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Table 3 Missingness and summary statistics for anti-hypertensive medications

From: A data quality assessment to inform hypertension surveillance using primary care electronic medical record data from Alberta, Canada

Data element

Summary

Males

N = 23,486

Females

N = 24,889

Anti-hypertensive medication

No. patients with prescription at any time, n (%)

21,544 (91.7)

23,184 (93.1)

Mean prescriptions per patient, n (SD)

12.1 (18.0)

12.0 (17.4)

Median prescriptions per patient, n (IQR)

6.0 (10)

6.0 (11)

Medication name

No. records missing med name, n (%)

0 (0)

0 (0)

Unique values, n

86

87

3 most frequent values, n (%)

‘Ramipril’: 33,109 (12.7)

‘Amlodipine’: 27,772 (10.7)

‘Hydrochlorothiazide’: 26,238 (10.1)

‘Hydrochlorothiazide’: 40,537 (14.6)

‘Amlodipine’: 26,892 (9.7)

‘Ramipril’: 25,721 (9.3)

Start date

No. records missing start date, n (%)

0 (0)

0 (0)

Unique values, n

5471

5604

Stop date

No. records missing stop date, n (%)

34,404 (13.2)

39,686 (14.3)

Unique values, n

5664

5751

Stop date occurs before start date, n (%)

2272 (0.9)

2364 (0.9)

Drug identification number (DIN)

No. records missing DIN, n (%)

135,564 (52.1)

150,923 (54.3)

Unique values, n

1175

1238

3 most frequent values, n (%)

‘326844’: 5264 (4.2)

‘878928’: 5262 (4.2)

‘2123282’: 4324 (3.5)

‘326844’: 7091 (5.6)

‘878928’: 6265 (4.9)

‘2123282’: 3452 (2.7)

Strength

No. records missing strength, n (%)

22,914 (8.8)

32,396 (11.7)

Unique Values, n

95

99

Median (IQR)

12 (35)

20 (35)

Dose

No. records missing dose, n (%)

5428 (2.1)

7387 (2.7)

Unique values, n

2048

2730

3 most frequent values, n (%)

‘1’: 202,129 (79.3)

‘0.5’: 15,563 (6.1)

‘2’: 8635 (3.4)

‘1’: 208,017 (77.0)

‘0.5’: 18,644 (6.9)

‘2’: 7829 (2.9)

Frequency

No. records missing frequency, n (%)

24,013 (9.2)

33,261 (12.0)

Unique values, n

133

117

3 most frequent values, n (%)

‘QD’: 140,843 (59.6)

‘OD’: 45,494 (19.3)

‘BID’: 32,140 (13.6)

‘QD’: 145,261 (59.5)

‘OD’: 52,094 (21.3)

‘BID’: 27,764 (11.4)

Duration count

No. records missing duration, n (%)

33,013 (12.7)

38,379 (13.8)

Unique values, n

3507

3692

3 most frequent values, n (%)

‘3’: 51,704 (22.8)

‘100’: 50,550 (22.2)

‘90’: 21,444 (9.4)

‘3’: 51,928 (21.7)

‘100’: 49,245 (20.6)

‘90’: 20,498 (8.6)

Duration unit

No. records missing duration unit, n (%)

39,628 (15.2)

47,796 (17.2)

Unique values, n

5

5

3 most frequent values, n (%)

‘Day’: 139,344 (63.2)

‘Month’: 72,838 (33.0)

‘Week’: 5893 (2.7)

‘Day’: 145,621 (63.4)

‘Month’: 77,349 (33.7)

‘Week’: 4025 (1.8)

Dispensed count

No. records missing dispensed count, n (%)

28,376 (10.9)

33,779 (12.2)

Unique values, n

3688

3732

Median (IQR)

100 (90)

91 (95)

Dispensed form

No. records missing dispensed form, n (%)

74,277 (28.5)

93,218 (33.6)

Unique values, n

3

5

3 most frequent values, n (%)

‘Tab’: 158,009 (84.9)

‘Capsule’: 27,994 (15.1)

‘Bottle’: 1 (0)

‘Tab’: 161,436 (87.6)

‘Capsule’: 22,859 (12.4)

‘Bottle’: 3 (0)

Reason for medication

No. records missing reason, n (%)

199,924 (76.8)

210,112 (75.7)

Unique values, n

281

322

3 most frequent values, n (%)

‘Hypertension, CHF’: 21,278 (35.3)

‘Hypertension, Angina’: 11,743 (19.5)

‘Hypertension’: 7711 (12.8)

‘Hypertension, CHF’: 20,928 (31.0)

‘Hypertension, Angina’: 12,268 (18.2)

‘Hypertension’: 10,337 (15.3)

  1. IQR interquartile range, SD standard deviation