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The relationship between number of primary health care visits and hospitalisations: evidence from linked clinic and hospital data for remote Indigenous Australians.

Zhao Y, Wright J, Guthridge S, Lawton P - BMC Health Serv Res (2013)

Bottom Line: However, the evidence on whether improved PHC reduces hospitalisations has been mixed.For patients with diabetes, ischaemic heart disease or renal disease, the minimum level of hospitalisation was found when there was 20-30 PHC visits a year, and for children with otitis media and dental conditions, 5-8 visits a year.The authors propose that the effectiveness of a health system may hinge on a refined balance, rather than a straight-line relationship between primary health care and tertiary care.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Health, PO Box 40596, Casaurina, NT 0811, Australia. yuejen.zhao@nt.gov.au.

ABSTRACT

Background: Primary health care (PHC) is widely regarded as essential for preventing and treating ill health. However, the evidence on whether improved PHC reduces hospitalisations has been mixed. This study examines the relationship between PHC and hospital inpatient care in a population with high health need, high rates of hospitalisation and relatively poor PHC access.

Methods: The cross-sectional study used linked individual level PHC visit and hospitalisation data for 52 739 Indigenous residents from 54 remote communities in the Northern Territory of Australia between 1 July 2007 and 30 June 2011. The association between PHC visits and hospitalisations was modelled using simple and spline quadratic regression for key demographics and disease groups including potentially avoidable hospitalisations.

Results: At the aggregate level, the average annual number of PHC visits per person had a U-shaped association with hospitalisations. For all conditions combined, there was an inverse association between PHC visits and hospitalisations for people with less than four clinic visits per year, but a positive association for those visiting the clinic four times or more. For patients with diabetes, ischaemic heart disease or renal disease, the minimum level of hospitalisation was found when there was 20-30 PHC visits a year, and for children with otitis media and dental conditions, 5-8 visits a year.

Conclusions: The results of this study demonstrate a U-shape relationship between PHC visits and hospitalisations. Under the conditions of remote Indigenous Australians, there may be an optimal level of PHC at which hospitalisations are at a minimum. The authors propose that the effectiveness of a health system may hinge on a refined balance, rather than a straight-line relationship between primary health care and tertiary care.

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Average hospitalisations per person-year by average annual clinic visits for (a) demographic groups, (b) adult chronic diseases and (c) child health conditions for remote Indigenous patients, using simple quadratic models, Northern Territory, Australia, 2007–2011. Note: COPD = chronic obstructive pulmonary disease; IHD = ischaemic heart disease; PAH = potentially avoidable hospitalisation.
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Figure 3: Average hospitalisations per person-year by average annual clinic visits for (a) demographic groups, (b) adult chronic diseases and (c) child health conditions for remote Indigenous patients, using simple quadratic models, Northern Territory, Australia, 2007–2011. Note: COPD = chronic obstructive pulmonary disease; IHD = ischaemic heart disease; PAH = potentially avoidable hospitalisation.

Mentions: Figure 3 uses simple quadratic regression lines to compare the impacts of key demographics, chronic diseases and child health conditions on the PHC-hospital relationship. Inspecting panel a in Figure 3, we see that PAH (short green dashes) decreased from 0.7 to 0.2 hospitalisations per person-year when PHC visits increased from 0 to 15 visits annually. In other words, at least two-thirds of PAHs may potentially be avoided by providing adequate levels of PHC. By comparing with the total hospitalisations (solid black curve), this difference was equivalent to a reduction of PAHs from 59% to 28% of the total hospitalisations. In contrast, the curve for non-PAH was rather flat (pink dashes in panel a), and generally increased with PHC visits. Panel a in Figure 3 also compares the PHC-hospital relations by key demographics. The PHC visits associated with the minimum level hospitalisation was slightly greater in females (5–16 visits per person-year) and much greater in people aged 40 years and over (9–24) (Table 3 and panel a, Figure 3). Patients with renal disease, diabetes, hypertension and IHD showed a clearer effect of U-curve than COPD (panel b, Figure 3). The U-curve effects were more pronounced for children with gastroenteritis, respiratory infection and RHD than the other three conditions (panel c). It is also noteworthy that children with 5–8 clinic visits a year for otitis media and dental conditions, and 6–20 visits a year for RHD had the minimum level of hospitalisations (Table 3). For clarity, spline quadratic models and 95% confidence intervals for demographics, chronic diseases and child health conditions were omitted from Figure 3. Sensitivity analysis reveals that including truncated outliers of excessive clinic visits (200+) did not significantly alter the results but reduced overall fit. Further analysis revealed that these truncated patients were more likely to have one or more chronic conditions (50.1% diabetes, 20.5% IHD, 23.0% renal disease, compared with 5.1%, 3.0% and 3.3% in the total respectively), and more likely to be older (23.6% aged 60 and over vs 5.3%) and female (64.5% vs 52.4%). Removal of same day haemodialysis from the analysis resulted in reduction of the hospitalisations due to renal disease, but the U-curve effect remained (data not shown).


The relationship between number of primary health care visits and hospitalisations: evidence from linked clinic and hospital data for remote Indigenous Australians.

Zhao Y, Wright J, Guthridge S, Lawton P - BMC Health Serv Res (2013)

Average hospitalisations per person-year by average annual clinic visits for (a) demographic groups, (b) adult chronic diseases and (c) child health conditions for remote Indigenous patients, using simple quadratic models, Northern Territory, Australia, 2007–2011. Note: COPD = chronic obstructive pulmonary disease; IHD = ischaemic heart disease; PAH = potentially avoidable hospitalisation.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4226196&req=5

Figure 3: Average hospitalisations per person-year by average annual clinic visits for (a) demographic groups, (b) adult chronic diseases and (c) child health conditions for remote Indigenous patients, using simple quadratic models, Northern Territory, Australia, 2007–2011. Note: COPD = chronic obstructive pulmonary disease; IHD = ischaemic heart disease; PAH = potentially avoidable hospitalisation.
Mentions: Figure 3 uses simple quadratic regression lines to compare the impacts of key demographics, chronic diseases and child health conditions on the PHC-hospital relationship. Inspecting panel a in Figure 3, we see that PAH (short green dashes) decreased from 0.7 to 0.2 hospitalisations per person-year when PHC visits increased from 0 to 15 visits annually. In other words, at least two-thirds of PAHs may potentially be avoided by providing adequate levels of PHC. By comparing with the total hospitalisations (solid black curve), this difference was equivalent to a reduction of PAHs from 59% to 28% of the total hospitalisations. In contrast, the curve for non-PAH was rather flat (pink dashes in panel a), and generally increased with PHC visits. Panel a in Figure 3 also compares the PHC-hospital relations by key demographics. The PHC visits associated with the minimum level hospitalisation was slightly greater in females (5–16 visits per person-year) and much greater in people aged 40 years and over (9–24) (Table 3 and panel a, Figure 3). Patients with renal disease, diabetes, hypertension and IHD showed a clearer effect of U-curve than COPD (panel b, Figure 3). The U-curve effects were more pronounced for children with gastroenteritis, respiratory infection and RHD than the other three conditions (panel c). It is also noteworthy that children with 5–8 clinic visits a year for otitis media and dental conditions, and 6–20 visits a year for RHD had the minimum level of hospitalisations (Table 3). For clarity, spline quadratic models and 95% confidence intervals for demographics, chronic diseases and child health conditions were omitted from Figure 3. Sensitivity analysis reveals that including truncated outliers of excessive clinic visits (200+) did not significantly alter the results but reduced overall fit. Further analysis revealed that these truncated patients were more likely to have one or more chronic conditions (50.1% diabetes, 20.5% IHD, 23.0% renal disease, compared with 5.1%, 3.0% and 3.3% in the total respectively), and more likely to be older (23.6% aged 60 and over vs 5.3%) and female (64.5% vs 52.4%). Removal of same day haemodialysis from the analysis resulted in reduction of the hospitalisations due to renal disease, but the U-curve effect remained (data not shown).

Bottom Line: However, the evidence on whether improved PHC reduces hospitalisations has been mixed.For patients with diabetes, ischaemic heart disease or renal disease, the minimum level of hospitalisation was found when there was 20-30 PHC visits a year, and for children with otitis media and dental conditions, 5-8 visits a year.The authors propose that the effectiveness of a health system may hinge on a refined balance, rather than a straight-line relationship between primary health care and tertiary care.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Health, PO Box 40596, Casaurina, NT 0811, Australia. yuejen.zhao@nt.gov.au.

ABSTRACT

Background: Primary health care (PHC) is widely regarded as essential for preventing and treating ill health. However, the evidence on whether improved PHC reduces hospitalisations has been mixed. This study examines the relationship between PHC and hospital inpatient care in a population with high health need, high rates of hospitalisation and relatively poor PHC access.

Methods: The cross-sectional study used linked individual level PHC visit and hospitalisation data for 52 739 Indigenous residents from 54 remote communities in the Northern Territory of Australia between 1 July 2007 and 30 June 2011. The association between PHC visits and hospitalisations was modelled using simple and spline quadratic regression for key demographics and disease groups including potentially avoidable hospitalisations.

Results: At the aggregate level, the average annual number of PHC visits per person had a U-shaped association with hospitalisations. For all conditions combined, there was an inverse association between PHC visits and hospitalisations for people with less than four clinic visits per year, but a positive association for those visiting the clinic four times or more. For patients with diabetes, ischaemic heart disease or renal disease, the minimum level of hospitalisation was found when there was 20-30 PHC visits a year, and for children with otitis media and dental conditions, 5-8 visits a year.

Conclusions: The results of this study demonstrate a U-shape relationship between PHC visits and hospitalisations. Under the conditions of remote Indigenous Australians, there may be an optimal level of PHC at which hospitalisations are at a minimum. The authors propose that the effectiveness of a health system may hinge on a refined balance, rather than a straight-line relationship between primary health care and tertiary care.

Show MeSH
Related in: MedlinePlus