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Table 4 Multivariate GEE regression models of testing intervals and of probability of >9 and >6 months between viral load measurements

From: Regional differences in rates of HIV-1 viral load monitoring in Canada: Insights and implications for antiretroviral care in high income countries

 

Interval (days) between successive tests

Probability of an interval >9 months

Probability of an interval >6 months

Covariates

Estimate (95% CI)

p value

Odds Ratio (95% CI)

p value

Odds Ratio (95% CI)

p value

Intercept

125.8 (118.8, 132.9)

< .0001

0.09 (0.07, 0.11)

< .0001

0.20 (0.16, 0.23)

< .0001

Region

      

   Quebec

20.3 (15.5, 25.0)

< .0001

1.72 (1.39, 2.14)

< .0001

1.61 (1.37, 1.89)

< .0001

   Ontario

18.7 (14.3, 23.0)

< .0001

1.78 (1.37, 2.31)

< .0001

1.77 (1.47, 2.14)

< .0001

   BC

0

 

1

 

1

 

Age (per 10 years)

-3.8 (-5.4, -2.2)

< .0001

0.77 (0.70, 0.85)

< .0001

0.77 (0.72, 0.83)

< .0001

Risk factor

      

   MSM

-9.2 (-13.1, -5.4)

< .0001

0.62 (0.49, 0.78)

< .0001

0.66 (0.56, 0.77)

< .0001

   IDU

16.0 (11.1, 20.9)

< .0001

1.68 (1.38, 2.05)

< .0001

1.71 (1.48, 1.99)

< .0001

Year of initiating cART

      

   >2004

-15.8 (-21.9, -9.7)

< .0001

0.62 (0.46, 0.83)

0.001

0.74 (0.60, 0.91)

0.005

   2001-2004

-12.4 (-18.2, -6.6)

< .0001

0.70 (0.57, 0.86)

0.0006

0.75 (0.64, 0.89)

0.0007

   2000 (ref.)

0

 

1

 

1

 

1st year of cART

-24.3 (-26.0, -22.6)

< .0001

0.15 (0.12, 0.20)

< .0001

0.32 (0.29, 0.36)

< .0001

On cART at current visit

-27.8 (-31.0, -24.6)

< .0001

0.34 (0.29, 0.40)

< .0001

0.40 (0.36, 0.45)

< .0001

VL < 50 copies/mL at previous test

8.6 (6.6, 10.7)

< .0001

0.56 (0.48, 0.65)

< .0001

0.90 (0.82, 0.98)

0.02

Boosted PI based cART

-9.1 (-12.2, -6.0)

< .0001

  

0.82 (0.71, 0.94)

0.006

AIDS defining illness

-4.9 (-8.5, -1.4)

0.007

    
  1. MSM = men who have sex with men, IDU = injection drug use, cART = combination antiretroviral therapy, VL = viral load, PI = protease inhibitor,.