Table 1.
Inclusion criteria, outcomes, and moderators in previous meta-analyses and the current study.
| Meta-analysis | Nr of studies included | Inclusion criteria | Design of the included studies | Outcomes | Moderators |
|---|---|---|---|---|---|
| Current meta-analysis | 20 | - Executive coaching matched Kilburg's (1996) definition | RCT | - Behaviors Cognitive activities Leadership Performance | - Number of coaching sessions - Length of coaching program (weeks) |
| - External coach | - Attitudes Organization People Job/Task | ||||
| - Randomized control trial | - Person characteristic States Traits | ||||
| - Sufficient statistics reported | |||||
| Burt and Talati (2017) | 11 | - Coaching method design equivalent to Grant's (2003) definition | RCT | - Attitudes | -Participant gende |
| - External coach | - Coping | ||||
| - Randomized control trial | - Self-regulation | ||||
| - Outcomes reported | - Well-being | ||||
| - Sufficient statistics reported | |||||
| Jones et al. (2016) | 17 | - Workplace coaching | RCT | - Affective outcomes | - Research design |
| - Within- and between-subjects designs | QEF | - Skill-based outcomes | - Multisource feedback | ||
| - Report sample sizes | WSD | - Individual level outcomes | - Format of coaching | ||
| -Reported statistics | - Type of coach (internal or external) | ||||
| - Coaching outcome measured at individual level | - Number of coaching sessions | ||||
| Sonesh et al. (2015) | 24 | - Leadership, business, or executive coaching | RCT | - Relationship outcomes | - Sample type |
| - Empirical studies | QEF | Generic coach–coachee relationship | - Design type | ||
| WSD | Working alliance | - Coach background | |||
| - Coachee outcomes | - Coach expertise | ||||
| Goal attainment | - Number of coaching sessions | ||||
| Behavioral change | |||||
| Work-related attitude change | |||||
| Personal attitude change | |||||
| Improved relations with others | |||||
| Overall satisfaction with coaching | |||||
| Cognitive change | |||||
| Task performance | |||||
| - Organization outcomes | |||||
| Theeboom et al. (2014) | 18 | - External professional trained coach | RCT | - Performance/skills | - Study design |
| - Studies conducted in a work or educational context | QEF | - Work attitude | - Number of coaching sessions | ||
| - Coaches belonged to a non-clinical population | WSD | - Coping | |||
| - No influence of other interventions | - Self-regulation | ||||
| - Enough statistical information | - Wellbeing | ||||
| - Included quantitative data | |||||
| De Meuse et al. (2009) | 12 | - Executive coaching | QEF | - Reactions to coaching | - Type of coaching provided (suggested) |
| - External coach | WSD | - Coaching effectiveness at individual level | - Content of the coaching engagement (suggested) | ||
| - Pre- and post-coaching ratings | - Coaching impact at organizational level | - Content of the coaching engagement (suggested) | |||
| - Statistics reported in the article | |||||
RCT, randomized control trial; QEF, quasi-experimental field study in which participants were non randomly allocated to experimental and control groups; WSD, within-subjects design without control group, which includes both pre- and post-intervention measures.