eight weeks; he had suffered from two years of lower back pain when he first came a year ago. He has no discomfort now after 8 chiropractic treatments, but is aware that danger lurks.

11. Mrs C has been having severe headaches, and taking a lot of analgesics. It's a non complicated upper cervical facet syndrome, and she's doing well.

12. Mr D is a 38 old year man with chronic shoulder pain after a rotator cuff tear playing cricket. It responded well to treatment, but he knows he must do his exercises every day; for two years he couldn't sleep on that shoulder.

13. Mr D, a 71 year old man, has a severe ache in the shoulder and midback
since working above his head. Trapped nerve tests are negative butThe National Population Registry, the Norwegian Health Economics Administration Database (HELFO), the GPs' database, and the 2008 Medical Birth Registry.

All Norwegian citizens and legal immigrants residing in Norway for over 6 months have a unique personal identification number and this was used to link the four registries. All legally registered immigrants are members of the National Insurance Scheme, which entitles them access to a GP and Emergency Primary Care services. All nonimmigrant women with both parents from Norway (1 168 832) and immigrant women defined as born abroad with both parents from abroad (152 800) in the age group for CCS (25--69 years) registered in Norway in 2008 were included in the study.

From the National Population Registry, we obtained information on study women in terms of age, immigration category (nonimmigrant or