Table 1.
Summary Characteristics of the Reviewed RCT Studies
| Study ID | Ns | Age | % female | Country | Type meditation | Ss | Type of control | Anxiety measure | Grp or Ind | Home- work | Duration (wks) | # Sessions | Ret rate % | CLEAR score | Main Findings on Anxiety (anx) | Notes |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Banerjee et al. (2007) 77 | 68 | 44 | 85 | India | Yoga | 2 | ATT | HADS | Both | Y | 6 | 6 | 85 | 0.55 | The yoga gp had a sig decrease in anx after 6 weeks; the control gp did not. The difference in changes b/n gps was significant (p<.001). | Breast cancer |
| Branstrom et al. (2010) 13 | 71 | 52 | 99% | Sweden | MM | 2 | WL | HADS | Grp | Y | 8 | 8 | 83 | 0.89 | There was no sig difference of change in anxiety b/n MM gp and control. | Cancer |
| Carson et al. (2010) 51 | 53 | 54 | 100 | USA | Yoga | 2 | WL | FIQR | Ind | Y | 8 | 8 | 82 | 0.82 | Yoga gp had a sig greater decrease in anx as compared to WL control (p=.0407, ES=1.28) | Fibromyalgia |
| Davidson et al. 2003 52 | 41 | 36 | 71 | USA | MBSR | 1 | WL | STAI | Both | Y | 8 | 8 | 100 | 0.64 | More decrease of anx in MBSR gp as compared to control (p < 0.05) | Healthy |
| Foley et al. (2010) 53 | 115 | 55 | 77 | Australia | MBCT | 2 | WL | HAM-A | Both | Y | 10 | 8 | 93 | 1.0 | The MBCT gp had sig more improvement in anx as compared to WL (ES= .59 for pre-post) | Cancer |
| Frye et al. (2007) 54 | 84 | 69 | 64 | USA | Tai Chi | 1 | WL & AA | STAI | Grp | N | 12 | 36 | 82 | 0.64 | Both exercise and Tai Chi gps demonstrated decreased anx over 12 weeks (p<.01) but there was no sig difference b/n gps | Elderly population |
| Gonzales et al. (2010) 55 | 44 | 34 | 40 | USA | GI | 2 | WL | VAS | Ind | N | 1 day | 1 | 100 | 0.89 | Significant more decrease in anx in GI gp after one session (p=.002) as compared to WL control | Head/neck surgery |
| Gross et al. (2010) 26 | 150 | 53 | 45 | USA | MBSR | 2 | ATT | STAI | Both | Y | 26 | 9 | 92 | 0.82 | MM gp had more decrease in anx (p<.001) at 8 wks as compared to control. Tx effects were sustained at 1 year follow-up (p<.01;ES=.56). | Solid organ transplant |
| Gross et al. (2011) 84 | 30 | 50 | 73 | USA | MBSR | 2 | AA | STAI | Both | Y | 8 | 9 | 90 | 0.9 | Anxiety scores decreased in both gps but no sig difference b/n gps | Chronic insomnia |
| John et al. (2007) 78 | 72 | 34 | 68 | India | Yoga | 2 | ATT | HADS | Both | Y | 12 | 72 | 90 | 0.64 | The yoga gp demonstrated a sig drop in anx (p=.001) while an increase of anx in control gp. | Migraine without aura |
| Kabat-Zinn et al. (1998) 56 | 37 | 43 | 54 | USA (US) | MBSR | 2 | WL | STAI | Ind | N | 13 | 13 | 62 | 0.82 | There was no significant difference b/n the mindfulness and control gps on STAI. | Psoriasis |
| Kondwani et al. (2005) 79 | 34 | 50 | 56 | USA | TM | 2 | ATT | MHI | Both | Y | 52 | 19 | 81 | 0.8 | TM gp had a decrease in anx over time (p=.02) & a sig more decrease in anx as compared to the control (p=.03) | Hypertension |
| Kozasa et al (2008) 57 | 22 | 43 | 91 | Brazil | Yoga | 3 | WL | STAI | Grp | Y | 4 | 2 | unc | 0.30* | Yoga group showed more sig decrease in anxiety after treatment (sig level not available) | anxiety disorders |
| Lengacher et al. (2009) 58 | 84 | 58 | 100 | USA | MBSR | 2 | WL | STAI | Both | Y | 6 | 6 | 98 | 0.91 | Mindfulness gp had significantly more decreased anx compared to the control gp (state anx p=.03, trait anx p=.004) | Breast Cancer |
| Leon-Pizarro (2007) 59 | 66 | 24–82 | 100 | Spain | GI | 3 | WL | HADS | Ind | Y | 4 | 3 | 70 | 0.55* | GI gp showed a significant more decrease in anx (p=0.008) as compared to control. | Gyn/breast brachy-therapy |
| Li et al. (2002) 60 | 86 | 32 | 0 | China | Qigong | 2 | WL/AA | HAM-A | Grp | N | 1.5 | daily | 100 | 0.7 | Qigong (p<.001) and medicine (p<.05) gps had sig greater decrease in anx as compared to control. Qigong gp had more reduction than medicine gp (p<.001). | Heroin addicts |
| Ljotsson et al. (2010) 80 | 85 | 35 | 84 | Sweden | MBSR | 2 | ATT | VSI | Ind | Y | 10 | daily | 95 | 0.71 | Mindfulness gp had a significant more decrease in gastrointestinal-related anx (p<.001, ES 0.64) as compared to the WL | IBS |
| Malathi & Damodaran (1999) 61 | 50 | 18.5 | unc | India | Yoga | 1 | WL | STAI | Grp | N | 12 | 36 | 100 | 0.45* | On the day of the exam and after yoga session, there was a more sig reduction in anx in yoga gp as compared to control gp (p<0.001) | Med students |
| Manzaneque et al. (2009) 62 | 39 | 18–21 | 87 | Spain | Qigong | 1 | WL | STAI, BAI | Grp | Y | 4 | 20 | 85 | 0.73 | Qigong gp had a significant more decrease in anx after 1 month (p<.01) on STAI as compared to control. No change on Beck Anx Inventory | Healthy Ss |
| McMillan et al. (2002) 63 | 130 | 34 | 22 | UK | MBSR | 2 | WL & AA | HADS | Both | Y | 4 | 5 | 85 | 0.64 | No significant differences of change were found on anx scores b/n the MM gp and the physical exercise and WL control gps | TBI |
| Moffatt et al. (2010) 64 | 69 | 33 | 100 | Canada | GI | 2 | WL | STAI | Ind | N | 4 | 8 | 87 | 1.0 | No significant differences in change b/n the GI and WL control gps but pts reported positively for their GI experience | Pregnant hbp |
| Nidich et al. (2009) 65 | 298 | 26 | 61 | USA | TM | 1 | WL | POMS | Ind | Y | 12 | 13 | 69 | 0.89 | The TM gp showed significant more improvement in anx at 3 month follow up (p=.003) as compared to the WL control. | College students |
| Nunes et al. (2007) 66 | 34 | 52 | 100 | Brazil | GI | 2 | WL | BAI & STAI | Grp | Y | 4 | 24 | 100 | 0.73 | The GI group had significant more decrease in state anx(p<.05; ES 0.52) and trait anx (p<.001; ES 0.79) as compared to control | Breast cancer |
| Oken et al. (2004) 67 | 69 | 49 | 77 | USA | Yoga | 2 | WL & AA | STAI | Both | Y | 24 | 24 | 83 | 0.8 | No significant difference in change b/n yoga gp and exercise or WL control gps on anx measure. | Multiple sclerosis |
| Rao et al. (2009) 81 | 70 | 30–70 | 100 | India | Yoga | 2 | ATT | STAI | Ind | Y | 24 | 22 | 54 | 0.73 | Greater decrease in anx (p<.001) among yoga gp than control post-surgery, post-radiation (p<.01) & post-chemotherapy (p<.001). | Breast cancer |
| Schmidt et al. (2010) 68 | 177 | 53 | 100 | Germany | MBSR | 2 | WL & AA | STAI | Both | Y | 8 | 9 | 82 | 0.91 | AA gps showed more decrease in anx as compared to control (p=0.004) but no significant difference b/n MBSR and active control. | Fibromyalgia |
| Shapiro (1998) 69 | 200 | n/a | n/a | USA | MBSR | 1 | WL | STAI | Both | Y | 8 | 8 | 97 | 0.73 | The mindfulness gp showed a significant more decrease in both state anx (p<.05) and trait anx (p<.002) as compared to control | Med Student Stress |
| Sheppard et al. (1997) 86 | 44 | 50.5 | 15 | USA | TM | 1 | AA | STAI | Both | Y | 12 | 13 | 73 | 0.64 | The TM gp showed more decrease in anx at 3mos (p<0.05) as compared to control and this pattern continued at 3 yr follow up.. | Healthy |
| Sloman et al. (2002) 70 | 56 | 27–79 | 46 | Israel | GI | 3 | WL | HADS | Ind | N | 4 | 4 | 100 | 0.8 | No significant decrease in anx for GI gp (p=0.57) as compared to control. | Cancer |
| Smith et al. (2007) 85 | 131 | 44 | 83 | Australia | Yoga | 1 | AA | STAI | Grp | N | 10 | 10 | 90 | 0.82 | Yoga gp had more improvement on mental health. But no sig differences b/n gps on the STAI | Healthy |
| Speca et al. (2000) 71 | 109 | 51 | 79 | Canada | MBSR | 2 | WL | POMS | Both | Y | 7 | 7 | 83 | 0.73 | MBSR had sig more decreased anxiety after intervention as compared to the control (p<0.001) | Cancer |
| Stein et al. (2010) 72 | 56 | 66 | 30 | USA | GI | 3 | WL & AA | HADS; POMS | Ind | Y | 24 | 1 | 100 | 0.67 | There was no sig difference b/n gps on anx measures but participants reported liking GI. | Coronary Bypass |
| Stenlund et al. (2009) 73 | 82 | 44 | 83 | Sweden | Qigong | 2 | WL | HADS | Grp | Y | 12 | 24 | 82 | 0.67 | No difference in anx levels b/n gps; both improved significantly on anx over time | Burnout |
| Tacon et al. (2003) 28 | 18 | 61 | 100 | USA | MBSR | 2 | WL | STAI | Both | Y | 8 | 8 | 90 | 0.58 | The mindfulness gp showed a significant more decrease in anx (p<.01) and there was no change in the control gp. | Heart Disease |
| Taneja et al. (2004) 74 | 22 | 35 | 0 | India | Yoga | 2 | WL | STAI | Ind | Y | 8 | 1 | 95 | 0.55 | At 1 month there was a more sig decrease in anxiety in yoga gp as compared to control (p<0.01), but not so at 2 months. Overall p < .05. | IBS |
| Tsai et al. (2003) 75 | 88 | 52 | 43 | Taiwan | Tai Chi | 2 | WL | STAI | Grp | N | 12 | 36 | 86 | 0.7 | Tai Chi gp showed a sig more decrease in anx (both state & trait p<.01) as compared to control. | Hypertension |
| Vadiraja et al. (2009) 82 | 88 | 47 | 100 | India | Yoga | 2 | ATT | HADS | Ind | Y | 6 | 18–24 | 89 | 0.6 | Both the yoga gp and the supportive therapy control gp decreased in anx scores but there was a significant difference b/n the gps (p<.001). | Breast cancer |
| Wang et al. (2010) 39 | 34 | 77 | 55 | Japan | Tai Chi | 2 | AA | GHQ-A | Grp | N | 12 | 12 | 85 | 0.58* | Tai Chi gp showed a significant more reduction in anx (p=.034) as compared to the control. | Stroke |
| Williams et al. (2008) 76 | 68 | 18–65 | 47 | UK | MBSR | 4 | WL | BAI | Both | Y | 8 | 8 | 81 | 0.8 | Mindfulness gp had lower anx than the control gp (p=.014) for bipolar pts, but no for unipolar pts. | Bipolar Disorder |
| Wu et al. (1999) 83 | 26 | 38 | 73 | USA | Qigong | 2 | ATT | CSAQ | Ind | Y | 10 | 6 | 85 | 0.6 | Qigong gp had greater anx reduction than control gp over time (p<.01) but no sig difference b/n gps. | Pain |
Note: Type of subjects (Ss): 1= healthy subjects; 2 = patients with health problems & anxiety symptoms; 3 = patients with anxiety disorders; 4 = Mixed.
Type of control: WL= Waiting list or treatment as usual; ATT=attention/education control; AA=alternate active therapy
Type of Meditation: MM = Mindfulness; MBSR=mindfulness-based stress reduction; TM=transcendental meditation; GI=guided imagery; MBCT=mindfulness-based cognitive therapy
Anxiety Measure: STAI = (Spielberg) State-Trait Anxiety Inventory; HAM-A=Hamilton Anxiety sale; HADS = Hospital anxiety and depression scale; BAI = Beck Anxiety Inventory; GHQ-A = General Health Question – Anxiety
Other abbreviations: Ss = Subjects; gp=group; Anx= Anxiety; tx = treatment; b/n = between; Pts=participants; ES=effect size; Ret = retention; unc = unclear;
*
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