This study found that the patients in the intervention group had a lower risk for first hospital admission within 12 months after the MR compared to the patients in the control group. We found no difference in mortality rate between the groups. The study design with per protocol analysis instead of intention to treat analysis might have contributed to biased survival estimates, as patients in the control group receiving MR during the follow up time were excluded from the analysis. However, MRs in the control group were performed both as a part of the routine care and due to concerns about medication use that may have been related to condition deterioration. We believe therefore that the risk for bias is lower than expected.
The studied population was elderly individuals that had multimorbidity and polypharmacy. The intervention and the control group were similar concerning age, living form and number of drugs at baseline.
Adverse drug reactions account for a substantial amount of all hospital admissions (17-19), and many of these are preventable (18, 19). Previously published data from this RCT (12) showed no difference in number of drugs or PIMs between the groups at baseline but a significantly lower number of drugs and PIMs in the intervention group at two months follow-up, which indicates that MRs might reduce the occurrence of drug-related problems (DRPs). If DRPs can be prevented by reducing the number of drugs and PIMs through MRs, some hospital admissions could be avoided or delayed, and thereby could save both burden and costs for the individual patient as well as for the society.
Many studies of MRs are based on a patient population already admitted to the hospital and have shown that MRs in a hospital setting will extend the time to readmission (20-22). A strength of this study was that the MRs were performed in primary care, therefore adding this perspective to the body of evidence. We estimate the effect of the MR on direct patient outcomes such as hospital admissions, which is reliable data thanks to Swedish personal numbers.
Another strength of this study is the long follow-up time (12 months), which is rare in this kind of study (9), due to the high mortality rate among this frail group of elderly patients. The two most common intervention recommendations the pharmacist presented to the physician were withdrawal of drug therapy and reduced dosage. Many PIMs, as long-acting benzodiazepines and tramadol need a longer withdrawal period with an initial stepwise lowered dosage. The long follow-up period in the present study allowed a clinical effect of the medication withdrawal; this is a strength of this study. However, a major limitation is that additional data about medications was not collected after the initial follow up at two months from base line, to confirm the assumption of maintained or increased withdrawal of PIMs.
Censoring the individuals in the control group, which had received a MR, when the survival analysis was performed is also a strength of the study.
A major limitation of the study is the lack of information about patients’ base line comorbidities, the reason for hospital admissions or if the hospital admission was due to a DRP. Some of the hospital admissions could be assumed to be related to DRPs as the previous paper on the same population showed a high incidence of reported falls (29%) and severe falls leading to hospital admissions (17%) prior to baseline (12). Thus, further analysis on the possible association between DRPs and hospital admissions needs to be performed.
We have not analyzed data on morbidity such as number of chronic conditions and/or cognitive impairment, and this is a limitation of the study. Given the similarities in the number of drugs both between groups and between patients in different living forms, we can only assume that there were similar levels of multimorbidity in the groups.
We found a positive effect of MRs on the risk for hospital admissions. As it is not solely about avoiding hospital admission, the impact of MRs on quality of life would be interesting to assess as only a few studies have raised this important question (7, 23).
Our results showed that MRs had no effect on mortality or on time to death when the intervention group and control group were compared, which is in-line with other research (4, 24).
It has been argued that MRs are part of the physicians' professional responsibilities. However, the multi-professional approach with pharmacist and nurse involvement might bring different dimensions upon patients’ medication list, giving additional attention to frail elderly in an over-burdened primary care.
About 90,000 individuals over the age of 65 live in nursing homes in Sweden. This number represents less than 5% of the population aged 65 years and older (25) and hence is the part of the elderly population needing most daily care. We suggest that frail elderly individuals should be treated with increased attention, including by conducting MRs, in order to avoid hospital admissions.