Table 1 Risk factors investigated in the present study

Age group

Age groups in 10 year age bands as per the Australian Bureau of Statistics (www.abs.gov.au);

Gender

Male/Female

Worker condition

Worker condition at the initiation of claim

Postcode

Local government area postcode transformed to the residential location: metro, rural, interstate, missing or unknown.

GP caseload

The GP caseload was calculated by adding the number of claims for each GP provider and dividing into four groups based on consultation with GP’s on what was considered low and high caseloads for a provider. Group 1 with 13 claims per provider (c/p) were considered low, group 2 with 14 – 26 c/p was low-medium, group 3 with 27 – 48 c/p was high-medium and group 4 with 49+ c/p was considered a high caseload (over the eight year period from 2003-2010).

Occupation group

The major occupation group for the claimant based on the Australian and New Zealand Standard Classification of Occupations (ANZSCO).

Employer segment size

This variable reflects the size of the employer where the injury took place. The segment size is classified into four groups determined by the organisation’s annual remuneration; <$1 M (Small); $1 M - $20 M (Medium); >$20 (Large); Government (Government).

Industry group

The major workplace industry group code based on the Australian and New Zealand Standard Industrial Classification (ANZSIC) 2006 codes.

Socio-economic Index (SEIFA)

The “Index of Relative Socio-economic Advantage and Disadvantage (IRSAD) - 2011 State Score”, refers to a classification by the Australian Bureau of Statistics that ranks areas in Australia according to relative socio-economic advantage and disadvantage based on information from the five-yearly Census. All areas are ordered from the lowest (10 % assigned 1) to the highest (10 % assigned 10) decile number. Each area is divided into 10 groups and assigned a decile number, each decile subsequently then have an equal number of areas not necessarily people