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Table 6 Reported construct validity of GAS in included studies

From: A systematic review to investigate the measurement properties of goal attainment scaling, towards use in drug trials

First author Year Drug study N Methods and results Quality
Cusick 2006 Yes 41 Correlations with COMP and GAS Likert scale were measured; no correlation higher than −0.25 or with a p-value lower than 0.05. +/−
No hypotheses
De Beurs 1993 Yes 40 Correlations with agoraphobia, rating of treatment outcome by therapist, M-BAT, depression and somatic anxiety were measured; GAS has a high correlation with gain scores on agoraphobia (0.63), rating of treatment outcome by therapist (0.43), and M-BAT (0.57). GAS is moderately correlated with depression (0.32), and not significantly correlated with somatic anxiety. +/−
No hypotheses
Fisher 2002 No 149 Correlations with improvements in walking, general health questionnaire, Oswesty Low Back Pain Disability Questionnaire, NRS and change stand-sit and change PAIRS were measured. There was a significant correlation between GAS and improvements for walking (0.47), between GAS and the general health questionnaire (0.25) and between GAS and the OLBPDQ (−0.31), with p <0.01 for all three. No significant correlations were found between GAS and the NRS and change stand-sit and change PAIRS. +/−
No hypotheses
Gordon 1999 No 53 Correlations with standard scales of cognition (MMSE and Global Deterioration Scale), behavior (axis 8 of the brief cognitive rating scale), co-morbidity (cumulative illness rating scale), mobility and balance (hierarchical assessment of balance and mobility, HABAM), and functional capacity (Barthel Index); GAS did not correlate well with any of these measures (correlations varied from −0.22 to 0.17). +/−
No hypotheses
Khan 2008 No 24 Correlation with Barthel Index, Functional Independent Measure and Clinical Global Impression was measured; only the correlation with CGI was significant (−0.77). Also, the difference between responders and non-responders was measured, and a significant difference was found (Z = −3.78, p <0.001). +/−
No hypotheses
Palisano 1993 No 21 Correlations between GAS T-scores and Peabody Gross Motor Age equivalent change scores were measured; none of these correlations were significant. +/−
No hypotheses
Rockwood 1993 No 45 Correlations with change scores of Barthel Index, Functional Independent Measure, Mini-Mental State Examination, Katz ADL Index, Physical Self-Maintenance Scale, and Spitzer Quality of Life Index were measured. Correlations varied from −0.87 to 0.84, but it is unclear if these correlations are significant. +/−
No hypotheses, correlations between change scores
Rockwood 1996 Yes 15 A correlation with change scores is measured between GAS and Alzheimer’s Disease Assessment Scale-cognitive, Global Deterioration Scale, Clinical Global Impression, Mini-Mental State Examination, Physical Self Maintenance Scale, and the Instrumental Activities of Daily Living. Correlations varied from −0.85 to 0.74, but it is unclear if these correlations are significant. A T-test between the placebo and the intervention condition was also performed. The T-test showed no difference (p = 0.54). +/−
No hypotheses, correlations between change scores
Rockwood 1997 No 44 Correlations with two measurement instruments were measured: Clinical Global Impression (r = 0.73) for change score and (r = 0.63) at discharge. +/−
No hypotheses
Rockwood 2002 Yes 108 Correlations were measured between several goals within GAS and other measurement instruments. Mini-Mental State Examination and GAS cognition goals: r = 0.51. Alzheimer’s Disease Assessment Scale-cognitive and GAS cognition goals: r = −0.43. Physical Self Maintenance Scale and clinical function goals: r = −0.53. Patient-carer function goals and Physical Self Maintenance Scale: r = −0.47. Patient-carer function goals and Instrumental Activities of Daily Living: r = −0.44. +/−
No hypotheses
Sheldon 1998 No 82 GAS was correlated with the ‘rated attainment’ scale: r = 0.71 (p <0.001). There was a correlation with autonomy (r = 0.21, p <0.01), later effort (r = 0.42, p <0.01) and autonomous reasons (r = 0.09, p <0.05). +/−
No hypotheses
Steenbeek 2011 No 23 Correlation with Pediatric Evaluation of Disability Inventory Functional Status Score Mobility: r = 0.64 (p <0.01), correlation with PEDI Selfcare and social function was not significant. +/−
No hypotheses
Stolee 1999 No 173 Change and follow-up scores of GAS were correlated with Barthel Index, Older Americans Resource Scale Instrumental Activities of Daily Living, Mini-Mental State Examination, Global Rating, Nottingham Health Profile. The correlations varied from −0.31 to 0.67. +/−
No hypotheses
Turner-Stokes 2009 No 164 Correlations were measured between GAS and Functional Independent Measure and Functional Assessment Measure. Correlations with FIM + FAM scores were moderate: 0.36–0.43 for raw scores, 0.41–0.49 for GAS transformed FIM + FAM scores. +/−
No hypotheses
Turner-Stokes 2010 Yes 90 Correlations were measured between GAS and a composite spasticity score (MAS), Global Benefit patient report, Global Benefit investigator report, Hospital Anxiety and Depression Scale anxiety and Hospital Anxiety and Depression Scale depression, Pain at rest, Pain on movement, Assessment of Quality of Life, Patient Disability Score, and Carer burden score. Significant correlations between GAS and MAS (0.35), Global benefit patient report (0.46) and Global benefit investigator-report (0.41) were reported. Other correlations were not significant. +/−
No hypotheses
Turner-Stokes 2013 Yes 456 Correlations between GAS and ‘other measures of outcome, e.g. measures of spasticity, global benefit and other standardized measures’ were calculated. GAS correlated weakly with a reduction in total Modified Ashworth Scale at follow-up (Sp r = 0.28, p <0.0001) and with global assessment of benefit (r = 0.45, p <0.0001 for patient assessment, r = 0.38, p <0.0001 for investigator assessment). +/−
No hypotheses
Woodward 1978 No 279 GAS scores correlate significantly with other outcome measures: r = 0.12 - 0.39; p <0.05 (in the paper, it is not clear what these other outcome measures are). There was also a difference between the highest and lowest T-score differences: the highest scorers had a mean pre-post score difference of 42.70 (SD = 6.87), the lowest scorers had a mean pre-post difference of 4.05 (SD = 5.78). +/−
No hypotheses
Yip 1998 No 143 Correlations with the Standardized Mini-Mental State Examination, the modified Barthel Index, the Katz Index of ADL and the IADL subscale of the Older Americans Resources and Services Questionnaire were used to demonstrate the convergent construct validity of the standardized menu of GAS. Spearman correlations were calculated between GAS summary scores at discharge and change scores on the Barthel, Katz, OARS-IADL, and SMMSE. The correlations of the total GAS score with changes on the three measures of function were statistically significant but modest (r = 0.41 to 0.45); the correlation of GAS with the SMMSE change score was not significant (r = 0.11). +/−
Modest correlations