Disparities in Spatial Prevalence of Feline Retroviruses due to Data Aggregation: A Case of the Modifiable Areal Unit Problem
Table 4
(a) Results from multivariable spatial Poisson regression modeling of potential risk factors for FeLV infection at three spatial aggregation levels (postal code, county, and state levels). (b) Results from multivariable spatial Poisson regression modeling of potential risk factors for FIV infection at three spatial aggregation levels (postal code, county, and state levels).
(a)
Postal code
value
County
value
State
value
PRa (95% CI)
PRa (95% CI)
PRa (95% CI)
% juvenile
≤50
Ref
Ref
Ref
>50
0.66 (0.52–0.84)
<0.01
0.78 (0.65–0.94)
<0.01
0.74 (0.5–1.08)
0.13
% female intact
≤50
Ref
Ref
Ref
>50
1.25 (0.97–1.61)
0.09
1.18 (0.96–1.45)
0.12
0.63 (0.36–1.09)
0.10
% male intact
≤50
Ref
Ref
Ref
>50
1.05 (0.82–1.35)
0.69
0.88 (0.72–1.07)
0.19
2.06 (1.12–3.77)
<0.05
% indoors
≤50
Ref
Ref
—
—
>50
0.62 (0.48–0.81)
<0.01
0.8 (0.63–1.02)
0.07
—
—
% healthy
≤50
Ref
Ref
—
—
>50
0.99 (0.74–1.32)
0.93
1.07 (0.82–1.4)
0.63
—
—
% tested at clinics
≤50
Ref
Ref
Ref
>50
1.79 (1.34–2.39)
<0.01
1.26 (1.04–1.54)
0.02
1.29 (0.86–1.92)
0.22
FIV seroprevalence
<3.0
Ref
Ref
Ref
3.0–8.0
1.42 (1.12–1.80)
<0.01
1.17 (0.98–1.4)
0.08
1.11 (0.78–1.57)
0.55
>8.0
2.44 (1.80–3.33)
<0.01
2.4 (1.87–3.09)
<0.01
2.6 (1.27–5.32)
<0.05
Intercept: −4.86, −3.86, and −3.99 for postal code, county, and state levels respectively, with a value of <0.01.
aPrevalence ratios obtained by exponentiation of respective coefficients and their 95% confidence intervals. Rate/risk ratios are interpreted as prevalence ratios.
(b)
Postal code
value
County
value
State
value
PRa (95% CI)
PRa (95% CI)
PRa (95% CI)
% juvenile
≤50
Ref
Ref
Ref
>50
0.76 (0.56–1.02)
0.07
0.91 (0.71–1.16)
0.44
0.83 (0.57–1.21)
0.35
% female intact
≤50
Ref
Ref
Ref
>50
0.73 (0.53–0.99)
0.04
0.77 (0.59–1)
0.05
0.94 (0.55–1.62)
0.83
% male intact
≤50
Ref
Ref
Ref
>50
0.98 (0.71–1.34)
0.89
1.01 (0.78–1.3)
0.96
0.88 (0.48–1.59)
0.67
% indoors
≤50
Ref
Ref
—
—
>50
1.03 (0.72–1.48)
0.87
0.85 (0.58–1.24)
0.39
—
—
% healthy
≤50
Ref
Ref
—
—
>50
1.08 (0.73–1.60)
0.70
0.85 (0.61–1.2)
0.36
—
—
% tested at clinics
≤50
Ref
Ref
Ref
>50
1.03 (0.77–1.39)
0.84
1.46 (1.13–1.89)
<0.01
1.23 (0.85–1.76)
0.28
FeLV seroprevalence
<3.0
Ref
Ref
Ref
3.0–8.0
1.57 (1.17–2.11)
<0.01
1.29 (1.02–1.63)
0.04
1.18 (0.82–1.69)
0.38
>8.0
2.30 (1.60–3.29)
<0.01
2.01 (1.44–2.81)
<0.01
5.19 (1.16–23.25)
0.04
Intercept: −3.40, −3.30, and −3.39 for postal code, county, and state levels respectively, with a value of <0.01.
aPrevalence ratios obtained by exponentiation of respective coefficients and their 95% confidence intervals. Rate/risk ratios are interpreted as prevalence ratios.
