Validation of an administrative claims-based diagnostic code for pneumonia in a US-based commercially insured COPD population

Figures & data

Figure 1 Patient selection.

Notes: *Could not locate provider (n=36), no record of patient (n=44), no record of patient in timeframe requested (n=32), provider refuses to participate (n=52), provider requires patient consent or IRB approval (n=41), chart lost/destroyed/archived (n=11), no response from office (n=63), payment denied/record not needed (n=3), requests suspended (met quota) (n=41).
Abbreviations: DOB, date of birth; IRB, institutional review board.

Table 1 Patient demographics

	All pneumonia patients identified in claims (N=1,345)		Medical record status
			All medical records (N=388)		Documented pneumonia diagnosis (N=311)		No documented pneumonia diagnosis (N=77)
Female (n, %)	711	52.9%	209	53.9%	160	51.4%	49	63.6%
Age (n, %)
40 to 49 years	108	8.0%	29	7.5%	22	7.1%	7	9.1%
50 to 59 years	285	21.2%	66	17.0%	57	18.3%	9	11.7%
60 to 64 years	195	14.5%	62	16.0%	51	16.4%	11	14.3%
65+ years	757	56.3%	231	59.5%	181	58.2%	50	64.9%
Mean ± SD	67.4	12.5	67.8	11.6	67.5	11.4	68.9	12.3
Geographic region (n, %)
Northeast	236	17.5%	47	12.1%	41	13.2%	6	7.8%
Midwest	634	47.1%	201	51.8%	157	50.5%	44	57.1%
South	303	22.5%	87	22.4%	70	22.5%	17	22.1%
West	172	12.8%	53	13.7%	43	13.8%	10	13.0%
Healthplan type (n, %)
HMO	434	32.3%	122	31.4%	99	31.8%	23	29.9%
PPO	815	60.6%	234	60.3%	185	59.5%	49	63.6%
CDHP	48	3.6%	11	2.8%	10	3.2%	1	1.3%
Other commercial	48	3.6%	21	5.4%	17	5.5%	4	5.2%
Race (n, %)	n/a*
Caucasian/White			172	44.3%	147	47.3%	25	32.5%
African American/Black			9	2.3%	8	2.6%	1	1.3%
Asian/Pacific Islander			5	1.3%	4	1.3%	1	1.3%
Not specified			202	52.1%	152	48.9%	50	64.9%
Smoking status (n, %)	n/a*
Active smoker			90	23.2%	81	26.0%	9	11.7%
Former smoker			141	36.3%	122	39.2%	19	24.7%
Never smoked			40	10.3%	34	10.9%	6	7.8%
Unknown			117	30.2%	74	23.8%	43	55.8%

Notes: Age, geographic region, and healthplan type were captured via claims data at the index date, while race and smoking status were identified from the medical records.

* Not applicable, data are only available in medical records, not the claims data.

Abbreviations: HMO, health maintenance organization; PPO, preferred provider organization; CDHP, consumer-driven health plan; SD, standard deviation.

Table 2 Primary outcome – positive predictive value for pneumonia in claims

	Number abstracted	Number of documented pneumonia diagnosis	PPV (%)	(95% CI)
All pneumonia patients	388	311	80.2	(75.8–84.0)
By place of service
Inpatient hospitalization/emergency department visit	185	162	87.6	(81.9–92.0)
Outpatient/office visit	203	149	73.4	(66.8–79.3)
By medical record type
Paper	101	81	80.2	(71.1–87.5)
Electronic medical records (EMR)	150	110	73.3	(65.5–80.2)
Hybrid of paper and EMR	137	120	87.6	(80.9–92.6)

Abbreviation: PPV, positive predictive value; CI, confidence interval.

Table 3 Pneumonia symptoms captured from medical charts

	All medical records (N=388)		Medical record status
			Documented pneumonia diagnosis (N=311)		No documented pneumonia diagnosis (N=77)
Symptoms (n, %)
Cough	238	61.3%	215	69.1%	23	29.9%
Fever	101	26.0%	91	29.3%	10	13.0%
Chest pain	70	18.0%	66	21.2%	4	5.2%
Chills	64	16.5%	59	19.0%	5	6.5%
Dyspnea	209	53.9%	188	60.5%	21	27.3%
Rales	99	25.5%	88	28.3%	11	14.3%
Rhonchi	112	28.9%	107	34.4%	5	6.5%
Wheezing	165	42.5%	151	48.6%	14	18.2%
Distant breath sounds	121	31.2%	111	35.7%	10	13.0%
Temperature >100°F (37.8°C)	51	13.1%	45	14.5%	6	7.8%
Number of symptoms (n, %)
No symptoms reported	90	23.2%	49	15.8%	41	53.2%
1 symptom	39	10.1%	29	9.3%	10	13.0%
2 symptoms	39	10.1%	29	9.3%	10	13.0%
3 symptoms	40	10.3%	37	11.9%	3	3.9%
4+ symptoms	180	46.4%	167	53.7%	13	16.9%

Table 4 Patients with available results for diagnostic tests recorded in medical charts and the proportion with abnormal results

	All medical records (N=388)		Medical record status
			Documented pneumonia diagnosis (N=311)		No documented pneumonia diagnosis (N=77)
Respiratory rate test	264	68.0%	231	74.3%	33	42.9%
Results available in chart	264		231		33
Abnormal (<12 or >20 breaths per minute)	142	53.8%	127	55.0%	15	45.5%
Heart rate test	295	76.0%	256	82.3%	39	50.6%
Results available in chart	294		255		39
Abnormal (<60 or >100 bpm)	131	44.6%	120	47.1%	11	28.2%
Chest X-ray test	282	72.7%	242	77.8%	40	51.9%
Results available in chart	270		231		39
Abnormal*	231	85.6%	207	89.6%	24	61.5%
Chest CAT scan test	86	22.2%	77	24.8%	9	11.7%
Results available in chart	83		74		9
Abnormal*	74	89.2%	67	90.5%	7	77.8%
Sputum Gram stain test	71	18.3%	67	21.5%	4	5.2%
Results available in chart	58		55		3
Abnormal (positive)	40	69.0%	37	67.3%	3	100.0%
Sputum culture test	78	20.1%	74	23.8%	4	5.2%
Results available in chart	62		58		4
Abnormal (positive, isolated organism)	27	43.5%	25	43.1%	2	50.0%
Blood culture test	144	37.1%	133	42.8%	11	14.3%
Results available in chart	133		123		10
Abnormal (positive, isolated organism)	12	9.0%	10	8.1%	2	20.0%

Notes: The proportion of charts with abnormal results are based on the denominator of charts with available results.

* Abnormal included any of the following notes: “consolidation”, “pleural effusion”, “fluid”, “infiltrate”, “haze”, or “consistent with pneumonia”.

Abbreviations: bpm, beats per minute; CAT, computerized axial tomography.

Table 5 Antibiotics use identified in medical charts

	All medical records (N=388)		Medical record status
			Documented pneumonia diagnosis (N=311)		No documented pneumonia diagnosis (N=77)
Antibiotics (n, %)
Azithromycin	97	25.0%	90	28.9%	7	9.1%
Clarithromycin	9	2.3%	9	2.9%	0	0.0%
Erythromycin	0	0.0%	0	0.0%	0	0.0%
Doxycycline	11	2.8%	10	3.2%	1	1.3%
Ciprofloxacin	22	5.7%	20	6.4%	2	2.6%
Gemifloxacin	1	0.3%	1	0.3%	0	0.0%
Gatifloxacin	1	0.3%	1	0.3%	0	0.0%
Levofloxacin	100	25.8%	93	29.9%	7	9.1%
Moxifloxacin	60	15.5%	51	16.4%	9	11.7%
Sparfloxacin	0	0.0%	0	0.0%	0	0.0%
Trovafloxacin	0	0.0%	0	0.0%	0	0.0%
Ceftriaxone	94	24.2%	88	28.3%	6	7.8%
Amoxicillin	1	0.3%	1	0.3%	0	0.0%
Amoxicillin with clavulanate	10	2.6%	8	2.6%	2	2.6%
Ampicillin	1	0.3%	1	0.3%	0	0.0%
Patients with ≥1 antibiotics prescribed	275	70.9%	248	79.7%	27	35.1%