. 2017 Aug 3;14(8):873. doi: 10.3390/ijerph14080873

Table 16.

Source Interventions (Type A).

Authors	Intervention & Study		N, Response Rate & Method	Exposure Levels		Change in Levels and Distribution of Change across Participants	Outcome Measure(s) before and after Outcomes	Did Outcome Change with Change in Exposure? Yes/No (Significance Tested?)	Before/after Outcome Change Compared to That Estimated from an ERF	Comments	Confounders Adjusted for in Analyses
Authors	Nature	Design	N, Response Rate & Method	Before	After		Outcome Measure(s) before and after Outcomes			Comments	Confounders Adjusted for in Analyses
Möhler et al. (1997) [51]	Germany Rail grinding to reduce railway noise emissions	B and two A. 1 mo. B; 1mo A. 3^rd round was 1 year after 2^nd round	B. 81 A. 64 A2. 46 questionnaire	L_dn 55–75 Calculated, with some measurement	L_dn 50–65	−7 to −8 dB Distribution of change across Ps not reported	0–10 total annoyance scale Reported as mean annoyance scores for group Difference in mean reported	Yes Difference between B & A = 0.6 (t = 2.07, df = 63, p < 0.05) Difference between B & A2 = 0.8 (t = 2.26, df = 45, p < 0.05) No difference between A1 & A2	n.a.