Assessing the precision of a time-sampling-based study among GPs: balancing sample size and measurement frequency

Table 2 Means and one-sided CIs of GPs’ working hours, total and by position of employment and gender (based on the SMS measurements taken once every 3 h during 1 week for every GP)

	Number of measurements	Number of GPs	Mean hours	CI ± hours
Total^a	58 856	1 051	45.18	0.67
Self-employed
Male	16 296	291	51.91	1.32
Female	18 312	327	45.81	1.20
Salaried
Male	3 136	56	41.57	2.81
Female	8 232	147	32.16	1.63
Locum
Male	5 096	91	36.96	2.14
Female	7 784	139	33.13	1.68

The CI includes sample fluctuation and measurement fluctuation, as has been described in the “Methods” section
CI one-sided 95% confidence interval, hours above or below the mean
^aMean hours and CIs are weighted by position of employment and gender of the population of GPs

ISSN: 1478-4491