The spatial distribution of radiodense breast tissue: a longitudinal study

Breast Cancer Research

Table 2 Determinants of spatial autocorrelation in density

Number of women	Number of observations	Correlate of density	Categories	Change in Moran's I value from baseline^a	P value^b
165	493	Parity	0	Baseline	0.14
			1	0.04 (0.00, 0.07)
			2	0.01 (-0.01, 0.04)
			3+	0.03 (-0.00, 0.06)
162^c	484	Body mass index (kg/m²)	≤ 21.5	Baseline	0.03
			> 21.5 to ≤ 24.1	-0.02(-0.04, 0.00)
			> 24.1 to ≤ 27.0	-0.01(-0.03, 0.01)
			> 27.0	-0.04(-0.07, -0.01)
138^d	413	Age at first birth (years)	≤ 23	Baseline	0.25
			> 23 to ≤ 27	0.01 (-0.02, 0.03)
			> 27 to ≤ 30	0.01 (-0.01, 0.04)
			> 30	-0.01(-0.04, 0.01)

^aChange (95% confidence interval) estimated by regressing Moran's I value onto correlates of density while adjusting for overall breast density and clustering at the woman level. ^bWald's test. ^cBody mass index missing for three women. ^dAmong parous women only.

ISSN: 1465-542X