mean TD days off = 109

20 Adjusted Odds Ratios Construction OR=1.29 Riverside OR=1.42 Santa Barbara OR=1.50 Moderately severe OR=3.74 Most severe OR =6.85

21 Delays Adjusted odds ratio 15 –28 days days – 56 days days days1.710 >= 91 days2.006

22 Conditional Probabilities 25% 41% 56% 34% 72% 70% 78% 83%

23 Summary of Findings Women are slightly more likely than men to take 91 days or more of TD. The least severe cases have a 25% probability of taking 91 days or more if the case is delayed less than 14 days The most severe cases have > = an 80% probability of taking 91 days or more of TD if delayed days. The probability of taking 91 days or more of TD increases 30% from day 1 to 56 days

24 There is a range of 25 – 70% probability of taking more than 91 days of TD at onset dependent upon severity But: Severity is not likely known at onset.

25 Policy Implications  Contributes to understanding of influence of delay, but not how delay influences.  Identifies a component of the administrative system which the employer and payer can influence.  Potential for cost savings must be balanced with potential for expansion of claim base.

26 Acknowledgements California Workers’ Compensation Institute Foundation for Physical Therapy