TABLE 4.
Methodological Comparisons to Currently Published Literature
| Author/Year | Analysis Period | Index Date | ICD-9-CM Diagnosis Codes to Identify MDD | TRD Case Definition | Observation Period Definition | Multivariate Analysis | |||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| TRD ID Period | Number of Failed Courses of Depression Therapy | Adequate Duration | Adequate Dose | TRD Scale and Matrix Criteria | MGH TRD Staging Method | ||||||
| Current approach | 10/2008-9/2016 | TRD cohort: Third-line initiation Non-TRD cohort: Simulated index date based on the TRD cohort’s third-line initiation date | 296.2x, 296.3x, 300.4, 309.0, 309.1, or 311 | A variable period of ≤360 days following first-line antidepressant initiation | ≥ 2 | ≥ 44 days within 2 consecutive 30-day segments | 12-month period following index date | PSM | |||
| Amos 20188 | 7/2009-3/2015 | First observed antidepressant that occurred after ≥ 6 months without an antidepressant | 296.2x or 296.3x and 296.2x, 296.3x, 300.4x, 311.x, 309.0x, or 309.1x at least 6 months before or after the antidepressant fill date starting January 2010 | Index date to the earliest of 2 years following the first antidepressant, end of continuous eligibility, or end of data availability | ≥ 2 | ≥ 6 weeks without gaps of longer than 14 days | ✓ | Same as TRD ID period | PSM (TRD vs. non-TRD MDD; TRD vs. no MDD) OLS regression to estimate adjusted costs | ||
| Olfson 20189 | 1/2008-7/2014 | First observed antidepressant that occurred after ≥6 months without an antidepressant | 296.2, 296.3, 300.4, 311, 309.0, or 309.1 within 30 days before or after the index antidepressant prescription fill and 296.2x or 296.3x during the 12 months before or after the index antidepressant fill | First 12-month period following the index date | > 2 | >6 weeks without gaps of longer than 14 days | ✓ | Adjacent 12-month period following the TRD ID period | 2-part model to estimate adjusted costs (first part: logistic regression; second part: GLM with gamma distribution and log link) | ||
| Olchanski 201310 | 1/2001-12/2009 | Not specified | 296.2x, 296.3x, 300.4, 309.0, 309.2x, or 311 | ≥2-year period of continuous treatment for MDD | ≥ 4 | ≥ 12 weeks | Same as TRD ID period | Log-linear regression model to estimate adjusted costs | |||
| Ivanova 201016 | 1/1999-12/2007 | First observed antidepressant on or after 1/1/2004 | 296.2x or 296.3x | 2-year period following the index date | ≥2 | ≥6 weeks | ✓ | ✓(alternative approach) | Same as TRD ID period | Matching (type not specified) GLM to estimate adjusted costs | |
| Gibson 201011 | 1/2000-12/2007 | First observed antidepressant | 296.2x, 296.3x, 300.4, 309.0, or 311 | 2-year period following the index date | ✓ | Adjacent 12-month period following the TRD ID period | PSM GLM to estimate adjusted costs | ||||
| Russell 200417 | 1/1995-12/2000 | Date patients met all criteria for TRD | 296.2x, 296.3x, 296.5x, 296.6x, 296.89, 300.4, 309.0, 309.1, or 311 | Entire study window | ≥2 or >1 plus a depression-related hospitalization, ECT, or a suicide attempt | ≥4 weeks | ✓ | Index date to the time of each subsequent depression medication regimen change | Negative binomial regression model to estimate the number of antidepressant regimen changes | ||
| Greenberg 200418 | 1/1996-12/1998 | Not specified | 296.2x, 296.3x, 300.4, 309.0, 309.2x, or 311 | 1996-1998 | ✓ | 1998 | None | ||||
| Corey-Lisle200212 | 1/1996-12/1998 | Not specified | 296.2x, 296.3x, 300.4, 309.0, 309.2x, or 311 | 1996-1998 | ✓ | 1998 | None | ||||
| Crown200219 | 1/1995-6/2000 | Hospitalized cohort: day following hospital discharge and/or suicide attempt Outpatient cohort: day following the dispensing of the third antidepressant | 296.2x, 296.3x, 296.5x, 296.6x, 296.89, 300.4, 309.0, 309.1, or 311 | Time from first antidepressant to the index date | Hospitalized TRD cohort: ≥1 plus a depression-related hospitalization or suicide attempt Outpatient TRD cohort: ≥2 but were not hospitalized | ≥8 weeks | ✓ | Index date through the last available medical claim (≥9 months) | OLS regression to estimate adjusted costs | ||
ECT=electroconvulsive therapy; GLM=generalized linear model; ICD-9-CM=International Classification of Diseases, Ninth Revision, Clinical Modification; ID=identification; MDD=major depressive disorder; MGH=Massachusetts General Hospital; OLS=ordinary least squares; PSM=propensity score matching; TRD=treatment-resistant depression.