[Comparison of three methods for measuring multiple morbidity according to the use of health resources in primary healthcare].

OBJECTIVE

To compare three methods of measuring multiple morbidity according to the use of health resources (cost of care) in primary healthcare (PHC).

DESIGN

Retrospective study using computerized medical records.

SETTING

Thirteen PHC teams in Catalonia (Spain).

PARTICIPANTS

Assigned patients requiring care in 2008.

MAIN MEASUREMENTS

The socio-demographic variables were co-morbidity and costs. Methods of comparison were: a) Combined Comorbidity Index (CCI): an index itself was developed from the scores of acute and chronic episodes, b) Charlson Index (ChI), and c) Adjusted Clinical Groups case-mix: resource use bands (RUB). The cost model was constructed by differentiating between fixed (operational) and variable costs.

STATISTICAL ANALYSIS

3 multiple lineal regression models were developed to assess the explanatory power of each measurement of co-morbidity which were compared from the determination coefficient (R(2)), p< .05.

RESULTS

The study included 227,235 patients. The mean unit of cost was €654.2. The CCI explained an R(2)=50.4%, the ChI an R(2)=29.2% and BUR an R(2)=39.7% of the variability of the cost. The behaviour of the ICC is acceptable, albeit with low scores (1 to 3 points), showing inconclusive results.

CONCLUSIONS

The CCI may be a simple method of predicting PHC costs in routine clinical practice. If confirmed, these results will allow improvements in the comparison of the case-mix.