Improving the measurement of neighbourhood characteristics through systematic observation: inequalities in smoking as a case study.

Systematic observation is increasingly used as a method to measure neighbourhood characteristics thought to influence health inequalities. This article reports on the theory-driven development of a new observation tool composed of reflective indicators of neighbourhood characteristics believed to influence inequalities in smoking. We also report the results of generalisability analyses conducted to estimate the reliability (inter-rater reliability and temporal stability) of the observation tool. We use the reliability results to reflect on the quality of the measures and on the theoretical anchors of the tool. We conclude by making recommendations to improve measures collected through systematic observation.