Suitability of the lang II random dot stereotest for detecting manifest strabismus in 3-year-old children at child health centres in Sweden.

The aim of the study is to examine the suitability of the Lang II Random Dot Stereotest for use by district nurses in primary healthcare centres. The Lang Stereotest is an inexpensive method. It is easy to apply, but the child's co-operation is required. Approximately 100 district nurses were given detailed information and instruction by an orthoptist prior to a randomized population-based community trial initiated in 1993. In the county of Uppsala in Sweden, all 4293 children born in 1990 were randomized to one of the following four study groups: intervention, control, reliability or validity. All children were followed from birth to 6.5 y of age with respect to the occurrence of strabismus. The kappa statistic for test-retest reliability among district nurses was 0.65 (95% CI, 0.51-0.80). A validation of the outcomes of district nurses' against orthoptists' examinations using the Lang Stereotest showed a sensitivity of 0.33 (95% CI, 0.09-0.65) and a specificity of 0.85 (0.80-0.89). Of 113 cases of strabismus, 53% were detected within the first 3 y of life. Examination of 1132 3-y-old children using the Lang Stereotest enabled the district nurses to detect 11 new cases of strabismus. Only one of these cases was referred to an orthoptist as a direct consequence of the screening. The Lang Stereotest showed low reliability and low validity in this community trial. It is concluded that the Lang II Random Dot Stereotest is not suitable for the screening of manifest strabismus in unselected populations of 3-y-old children in Sweden, where a large proportion of cases of strabismus is detected during the first 3 y of life.

The causes of variations in unit labour costs: a preliminary study.

This paper reports a study of eight National Health Service Trusts, using data drawn from the Unit Labour Costs database and supplementary data collected for the purposes of the study, which set out to begin to explain the large variations in unit labour cost that exist. On the basis of extensive discussions within and between units, it was found that major causes of variations in productivity related to length of stay and bed utilization, which were in turn a result of variations in case mix. Staff utilization was a further major factor. Another observation was that the quality of data, particularly the integration of financial, activity and manpower data, was often poor.