Table 1.
Joinpoint analysis: Identifying changes in the incidence and prevalence of gabapentinoid prescribing over time.
| Outcomes by gabapentinoid prescribing | Joinpoint | Start | End | APC/MPC (95% CI) | Test Statistic (t) | p-value |
|---|---|---|---|---|---|---|
| Incidence (annual) | ||||||
| Gabapentin | 0 | 1997–98 | 1999–20 | 164.2 (−2.4 to 614.8) | 2.2 | 0.055 |
| Gabapentin | 1 | 1999–20 | 2003–04 | 52.0 (12.1–106.0) | 3.1 | 0.012 |
| Gabapentin | 2 | 2003–04 | 2013–14 | 13.6 (12.4–14.8) | 26.3 | <0.001 |
| Gabapentin | 3 | 2013–14 | 2016–17 | 4.7 (−4.5 to 14.7) | 1.1 | <0.001 |
| Gabapentin | 4 | 2016–17 | 2019 | −13.4 (−18.5 to −7.9) | −5.3 | 0.010 |
| Pregabalin | 0 | 2004–05 | 2010–11 | 19.0 (12.0–26.5) | 6.3 | |
| Pregabalin | 1 | 2010–11 | 2019 | 3.4 (1.0–5.9) | 3.1 | |
| Incidence (monthly) | ||||||
| Gabapentin | 0 | October-17 | September-19 | −1.5 (−1.9 to −1.0) | −6.3 | <0.001 |
| Pregabalin | 0 | October-17 | January-19 | 0.5 (−0.5 to 1.4) | 1.0 | 0.326 |
| Pregabalin | 1 | January-19 | September-19 | −3.4 (−5.6 to −1.1) | −3.1 | 0.005 |
| Prevalence (annual) | ||||||
| Gabapentin | 0 | 1997–98 | 2001–02 | 127.5 (93.2–167.9) | 11.4 | <0.001 |
| Gabapentin | 1 | 2001–02 | 2005–06 | 36.6 (29.6–43.6) | 14 | <0.001 |
| Gabapentin | 2 | 2005–06 | 2013–14 | 15.6 (14.8–16.4) | 47.9 | <0.001 |
| Gabapentin | 3 | 2013–14 | 2016–17 | 7.2 (3.6–11.0) | 4.6 | 0.001 |
| Gabapentin | 4 | 2016–17 | 2019 | −0.6 (−2.2 to 1.0) | −0.9 | 0.407 |
| Pregabalin | 0 | 2005–06 | 2009–10 | 41.7 (29.5–55.0) | 9.2 | <0.001 |
| Pregabalin | 1 | 2009–10 | 2014–15 | 16.5 (11.6–21.6) | 8.4 | <0.001 |
| Pregabalin | 2 | 2014–15 | 2019 | 3.1 (0.7–5.5) | 3.1 | 0.017 |
| Prevalence (monthly) | ||||||
| Gabapentin | 0 | October-17 | January-18 | −0.2 (−0.5 to 0.1) | −1.5 | 0.166 |
| Gabapentin | 1 | January-18 | September-18 | 0.1 (0.1–0.2) | 4.1 | 0.001 |
| Gabapentin | 2 | September-18 | July-19 | −0.2 (−0.3 to −0.2) | −9.7 | <0.001 |
| Gabapentin | 3 | July-19 | September-19 | −2.4 (−2.9 to −1.8) | −8.7 | <0.001 |
| Pregabalin | 0 | October-17 | February-18 | 0.0 (−0.2 to 0.3) | 0.1 | 0.907 |
| Pregabalin | 1 | February-18 | September-18 | 0.5 (0.3–0.6) | 7.5 | <0.001 |
| Pregabalin | 2 | September-18 | July-19 | 0.0 (−0.1 to 0.0) | −0.9 | 0.404 |
| Pregabalin | 3 | July-19 | September-19 | −4.2 (−5.0 to −3.4) | −11.6 | <0.001 |
APC: annual percent change; CI: confidence interval; MPC: monthly percent change.