Table BACKSIZE2 - 2004/05

Estimated prevalence and rates (%) of self-reported musculoskeletal disorders mainly affecting the back caused or made worse by current or most recent job, for small, medium and large workplaces, for people working in the last 12 months, 2004/05 and 2003/04

2004/05
2003/04

Workplace size +	Illness ascribed to their current/most recent job
	Sample cases	Estimated prevalence (thousands)			Rate per 100 employed in the last 12 months
		central	95% C.I.		central	95% C.I.
		central	lower	upper	central	lower	upper
Small (less than 50 employees) #	194	102	88	117	0.66	0.56	0.75
Medium (50-249 employees)	79	40	31	49	0.68	0.53	0.83
Large (250+ employees)	101	54	43	65	0.85	0.68	1.0
Missing/unknown	14	..	..	..	..	..	..
All persons	388	205	184	226	0.70	0.63	0.78

Notes:

Definitions and data reliability
.. Not applicable
# Includes those who are self employed on their own or with partners who have no employees
+ Relates to the number of people at their workplace, which is not necessarily the same as the number of people working for the company.
Individuals who gave the response 'Don't know but between 50 and 499' have been coded as missing/unknown.
See section 2.7 and Appendix 3.2 in the 'Self-reported work-related illness in 2004/05' (SWI04/05) report for more details on prevalence estimates and rates.
The estimates in this table take account of revisions made to the Great Britain population estimates following the 2001 Census.