Article category
Original article

Title
Diagnostic difficulties and factors affecting diagnosis in acutely ill elderly Japanese patientsliving at home

Conflicts of interest
The authors have no conflicts of interest directly relevant to the content of this article.

Running title
Diagnosis of acutely ill elderly patients at home1

Authors and Affiliations
Tsunetaka Kijima1), Kenju Akai2), Toru Nabika3), Eisaku Taniguchi4), Akira Matsushita5),
Yutaka Ishibashi1)1) Department of General Medicine, Faculty of Medicine, Shimane University
2) Center for Community-based Healthcare Research and Education, Shimane University3) Department of Functional Pathology, Faculty of Medicine, Shimane University4) Department of community medicine management, Faculty of Medicine, Shimane
University5) Nagi family clinic, Tsuyama family clinic, Yunogou family clinic, Family Practice Centerof Okayama

2

Abstract
Background: Home visits by primary care physicians to elderly patients in Japan haveincreased as part of a government initiative to relieve pressure on acute care hospitals.
However, there is evidence of discrepancies between diagnoses in the primary care andhospital settings.
Methods: We conducted a retrospective cross-sectional study using two years of medical
records from a primary care center to investigate diagnostic accuracy of acutely ill elderly
patients in the primary care setting, and reasons for emergency hospital admissions. We
analyzed data from all cases where extra home visits were needed due to acute illness, andused inferential statistics to compare initial diagnosis with final diagnosis and analyze thefactors affecting diagnostic accuracy.
Results: We analyzed 591 cases (mean age of patients: 85 years). The most common reasonsfor emergency hospitalization were respiratory, gastrointestinal, or cardiovascular diseases.
There was a significant difference in initial diagnostic accuracy between respiratory diseases,
gastrointestinal diseases, and other conditions (p=0.005); an accurate diagnosis was likely for
respiratory diseases but unlikely for gastrointestinal diseases. Polypharmacy (≥8 medications)
was associated with low diagnostic accuracy on multivariable logistic regression analysis(odds ratio, 0.24; 95% confidence interval, 0.06-0.67; p=0.006).
Conclusion: Primary care providers should note subtle symptoms and the number of3

medications taken, provide follow-up, and consider gastrointestinal diseases when making adiagnosis following acute changes in an elderly patient.

Keywords
Acute illness, diagnosis, elderly, polypharmacy, primary care4

1. Introduction
The dramatic increase of the aged population is a pressing problem in Japan; the number ofpeople aged 75 or over is expected to reach 22 million by 2025, accounting for 25% of the
population.1 The Japanese government has promoted various long-term-care services,
including home visits rather than inpatient admissions, to cope with this growing pressure on
medical resources.2 In the Japanese health insurance system, physicians visit elderly patientsin their own homes or residential care twice monthly. If patients have more significant needs,
urgent consultations or emergency hospital admissions can be arranged.1 As morbidity andmortality from infections, adverse effects of drugs, and other complications are greater in theelderly,3, 4 physicians must often make prompt diagnoses when visiting elderly patients tomanage their conditions appropriately.3 However, deciding whether to admit patients can bedifficult due to the limited diagnostic tools available during a home visit.5 Functional
disability, polypharmacy, lowered immunity, and other physiological decline5 leading tocomorbidities6-8 may amplify the difficulty. However, as hospitalization is also a known risk
factor for functional decline4, 5 and other health problems in the elderly,9-11 unnecessary
hospitalization should be avoided.
Pretest probability is important in clinical decision making.12 Irrespective of the medical
setting, information on incidence and prevalence of a disease and consideration of the risk
factors are essential to improve diagnostic accuracy.13 We conducted a retrospective survey
5using the medical records of elderly patients hospitalized as emergencies, and considered theclinical significance of our findings.

6

2. Materials and Methods
The study was performed in a clinic providing primary-care home visits in a rural area of
Okayama, Japan. The clinic was an outpatient family-medicine training center with three tosix doctors, including family medicine residents. We reviewed medical records of patients
receiving routine medical care in their own homes or care homes who were admitted tohospital as emergencies due to acute illness between January 1, 2011 and December 31, 2012.
We defined emergency hospitalization as admission to the hospital within four days after
additional home visits by primary-care physicians.
We collected and analyzed data on age, sex, number of medications taken, physician’s
clinical experience, number of days between home visit and hospitalization, proportion ofpatients who returned home three months after admission to the hospital, whether patients
lived alone or with family members, place of residence (own home or care home), activities ofdaily living (ADL), level of care needed according to the Japanese long-term-care insurance
system,1, 14 Charlson Comorbidity Index (CCI),15 updated CCI,16 catheterization (gastrostomy
and/or urinary catheter), nutritional status (last serum albumin level in the six months prior tohospitalization), initial diagnosis, final diagnosis, history of pneumonia, hospitalization within
the previous year, history of gastrointestinal disease (peptic ulcer disease, biliary calculus, or
hepatitis), and history of cardiovascular disease (cerebrovascular disease, congestive heart
failure, myocardial infarction, or peripheral vascular disease). The level of care-need was7classified as levels 1-5, from no care required to constant support needed, based on expert
evaluations of the patient’s mental and physical status. According to previous studies17, 18, we
further categorized the care-need levels into three groups: low-level (less than care level),
middle-level (care-need level 1-2), high-level (care-need level 3-5). Need for greater support
corresponded with a higher care-need level, lower ADL index, and lower cognitive function.
In all patients, the initial diagnosis was defined as the diagnosis recorded in the medical
records following a home visit, after taking a medical history and performing a physicalexamination, simple blood tests (complete blood count [CBC], C-reactive protein [CRP] andblood glucose levels), urine analysis, and electrocardiogram. The final diagnosis was definedas the diagnosis made in secondary or tertiary medical facilities. Diagnoses were classified
according to the International Classification of Diseases, 10th Revision (ICD-10); the initialdiagnosis was considered accurate when the initial and final diagnoses were the same, or
when the same differential diagnoses were included in both initial and final diagnoses.
Diagnostic accuracy in this study was assessed by three physicians, each of whom had morethan 10 years of clinical experience, including a fellow from the Japanese Society of Internal
Medicine and a certified diplomate from the American Board of Family Medicine.
Student’s t-test, the Wilcoxon rank-sum test, the chi-square test, and the Cochran-Armitage
test for trend were used to analyze parametric, non-parametric, categorical, and discretevariables, respectively. The level of significance (p) was <0.05 for all tests. Statistical analysis
8was carried out using JMP® Pro12 software (SAS Institute Inc., Cary, NC, USA).
The study was advertised on the Shimane University and primary care websites. All
participants were presumed to consent unless they contacted the study group to opt out. As thestudy was retrospective, the requirement for written informed consent was waived by the
Shimane University Institutional Committee on Ethics, which approved the study design.

93. Results
No patient opted out of the study. We found that 125.5 patients per month lived at home orin care homes and had difficulty visiting medical surgeries. A total of 591 encounters (25encounters/month) were extra domiciliary visits. A total of eight primary-care physicians took
part in the study. In total, 81 encounters (68 patients, 3.4 cases/month) resulted in patients’admission to the hospital within four days of the initial home visit. Patients ranged from 57 to
101 years old (mean age: 85±8.5 years). The interval between the physician's visit andhospital admission was recorded as “same day” (n=35), “next day” (n=24), “two days later”(n=3), “three days later” (n=18), or “four days later” (n=1). Cases where the final diagnosis
was not known (n=4) were excluded, leaving 77 of 81 cases eligible for this study. This
number included multiple admissions of the same patient. As there was no significant
difference in diagnostic accuracy on first admission and subsequent admissions for patientswith multiple admissions (60% versus 54%; p=1.00), all emergency admissions wereanalyzed as independent events. Thirty percent (23/77) of the patients returned home threemonths after emergency hospitalization.
Primary reasons for emergency admission were pneumonia (n=28) followed by calculus ofbile duct with cholangitis (n=5), and acute appendicitis (n=3) (Table 1). Initial diagnostic
accuracy was 80% (24/30) for respiratory and 33.3% (6/18) for gastrointestinal diseases. Poor
diagnostic accuracy of the latter was significantly higher in the older age group (p=0.03).
10

There was a slight but non-significant association between low ADL index and poor
diagnostic accuracy (p=0.14). No association was observed with other variables, such as sex,dementia, history of gastrointestinal disease, history of cardiovascular disease, nutritional
state, or indwelling catheter.
Table 2 shows the characteristics relating to initial diagnostic accuracy. The number of
medications taken was associated with significantly low initial diagnostic accuracy (p=0.013
for trend); the median value was nine in the incorrect and six in the correct diagnosis groups.
Significantly low initial diagnostic accuracy was found with patients taking eight or more
medications (43% diagnostic accuracy with ≥8 medications, versus 74% in <8 medications;
p=0.006). We did not observe any association between the number of medications (≥8
medications) and updated CCI score, but there was a significant positive association withhistory of cardiovascular disease (p<0.001). There was a significant difference in diagnostic
accuracy between respiratory and gastrointestinal diseases, and other diagnoses. On home
visits, respiratory diseases were more likely to be diagnosed than were gastrointestinal
diseases. The number of medications included long-term medications, and excluded
non-prescription analgesic drugs and eye drops, as the actual dosage for these was unknown.
Table 3 shows the factors associated with initial diagnostic accuracy on multivariablelogistic regression analysis. We found a significant association between patients taking eightor more medications and low initial diagnostic accuracy. This result remains even when we
11included history of pneumonia and admissions over the last year, diabetes mellitus,
malignancies, dementia, living alone, living in a residential care home, and history ofgastrointestinal and cardiovascular diseases.

12

4. Discussion
When selecting variables, we focused on CCI, ADL, dementia, number of medications taken(≥8 medications), and the physician’s clinical experience. The CCI is an index ofcomorbidities used to estimate one-year mortality.15 We used the updated CCI, which wasdeveloped according to new medical advances.16 Following previous studies, we categorizedcases into four groups: 0, 1, 2, ≥3.16, 19 A higher risk of fever has been noted in people with a
low ADL index, such as wheelchair users or those who are bedridden, than in the ambulatory
population.20 Poor cognition may increase communication difficulties and obscure signs ofinfection.5 Polypharmacy is reported to be associated with a decline in cognitive capacity orfunctional ability, using three groups: non-polypharmacy (0-5 medications), polypharmacy(6-9 medications) and excessive polypharmacy (≥10 medications).21, 22 We followed thiscategorization in our study. An association has also been found between clinical performanceof physicians and their length of time in practice or age.23
Respiratory diseases, skin and soft tissue infections, and urinary tract infections have beenreported as the leading causes of fever in elderly patients living at home.3,20 We did not limit
our study to new cases of fever, and found that most emergency admissions due to fever were
for respiratory diseases (39%) followed by gastrointestinal diseases (26%). This discrepancy
may be because skin, soft tissue, and urinary tract infections could be treated in an outpatientsetting by oral or intravenous antibiotics, whereas gastrointestinal diseases such as
13cholecystitis, cholelithiasis, or appendicitis require inpatient treatment. Another study24 notedbiliary tract disease as the most common reason for intra-abdominal surgery in the elderly,with the incidence of cholelithiasis more than 50% in patients over 70 years old. This may
have accounted for differences in frequency of diagnoses.
In our study, gastrointestinal diseases had the lowest diagnostic accuracy. Crombie,25
Hampton26 and Sandler27 reported that taking a history and conducting a physical examination
contributed to 73-91% of the final diagnosis; another study28 reported that simple
investigations such as blood or urine tests, electrocardiograms, and radiography contributed to
81% of the final diagnosis. Our study indicated these factors had a 62% diagnostic value. The
likely reason for this difference is the influence of factors such as the older age of patients andtheir backgrounds, difficulty in assessing patients’ symptoms outside the surgery, doctors’level of experience, high mismatch rate in the emergency department,29 and a wider range of
diseases in our study. Diagnostic accuracy of abdominal conditions is reported to be lower inthe elderly,22 and as high as 40% of elderly patients with acute abdominal conditions havebeen reported as misdiagnosed.22, 28 Poor diagnostic accuracy of gastrointestinal diseases inthis study was highly associated with older age, and there was an association, albeit
non-significant, with low ADL index.
Diagnostic errors have been categorized as no-fault errors (masked or unusual presentationof disease or patient-related errors); system-related errors (technical failure, equipment
14

problems, and organizational flaws); and cognitive errors (faulty knowledge, data gathering,and faulty synthesis).30 In our study, one patient with appendicitis presented with only
low-grade fever, a reported slight alteration in behavior, no abdominal pain or change inappetite, and normal gait. This shows that examination of elderly patients can result ininevitable no-fault errors because of masked or unusual presentation of symptoms,
particularly within a primary-care setting. Acute appendicitis is reported to have an atypicalpresentation in the elderly31 and is initially misdiagnosed in 40-50% of the elderly
patients.24,31
Our study also revealed that it became more difficult to reach an early, accurate diagnosis inelderly patients who were taking eight or more medications, even though they were more
severely ill. There was a significant association between taking eight or more medications andhistory of cardiovascular disease, since these patients tend to take more medications, which
are usually difficult to reduce because of their importance in disease control. Although historyof cardiovascular diseases was not directly related to poor diagnostic accuracy in our study,
these patients take more medications, which may mask other conditions. “Taking eight ormore medications” had a greater impact on accurate diagnosis than any other comorbidity inthe patient’s medical history. A study of polypharmacy noted that taking five or more
medications decreased the diagnostic accuracy of tests for identifying frailty in older people.32
Our study has several limitations. First, it was a retrospective study using medical records.
15

Secondly, the quality of the medical records depended on each physician, and there is apossibility that physicians did not record information that they considered irrelevant. Thirdly,
data for alternative medicines or over-the-counter drugs were not appropriately documented
and were likely underestimated. Finally, this study was conducted on a relatively small
number of patients at one medical facility. As the initial diagnoses in this study were made by
only eight doctors at a single clinic, albeit representative of similar primary care clinics inJapan, caution should be exercised in extrapolating our results. Furthermore, although thenumber of medications was analyzed, their type was not evaluated.
In conclusion, it can be extremely challenging for primary care physicians to diagnose acuteearly-stage illnesses in the elderly, particularly during home visits. Respiratory diseases,
followed by gastrointestinal diseases, were the main reasons for emergency hospital
admissions in the elderly patients living at home and unable to visit medical facilities. Low
initial diagnostic accuracy was associated with taking eight or more medications, possibly
because signs of the disease were either masked or unusual. The number of medications waslargely dependent on past history of cardiovascular diseases. We recommend that primary care
physicians pay close attention to subtle symptoms and offer prudent follow-up, consider the
possibility of gastrointestinal diseases, and take into account polypharmacy and history of
cardiovascular disease when forming a diagnosis involving an acute change in an elderly
patient.
16

Funding/support statement
The Department of General Medicine, Faculty of Medicine Shimane University is anendowment department, supported by Ohda City.

17

Acknowledgments
The authors would like to thank Professor Kristina Sundquist and Professor Jan Sundquist
from the Center for Primary Health Care Research, Department of Clinical Sciences, Lund
University for help in interpreting the results of this study.

18

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23

Table 1 Main reasons for emergency admission, classified according to ICD-10 (n=77)
Main reasons for emergency admission
Type of diseasen
CodeFinal diagnosis

Endocrine, metabolic
E87.5

Hyperkalemia

1

F05.1

Delirium superimposed on dementia

1

disorderPsychiatric and nervous

Other psychoactive substance-related
F19

diseases1
disorders

G06.0

Intracranial abscess

1

I50

Heart failure

3

I21

Acute myocardial infarction

1

I63

Cerebral infarction

1

I61.9

Nontraumatic intracerebral hemorrhage

1

I26.9

Pulmonary embolism

1

I73

Peripheral vascular disease

1

J18

Pneumonia

28

Cardiovascular system

Respiratory system

Chronic obstructive pulmonary disease
J44.02
with acute lower respiratory infection
24K80.3Calculus of bile duct with cholangitis

5

K85.1

Biliary acute pancreatitis

2

K81.0

Acute cholecystitis

2

K35

Acute appendicitis

3

K40

Inguinal hernia

1

K44

Diaphragmatic hernia

1

K26.0

Duodenal ulcer

1

K65.0

Acute peritonitis

1

K52

Noninfective gastroenteritis and colitis

1

A09

Infectious gastroenteritis and colitis

1

B02.8

Herpes zoster with other complications

1

L89

Decubitus ulcer and pressure area

1

L88

Pyoderma gangrenosum1

M11.2 Chondrocalcinosis, elbow

1

N71

Inflammatory disease of uterus

1

N10

Acute pyelonephritis

1

S32.0

Fracture of unspecified lumbar vertebra

1

S22.0

Fracture of thoracic vertebra

1

S70.9

Unspecified superficial injury of hip and

1

Gastrointestinal system

Skin

Musculoskeletal system

Urogenital system

Damage25

thighFracture of unspecified part of neck of
S72.0

2
femur

Others

T02.1

Fracture of lumbar and thoracic vertebra

1

C22.0

Liver cell carcinoma (rupture)

1

C18

Malignant neoplasm of colon

1

R56.8

Unspecified convulsions

1

R50.9

Fever, unspecified

1

Z43.1

Attention to gastrostomy

1

Total

77

ICD-10 = International Classification of Diseases 10th Revision, 201426

Table 2 Characteristics of incorrect and correct diagnoses at initial medical examination(n=77)
Initial diagnostic accuracy
Incorrect

Correct

diagnosis

diagnosis

ni=29

nc=48

Mean ± SD

Mean ± SD

P-valueaAge

85.6 ± 7.1

84.3 ± 7.1

0.48

Physician’s clinical experience (years)

9.8 ± 6.6

7.6 ± 4.9

0.17Albumin (g/dL) (ni=23 vs. nc=42)

3.44 ± 0.5

3.39 ± 0.5

0.46

n

n

P-valueb

18

21

0.11

Respiratory system

6240.005*

Gastrointestinal system

126

Others11

18

Diabetes mellitus

7

4

0.05

Malignancy

5

7

0.75

VariableSex (female)
Final diagnosis:

27

Dementia

13

29

0.18

History of pneumonia in the last year

7

14

0.63

History of admission over the last year

19

24

0.18

History of digestive disease

6

10

0.98

History of circulatory disease

21

24

0.06

Non-polypharmacy

7200.013*Polypharmacy

10

21

Excessive polypharmacy

12

7

8

15

0.29

Patients living alone

6

7

0.48

Patients living in residential care

3

7

0.69

ADL (wheelchair users or bedridden)

10

22

0.32

Low-level

5

3

0.28

Middle-level

815High-level

15

27

Gastrostomy

55

Number of medications:

Returning home ratio at 3 months after
admission to hospital

Level of care need (ni=28 vs. nc=45):

28

0.39

Urinary catheter

4

6

0.87

0

3

2

0.73

1

0

2

2

6

18

3 or more

20

26

Updated CCI:aWilcoxon rank-sum testb

Differences between groups were assessed using the Chi-square test. Number of

medications, level of care-need, and updated CCI were analyzed using the
Cochran-Armitage test for trend in proportioni

incorrect diagnosis; c correct diagnosis

ADL = activities of daily living; SD = standard deviation; CCI = Charlson comorbidityindex* P <0.05

29

Table 3 Factors associated with initial diagnostic accuracy on multivariable logistic
regression analysis (n=77)
Model 1
Variable

OR (95% CI)

Model 2
P-value0.98
aAge (per 1 year)OR (95% CI)
0.98

0.71

0.61

(0.90-1.08)(0.89-1.07)

0.48

0.36

Sex (female)

0.18

Number of medications

0.09(0.15-1.43)(0.09-1.18)

0.24

0.22
0.006*(≥8 drugs)
Physician’s clinical0.003*(0.06-0.67)(0.07-0.61)

0.93

0.92
0.09

experience (years)

a

0.06

(0.84-1.02)(0.83-1.01)

0.94

0.94

Updated CCI

P-value

0.66(0.71-1.26)

0.63(0.71-1.25)

ADL (wheelchair users
1.1 (0.36-3.33)

0.85

or bedridden)
Catheterization

0.34
0.16

(gastrostomy and/or(0.06-1.59)
30

urinary catheter)a

Per 1-year increase

ADL = activities of daily living; CI = confidence interval; OR = odds ratio; CCI =Charlson comorbidity index* P <0.0131