Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2020 Apr 26;20(1):359.
doi: 10.1186/s12913-020-05205-6.

Number of consulting medical institutions and risk of polypharmacy in community-dwelling older people under a healthcare system with free access: a cross-sectional study in Japan

Toshiki Suzuki  1   2 , Masao Iwagami  3   4 , Shota Hamada  5   6 , Tomoyuki Matsuda  2   5   7 , Nanako Tamiya  2   5
Affiliations

Number of consulting medical institutions and risk of polypharmacy in community-dwelling older people under a healthcare system with free access: a cross-sectional study in Japan

Toshiki Suzuki et al. BMC Health Serv Res. .

Abstract

Background: Under the Japanese free access healthcare system, patients are allowed to consult multiple medical institutions (including clinics and hospitals for general or specialist consultation) without primary care referral. This potentially increases the risk of polypharmacy. We examined the association between the number of consulting medical institutions and polypharmacy under a healthcare system with free access.

Methods: Via a self-administered questionnaire, we identified people aged ≥65 years with ≥1 disease and ≥1 consulting medical institution in a Japanese city in 2016. The exposure of interest was the number of consulting medical institutions (1, 2, or ≥3) and the outcome was polypharmacy (use of ≥6 types of drugs). We performed a multivariate logistic regression analysis, adjusting for age, sex, household economy, and the number and type of comorbidities. To minimize confounding effects, we also performed propensity-score-matched analysis, categorizing patients into two groups: 1 and ≥2 consulting medical institutions.

Results: Of 993 eligible individuals (mean (standard deviation) age: 75.1 (6.5) years, men: 52.6%), 15.7% (156/993) showed polypharmacy. Proportions of polypharmacy were 9.7% (50/516), 16.6% (55/332), and 35.2% (51/145) for people who consulted 1, 2, and ≥3 medical institutions, respectively. Relative to people who consulted 1 medical institution, adjusted odds ratios (95% confidence intervals) for polypharmacy were 1.50 (0.94-2.37) and 3.34 (1.98-5.65) for those who consulted 2 and ≥3 medical institutions, respectively. In propensity score matching, of 516 and 477 patients who consulted 1 and ≥2 medical institutions, 307 pairs were generated. The proportion of polypharmacy was 10.8% (33/307) and 17.3% (53/307), respectively (P = 0.020). The odds ratio for polypharmacy (≥2 vs. 1 consulting medical institution) was 1.73 (95% confidence interval 1.09-2.76).

Conclusions: Patients who consulted more medical institutions were more likely to show polypharmacy. The results could encourage physicians and pharmacists to collect medication information more actively and conduct appropriate medication reviews. Strengthening primary care is needed to address the polypharmacy issue, especially in countries with healthcare systems with free access.

Keywords: Free access; Multiple consultations; Number of consulting medical institutions; Polypharmacy.

PubMed Disclaimer

Conflict of interest statement

Nanako Tamiya is Editorial Board Member.

Figures

Fig. 1
Fig. 1
Number of prescribed drugs according to number of consulting medical institutions
Fig. 2
Fig. 2
Outline of patient selection in the propensity-score-matched analysis
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

References

    1. Abe T, Tamiya N, Kitahara T, Tokuda Y. Polypharmacy as a risk factor for hospital admission among ambulance-transported old-old patients. Acute Med Surg. 2016;3(2):107–113. doi: 10.1002/ams2.153. - DOI - PMC - PubMed
    1. Field TS, Gurwitz JH, Avorn J, et al. Risk factors for adverse drug events among nursing home residents. Arch Intern Med. 2001;161(13):1629–1634. doi: 10.1001/archinte.161.13.1629. - DOI - PubMed
    1. Suzuki Y, Sakakibara M, Shiraishi N, Hirose T, Akishita M, Kuzuya M. Prescription of potentially inappropriate medications to older adults. A nationwide survey at dispensing pharmacies in Japan. Arch Gerontol Geriatr. 2018;77:8–12. doi: 10.1016/j.archger.2017.12.010. - DOI - PubMed
    1. Onder G, Liperoti R, Foebel A, et al. Polypharmacy and mortality among nursing home residents with advanced cognitive impairment: Results from the Shelter Study. J Am Med Dir Assoc. 2013;14(6):450. doi: 10.1016/j.jamda.2013.03.014. - DOI - PubMed
    1. Fushiki Y, Kinoshita K, Tokuda Y. Polypharmacy and adverse drug events leading to acute care hospitalization in Japanese elderly. Gen Med. 2014;15(2):110–116. doi: 10.14442/general.15.110. - DOI