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Table 3 Coefficients estimated with Prais-Winsten and Cochrane-Orcutt regression for the first-time prescription rate with various time periods in interrupted time series analysis model

From: Impact of a direct-to-consumer information campaign on prescription patterns for overactive bladder

Characteristics

Coefficient (95% Confidence Interval)b

Main analysisa

 Interrupted time period at Period 4 in Year 1

 β0: starting level of first-time prescription rate

471.9 (161.4 to 782.4)**

 β1: time

− 10.4 (− 51.3 to 30.5)

 β2: delayed effect of DTCI campaign (since Period 4 in Year 1)

1128.1 (181.7 to 2074.4)*

 β3: time × delayed effect of DTCI campaign

−77.6 (− 175.0 to 19.7)

 β1 + β3: post-intervention linear trend

− 88.1 (− 170.5 to −5.60)*

Sensitivity analysesa

Interrupted time period at Period 1 in Year 1

 β0: starting level of first-time prescription rate

506.5 (102.0 to 911.1)*

 β1: time

−18.4 (−94.8 to 58.0)

 β2: effect of DTCI campaign (since Period 1 in Year 1)

757.3 (− 149.4 to 1664.0)

 β3: time × DTCI campaign

−21.4 (− 129.1 to 86.3)

 β1 + β3: post-intervention linear trend

−39.8 (−99.0 to 19.4)

Interrupted time period at Period 2 in Year 1

 β0: starting level of first-time prescription rate

412.7 (−8.80 to 834.2)

 β1: time

10.7 (−62.4 to 83.8)

 β2: effect of DTCI campaign (since Period 1 in Year 1)

552.9 (−584.2 to 1690.0)

 β3: time × DTCI campaign

−54.4 (− 162.3 to 53.5)

 β1 + β3: post-intervention linear trend

−43.7 (− 120.3 to 32.9)

Interrupted time period at Period 3 in Year 1

 β0: starting level of first-time prescription rate

439.3 (114.0 to 764.5)*

 β1: time

−1.63 (−51.6 to 48.3)

 β2: effect of DTCI campaign (since Period 1 in Year 1)

846.6 (− 234.8 to 1927.9)

 β3: time × DTCI campaign

−62.2 (− 158.2 to 33.7)

 β1 + β3: post-intervention linear trend

−63.9 (− 145.9 to 18.2)

Interrupted time period at Period 5 in Year 1

 β0: starting level of first-time prescription rate

393.0 (−198.7 to 984.7)

 β1: time

12.6 (− 101.9 to 127.1)

 β2: delayed effect of DTCI campaign (since Period 4 in Year 1)

874.4 (− 1046.5 to 2795.4)

 β3: time × delayed effect of DTCI campaign

−106.2 (− 272.2 to 59.9)

 β1 + β3: post-intervention linear trend

−93.6 (− 227.2 to 40.0)

  1. *p < .05 **p < .01 ***p < .001
  2. aSample size, N1 of analyzed time periods = 30. The aggregated data samples were extracted from 1332 patients who were diagnosed with overactive bladder before May 2010 and who had not been prescribed a treatment drug during May 2010 to November 2010
  3. bCoefficients and 95% CIs were estimated for the first-time prescription rate per 5 weeks among a standardized 100,000 patients with overactive bladder who had not used the treatment drugs previously