the course of low back pain in general practice: a one year follow up study. Ann Rheum Dis 1998;57:13-9. 16 Croft PR, Papageorgiou AC, Ferry S, Thomas E, Jayson MIV, Silman AJ. Psychological distress and low back pain: Evidence from a prospective study in the general population. Spine 1996;20:2731-7. 17 Papageorgiou AC, Macfarlane GJ, Thomas E, Croft PR, Jayson MIV, Silman AJ. Psychosocial fact...

In this paper, a regression type estimator representing a class of estimators is proposed to estimate the population mean of the study variable. The bias and mean square error of the proposed estimator are obtained. Also the optimizing value of the unknown parameter is derived and the expression of minimum mean square error is obtained. Further since the proposed estimator is biased, a jackknif...