Table 4.

Range of negative PMI, standard deviation, median and mean weighted by sample size for selected subgroups and for the whole study pool

Characteristics of studies	No. of studies	Range of negative PMI (%)	Standard deviation	Median	Weighted mean
Year
1994–2000	12	27–79	18.47	46.5	46.6
2001–2007	14	8–82	26.33	60.0	41.5
Geographic area
United States	8	8–65	19.14	33.0	39.1
Europe	8	9–82	26.62	51.0	40.3
Asia	9	27–79	17.47	69.0	59.1
Economic level
GNI per capita < $20 000	8	31–79	17.37	68.0	53.7
GNI per capita $20 000–$40 000	7	13–82	25.75	51.0	48.2
GNI per capita ≥$40 000	11	8–65	20.72	37.0	34.2
Settinga
Specific for cancer patients or hospiceb	15	8–79	21.33	53.5	52.2
Not specificb	5	29–74	23.45	46.5	42.8
Mixed	5	9–82	27.00	58.0	44.6
Stage of diseasea
At least 68.8% metastatic	8	13–65	16.54	39.5	31.2
<68.8% metastatic	12	29–82	17.75	66.0	58.4
Mean age of the samplea
≥58 years old	11	27–79	19.62	65.0	55.1
<57 years old	11	8–82	21.52	43.0	53.6
Total	26	8–82	22.63	51	43.40

^aIn some of the studies included in the review this characteristic was not specified.

^bPMI score extracted from Russel et al. has been splitted.

PMI, Pain Management Index.